WO1993022471A1

WO1993022471A1 - Fe-Cr ALLOY EXCELLENT IN WORKABILITY

Info

Publication number: WO1993022471A1
Application number: PCT/JP1993/000580
Authority: WO
Inventors: Mitsuyuki Fujisawa; Yasushi Katoh; Yoshihiro Yazawa; Satoshi Ohwada; Keiichi Yoshioka; Fusao Togashi; Susumu Satoh
Original assignee: Kawasaki Steel Corporation
Priority date: 1992-04-30
Filing date: 1993-04-30
Publication date: 1993-11-11
Also published as: EP0597129A4; EP0597129A1; KR100253543B1

Abstract

An Fe-Cr alloy having an excellent workability over a wide range of the Cr content (e.g. 3-60 wt.%) by limiting the total content of C, N, O, P and S to 100 ppm or less. Fe-Cr alloys with various characteristics can be obtained by adding various combinations of the following element groups (1 to 4) to the Fe-Cr alloy of the basic composition: (1) a group consisting of Ni, Co and Cu with a total content of the elements in a specified range, contributing to an increase in acid resistance; (2) a group consisting of Al, Si and Mn and/or a group consisting of Ca, Mg and REM each with a total content of the elements in a specified range, contributing to an increase in oxidation resistance; (3) a group consisting of Ti, Nb, Zr, V, Ta, W and B with a total content of the elements in a specified range, contributing to an increase in high-temperature strength, and (4) a group consisting of Mo alone with a content thereof in a specified range, contributing to an increase in pitting resistance.

Description

Description Title of invention

F e—Cr alloy with excellent workability

The present invention relates to a Fe-Cr alloy having excellent workability.

The present invention relates to a Fe—Cr alloy having excellent acid resistance in addition to workability.

The present invention also relates to a Fe-Cr alloy having excellent oxidation resistance in addition to workability. The present invention further relates to a Fe—Cr alloy having excellent acid resistance and oxidation resistance in addition to workability. Background art

In general, Fe-Cr alloys are known as materials with excellent corrosion resistance, but various improvements in physical properties of Fe-Cr alloys, including improvements in corrosion resistance and workability, have been proposed as shown below. .

Japanese Examined Patent Publication No. 63-58904 discloses a ferritic stainless steel with a Cr content of 11.0 to 16.0% by weight, especially with a specified Ti content and excellent overhangability and secondary workability. Suggests steel.

Japanese Patent Publication No. 64-6264 discloses a Fe-Cr alloy with a Cr content of 8.0 to 35.0% by weight, particularly containing a specific amount of each of Si, Mn and Nb and having excellent rust resistance. An annealed material is proposed. In Japanese Patent Publication No. 2-1902, a Fe—Cr alloy with a Cr content of more than 20.0% by weight and less than 25% by weight, particularly when used for welding, which contains Mo, Mn and Nb in specific amounts, respectively, has a high temperature resistance. We have proposed corrosion-resistant ferrite stainless steel with excellent cracking and weld toughness. '

Japanese Patent Application Laid-Open Publication No. 186451/1986 discloses that the Cr content is 25 to 50% by weight. We have proposed an e-Cr alloy that contains Si, Mn, and Mo in particular and has excellent sour resistance.

Japanese Patent Application Laid-Open No. 62-267450 proposes a high-purity ferritic stainless steel, which is a Fe—Cr alloy containing 16 to 19% by weight of Cr and contains particularly a specific amount of Mo and has excellent intergranular corrosion resistance. are doing.

Japanese Patent Application Laid-Open No. 112 & 7253 discloses that a Cr content is 15 to 26% by weight and an A1 content is 4 to 6% by weight. The oxidation resistance is a Fe-Cr-Al alloy containing a small amount of a rare earth element. A1 containing ferritic stainless steel with excellent manufacturability is proposed.

Japanese Unexamined Patent Publication (Kokai) No. 232344/1990 discloses a Fe-Cr alloy containing 25.0 to 30.0% by weight of Cr, particularly a ferrite containing a specific amount of M0 and having excellent bioadhesion resistance and seawater resistance. Series stainless steel is proposed.

JP-A-3-2355 discloses a Fe-Cr alloy with a Cr content of 16.0 to 25.0% by weight, particularly containing a specific amount of Nb in the ratio of the total amount of C and N. Proposal of ferritic stainless steel with excellent cold workability, toughness and corrosion resistance o, Disclosure of the invention

[A] Category A inventions

In these Fe-Cr alloys, the importance of corrosion resistance is important first, so a relatively large amount of Cr is used. As a result, the ductility is reduced and the workability is not always sufficient, so if it is applied to applications that require formability such as automotive exterior materials and building exterior materials, cracks will occur during processing, or If the processing conditions are severe and processing is extremely difficult, problems have arisen, and further improvement in workability has been desired.

That is, an object of the present invention is to provide an Fe—Cr alloy with improved workability. An object of the present invention is to provide a Fe—Cr alloy having W acidity and oxidation resistance in addition to workability.

The present inventor has conducted intensive studies to achieve the above object. As a result, surprisingly, the amount of impurities such as C, N, 0, P, and S existing in the conventional Fe-Cr alloy is extremely small. The inventors have found that the e-Cr alloy is remarkably excellent in ductility, and have completed the present invention.

That is, the present invention provides a workability characterized by a Cr content of 3 to 60% by weight, a total amount of C, N, 〇, P and S of 10 Oppm or less, and a balance of Fe and unavoidable impurities. Provide excellent new Fe-Cr alloy.

According to the present invention, a Cr content is 5 to 60% by weight, a total amount of C, N, 0, P and S is 10 Oppm or less, and at least one selected from Ni, Co and Cu is described below. Provided is a Fe-Cr alloy excellent in workability and acid resistance, characterized in that it is contained in an amount satisfying the formula (1) and the balance is Fe and unavoidable impurities.

0.01% by weight ≤ Ni + Co + 2Cu ≤ 6% by weight …… (1) In addition, the present invention provides: 1: a content of 3 to 60% by weight, a total amount of C, N, 〇, P and S of 100 ppm or less, and one kind selected from Si, Mn and A1 The above is contained in an amount that satisfies the following formula (2) and Z or one or more selected from Ca, Mg and rare earth elements (REM) in an amount that satisfies the following formula (3), with the balance being Fe and unavoidable impurities. Provided is a Fe-Cr alloy having excellent workability and oxidation resistance.

0.1% by weight ≤3A1 + 2S i + Mn≤50% by weight …… (2)

0.00 lfi *% ≤4Ca + 4Mg + REM≤0.2% by weight ... (3) Further, the present invention provides a method for producing a composite material having a Cr content of 5 to 60% by weight, and a combination of C, N, 0, P and S. Is not more than 10 Oppm, contains at least one selected from Ni, Co and Cu in an amount that satisfies the following formula (1), and contains at least one selected from Si, Mn and A 1 Contains the amount satisfying the formula (2) and at least one selected from Z or C a, Mg and rare earth element (REM) in an amount satisfying the following formula (3), and the balance Fe and unavoidable impurities To provide a Fe-Cr alloy excellent in workability, acid resistance and oxidation resistance characterized by comprising:

0.01% by weight ≤ Ni + Co + 2 Cu ≤ 6% by weight …… (1)

0.1 0.1% by weight ≤ 3 A 1 + 2 S i + Mn ≤ 50% by weight ···· ”(2)

0.001% by weight ≤ 4Ca + 4Mg + REM ≤ 0.2% by weight '— (3) [B] Category B invention

In these Fe-Cr alloys, the importance of corrosion resistance is important first, so a relatively large amount of Cr is used. As a result, the ductility is reduced, the workability is not always sufficient, and it is difficult to finish a desired shape according to the application, and in many cases, it cannot be used. example For example, when pipes are formed and bent for use in piping applications, problems such as breakage during bending occur, and further improvement in workability has been desired.

Furthermore, the strength at high temperatures is not sufficient, and for applications exposed to high temperatures, for example, exhaust boost pipes for automobile exhaust gas, further improvements in high-temperature strength and high-temperature fatigue properties have been desired. In addition, there was a need for further improvements in applications as plant materials for the chemical industry, which require acid resistance.

That is, an object of the present invention is to provide an Fe-Cr alloy having improved workability and strength at high temperatures.

Another object of the present invention is to provide a Fe-Cr alloy having excellent acid resistance and Z or oxidation resistance in addition to workability and high-temperature strength.

The present inventor has conducted intensive studies to achieve the above-mentioned object. As a result, surprisingly, impurities such as C, N, 0, P, S and the like existing in the conventional Fe-Cr alloy are extremely small. e-Cr alloy was found to have remarkably low ductility and excellent properties, and it was selected from Ti, Nb, Zr, V, Ta, W and B for Fe-Cr alloy with very few impurities. The inventors have found that the alloy at a specific amount of at least one of the above species has improved strength at high temperatures, and completed the present invention.

According to the present invention, the Cr content is 3 to 60% by weight, the total amount of C, N, 0, P, and S is 1 O Oppm or less, and Ti, Nb, Zr, V, Ta, W, and B are selected. The present invention provides a Fe-Cr alloy excellent in workability and high-temperature strength, characterized by containing at least one kind satisfying the following formula (1) and comprising the balance of Fe and inevitable impurities. 0.0 i% ≤T i + Nb + Zr + V + Ta + W-h50 B≤ 6E *%

(1) According to the present invention, the Cr content is 5 to 60% by weight, the total f of C, N, 0, P and S is 10 Oppm or less, Ti, Nb, Zr, V, Ta, At least one selected from W and B is contained in an amount satisfying the following formula (1), and at least one selected from Ni, Co and Cu is contained in an amount satisfying the following formula (2). An Fe-Cr alloy excellent in workability, high-temperature strength and acidity characterized by being composed of e and ^ I evasive impurities is provided.

0.01 m &% ≤T i + Nb + Z r + V + T a + W + 50B≤ 6% by weight

…… (1)

0.01 weight ^ Ni + Co + 2Cu≤6% by weight (2) According to the present invention, the Cr content is 3 to 60% by weight, and the total amount of C, N, 0, P and S is 1%. O Oppm or less, containing at least one selected from Ti, Nb, Zr, V, Ta, W and B in an amount satisfying the following formula (1), and further selected from A1, Si and Mn Contains at least one kind satisfying the following formula (3) and / or contains at least one kind selected from Ca, Mg and rare earth element (REM) satisfying the following formula (4), and the balance Fe and unavoidable Fe-Cr alloy with excellent workability, high-temperature strength and oxidation resistance characterized by being composed of chemical impurities.

0.0 lfi * M≤Ti + Nb + Zr + V + Ta + W + 50B≤6%

...... (No

0.Ι Λ% ≤ 3A1 + 2S i + Μη≤5 ΜΛ% ― (3)

0.00 lfiSM≤4Ca + 4Mg + REM≤0.2% by weight …… (4) Furthermore, according to the present invention, the Cr content is 5 to 60% by weight, the total amount of C, N, 〇, P and S is 1 O Oppm or less, and Ti, Nb, Zr, V, Ta, W and B It contains at least one selected from the group in an amount satisfying the following formula (1), and further contains at least one selected from Ni, Co and Cu in an amount satisfying the following formula (2), and further contains Al, Si and One or more selected from Mn satisfy the following formula (3), and one or more selected from Z or Ca, Mg and rare earth element (REM) satisfy the following formula (4). An Fe—Cr alloy excellent in workability, high-temperature strength, acid resistance and oxidation resistance characterized by comprising e and unavoidable impurities is provided.

0.0 \ &% ≤T i + Nb + Z r + V + Ta + W + 50 B≤ 6 m.m.%

…… (1)

0.01% by weight ≤Ni + Co + 2Cu≤6% by weight …… (2)

0.1 weight 3 A 1 +2 S i + Mn ≤ 50% by weight …… (3)

0.001% by weight ≤ 4Ca + 4Mg + REM ≤ 0.2% by weight ... (4) [C] Category C invention

In these Fe-Cr alloys, the importance of corrosion resistance is important first, so a relatively large amount of Cr is used. As a result, the ductility is reduced and the workability is not always sufficient.When applying to applications that require workability such as automotive exterior materials, building exterior materials and structures, cracks may occur during processing, or processing conditions However, there has been a problem that processing is very difficult, and further improvement in workability has been desired.

Furthermore, these Fe-Cr alloys are still insufficient in the strength of corrosion resistance. In particular, they are required to be used for automotive exterior materials that require pitting corrosion resistance, exterior materials for buildings, and acid resistance. There is a need for improvements in structural materials for chemical branding.

Furthermore, these Fe—Cr alloys do not have sufficient strength and oxidation resistance at high temperatures, and further improvement is required if they are to be used in applications such as automobile exhaust pipes that are exposed to high temperatures. a Thus, a main object of the present invention is to provide a Fe-Cr alloy with improved workability and excellent pitting resistance.

Another object of the present invention is to provide a Fe—Cr alloy which has improved acid resistance in addition to the above-mentioned properties.

Still another object of the present invention is to provide a Fe-Cr alloy which is excellent in workability and also excellent in acid resistance and oxidation resistance.

The present inventor has conducted intensive research to achieve the above-mentioned huge, and surprisingly,

Fe-Cr alloy with extremely small amount of impurities such as C, N, 0, P, S, etc. existing in Fe-Cr alloy has remarkably excellent ductility and excellent corrosion resistance I found something.

The addition of a specific amount of Mo to the Fe-Cr alloy with a reduced amount of impurities significantly improves the pitting corrosion resistance, and further adds a specific amount of at least one of N'i, Co, and Cu It has been found that acid resistance can be improved by this.

The oxidation resistance is remarkably improved when one or more selected from A1, Si and Mn is added in a specific amount and / or one or more selected from Ca, Mg and REM is further added in a specific amount. And found that the present invention was completed.

That is, according to the present invention, the Cr content is 5 to 60% by weight, the total amount of C, Ν, · 0, P and S is 100 ppm or less, and the M 0 content is 0.5—20. % By weight, and the balance An Fe-Cr alloy comprising Fe and unavoidable impurities is provided. According to the present invention, the Cr content is 5 to 60% by weight, the total amount of C, N, 〇, P and S is 100 ppm or less, and the Mo content is 0.5 to 20% by weight. Excellent workability, pitting corrosion resistance and corrosion resistance characterized by containing at least one selected from Ni, Cu and Co in an amount that satisfies the following formula (1) and consisting of the balance of Fe and unavoidable impurities. Fe-Cr alloy is provided.

0.01 weight ^ Ni + Co + 2Cu≤6% by weight (1) According to the present invention, the Cr content is 5 to 60% by weight, and the total amount of C, N, 〇, P and S is 1%. O Oppm or less, 1 ^ 0 content is 0.5 to 20% by weight, and at least one selected from A1, Si and Mn is an amount satisfying the following formula (2) and no or Ca, Mg and Excellent in workability, pitting corrosion resistance and oxidation resistance characterized by containing at least one element selected from rare earth elements (REM) in an amount satisfying the following formula (3) and being composed of the balance of Fe and unavoidable impurities. Fe-Cr alloy provided o

0.1 weight 3 A 1 +2 S i + Mn ≤ 50% by weight-(2)

0.00 lfiS% ≤4 Ca + 4Mg + REM≤0.2% by weight (3) Further, according to the present invention, the Cr content is 5 to 60% by weight, and C, N, 0, P and S The total amount is 100 ppm or less, the Mo content is 0.5 to 20% by weight, and at least one selected from Ni, Cu and Co is contained in an amount satisfying the following formula (1), and A1, Si and One or more selected from Mn satisfy the following formula (2) and / or one or more selected from Ca, Mg and rare earth elements (REM) satisfy the following formula (3), and the balance Fe and inevitable Characteristic impurities The present invention provides a Fe—Cr alloy excellent in workability, pitting corrosion resistance, acid resistance, and oxidation resistance.

0.01% by weight ≤ Ni + Co + 2 Cu ≤ 6% by weight-(1)

0.1 wt% ≤3A1 + 2S ί + Μη≤50 wt% "…-(2) G. 001 wt% ≤4 Ca + 4Mg + REM≤0.2 wt% —… (3) [D] Category D About the invention

Since these Fe-Cr alloys emphasize corrosion resistance first, relatively large amounts of Cr are used. As a result, ductility is reduced and workability is not always sufficient.If it is applied to sinks for home sinks, exterior materials for buildings, exterior materials for automobiles, etc., cracks may occur during processing or δ There is a problem that processing becomes difficult when strict conditions are required, and further improvement in workability has been desired.

In addition, these Fe-Cr alloys have excellent corrosion resistance, but are still insufficient, and are especially required for water heater cans and automotive mufflers, which require pitting corrosion resistance and corrosion resistance at welds (intergranular corrosion resistance). Improvements in these properties are demanded for applications such as chemical blunts, which further require acid resistance.

In summary, a first object of the present invention is to provide a Fe-Cr alloy having improved workability and excellent pitting and weld corrosion resistance.

A second object of the present invention is to provide a Fe-Cr alloy having improved acid resistance and Z or oxidation resistance in addition to the above-mentioned properties.

The present inventor has conducted intensive studies to achieve the above object. As a result, surprisingly, the amount of impurities such as C, N, 0, P, S and the like existing in the conventional Fe--Cr alloy is extremely small. e—Cr alloy is remarkably excellent in ductility and corrosion resistance; I found something.

The addition of a specific amount of Mo to the Fe-Cr alloy with a reduced amount of impurities significantly improves the pitting corrosion resistance. In addition, the Ti, Nb, Zr, V, Ta, W and B It has been found that the corrosion resistance (intergranular corrosion resistance) of the weld is significantly improved by adding a specific amount of one or more.

In addition, we have found a series of facts that the acid resistance is significantly improved by adding a specific amount of one or more of Ni, Co, and Cu in addition to the above elements. Furthermore, it was found that the oxidation resistance was significantly improved by adding a specific amount of at least one of Si, Mn, A1 and at least one of Z or Ca, Mg, REM instead of the above elements. Was completed.

That is, according to the present invention, the Cr content is 5 to 60% by weight, the total amount of C, N, 0, P and S is 1 O Oppm or less, and the Mo content is 0.5 to 20% by weight. And at least one selected from Ti, Nb, Zr, V, Ta, W and B in an amount that satisfies the following formula (1), with the balance being Fe and unavoidable impurities. Fe—Cr alloys with excellent workability, pitting corrosion resistance, and weld corrosion resistance are provided.

0.0 i &% ≤T i + Nb + Z r + V + Ta + W + 50 B≤ 1.0 wt%

(1) According to the present invention, the Cr content is 5 to 60% by weight, the total amount of C, N, 〇, P and S is 100 ppm or less, and the Mo content is 0.5 to 20% by weight. And at least one selected from Ti, Nb, Zr, V, Ta, W and B satisfies the following formula (1), and one or more selected from Ni, Cu and Co is formula An Fe—Cr alloy is provided which is excellent in workability, pitting corrosion resistance, weld corrosion resistance and acid resistance, characterized by being contained in an amount that satisfies (2), with the balance being Fe and unavoidable impurities.

0.01% by weight ≤ Ti + Nb + Zr + V + Ta + W + 50 B ≤ 1.0% by weight

……-(1)

0.01 wt% ≤ Ni + Co + 2 Cu ≤ 6 wt% (2) According to the present invention, the Cr content is 5 to 60 wt%, and the total amount of C, N, 0, P and S is 100 wt%. pm or less, the Mo content is 0.5 to 20% by weight, and one or more selected from Ti, Nb, Zr, V, Ta, W and B satisfy the following formula (1). And at least one selected from Si, Mn and A1 satisfying the following formula (3) and at least one selected from Z or Ca, Mg and rare earth element (REM) Fe—Cr alloy with excellent workability, pitting corrosion resistance, corrosion resistance at welds and oxidation resistance characterized by containing Fe in an amount satisfying the following formula (4) and the balance being Fe and evasive impurities: Is done.

0.01% by weight ≤ Ti + Nb + Zr V + Ta + W + 50 B ≤ 1.0 weight ½

(1)

0.1% by weight ≤3AI + 2S i + Mn≤5 O weight (3) H. 00 I dragon% ≤4Ca + 4Mg + REM≤0.2 weight ............ (4) Furthermore, according to the present invention, Cr content is 5 to 60% by weight, total of C, N, 0, P and S is 100 ppm or less, M0 content is 0.5 to 20% by weight, and Ti, Nb, Zr, V, At least one selected from Ta, W and B is contained in an amount satisfying the following formula (1), and one or more selected from Ni, Cu and Co In an amount satisfying the following formula (2), and at least one selected from Si, Mn and A1 in an amount satisfying the following formula (3) and Z or C a, Mg and a rare earth element (REM) Excellent in workability, pitting corrosion resistance, welded part corrosion resistance and oxidation resistance characterized by containing at least one selected from the following formula (4) and consisting of the balance of Fe and unavoidable impurities Fe-Cr alloy provided _{

0.0 ίΜΛ% ≤Τ i + Nb + Zr + V + Ta + W + 50 B ≤ 1.0% by weight

(1)

0.01 weight ^ Ni + Co + 2Cu≤6 weight (2)

0.1 weight 3 A 1 +2 S i + Mn ≤ 50 weight (3)

0.00 lfi *% ≤4Ca + 4 g + REM≤0.2 weight (4) Brief description of drawings

1, C, N, P, 0 , graph der showing the total amount of the tensile properties of the relationship between S Ru _c

Fig. 2 is a graph showing the relationship between the total amount of C, N, P, 0, and S and the degree of corrosion.

FIG. 3 is a graph showing the relationship between the amount of Cr and the degree of corrosion.

FIG. 4 is a graph showing the relationship between Ni + Co + 2Cu and the degree of corrosion.

Fig. 5 is a graph showing the relationship between the total amount of C, N, P, 0, and S and the abnormal oxidation area.

FIG. 6 is a graph showing the relationship between the Cr content and the increase in oxidation.

Figure 7 shows the value of 3A1 + 2Si + Mn (a graph showing the relationship between weight and abnormal oxidation area). It is rough.

FIG. 8 is a graph showing the relationship between the value of 4Ca + 4Mg + REM (weight and oxide film separation area ratio).

Fig. 9 is a graph showing the relationship between the total amount of C, N, 0, P, and S and the tensile properties of Fe-18% Cr alloy.

FIG. 10 is a graph showing the relationship between Ti + Nb + Zr + V + Ta + W + 50B and the increase in high-temperature yield strength.

Fig. 11 is a graph showing the relationship between the total amount of C, N, P, 0, and S and the degree of corrosion.

FIG. 12 is a graph showing the relationship between the Cr content and the degree of corrosion.

FIG. 13 is a graph showing the relationship between i + Co + 2Cu and the degree of corrosion.

FIG. 14 is a graph showing the relationship between Ti + Nb + Zn + Ta + V + W + 50B and the degree of corrosion.

FIG. 15 is a graph showing the relationship between the Cr content and the weight loss after the oxidation resistance test. FIG. 16 is a graph showing the relationship between (3A1 + 2Si + Mn) and oxidation resistance. FIG. 17 is a graph showing the relationship between (4Ca + 4Mg + REM) and oxidation resistance.

FIG. 18 is a graph showing the relationship between the total amount of C, N, 0, P and S and the tensile properties.

FIG. 19 is a graph showing the relationship between the Mo content and the pitting potential.

Fig. 2 is a graph showing the relationship between (Ni + Co + 2Cu) wt% and acid resistance. is there.

FIG. 21 is a graph showing the relationship between (3Al + 2S i + Mn) and oxidation resistance.

FIG. 22 is a graph showing the relationship between (4Ca + 4Mg + REM) and oxidation resistance.

FIG. 23 is a graph showing the relationship between the total amount of C, N, 0, P and S and the bow extension characteristics.

FIG. 24 is a graph showing the relationship between the Mo content and the pitting potential.

FIG. 25 is a graph showing the relationship between (T i + Nb + Zr + V + Ta + W + 50 × B) wt% and intergranular corrosion resistance.

FIG. 26 is a graph showing the relationship between (Ni + Co + 2Cu) wt% and acid resistance.

FIG. 27 is a graph showing the relationship between (3Al + 2S i + Mn) and oxidation resistance.

FIG. 28 is a graph showing the relationship between (4Ca + 4Mg + REM) and oxidation resistance.

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention is composed of inventions roughly classified into four categories. The invention of each category is as follows, and will be described for each category in order. Also, the section of “Disclosure of the invention”, the section of “Example J”, and the “usability of production S_b” will be similarly explained for each power category so as to be easily understood.

Invention of CCategoryA)

The present invention is an invention that claims priority over Japanese Patent Application No. 4-1111, Japanese Patent Application No. 4-11973558, and Japanese Patent Application No. 4-1112 & 751. Claims 1 to 4 and those disclosed in FIGS. 1 to 8.

Invention of ttategoryB)

This invention is an invention claiming priority over Japanese Patent Application No. 4-1128751, Japanese Patent Application No. 4-1416153 and Japanese Patent Application No. 4-1141655. Claims 5 to 8 and FIGS. 9 to 17.

Invention of CCategoryC)

This invention is an invention that extends priority of Japanese Patent Application No. 4-1114 / 30 and Japanese Patent Application No. 4-1141 / 566, and claims & ~ 1, 2 and Fig. 1 8 to FIG. 22 are disclosed.

Invention of CCategoryD)

The present invention is an invention that prioritizes Japanese Patent Application No. 4-111252 and is disclosed in claims 13 to 16 and FIGS. 23 to 28.

4 [A] Category A inventions

The following is a more detailed description of this effort. (I) First, the Fe—Cr alloy of the present invention having excellent workability will be described. Figure 1 shows the effects of C and N on the change in elongation and the change in power (yield strength) obtained by the bow I tension test (JISZ-2241) for the cold-rolled annealed sheet of Fe—18% Cr alloy. The effect of the total amount of C, N, 0, P and S is shown, but it is clear that the total amount of C, N, 0, P and S is not more than 10 Opm, and that the ductility is remarkably excellent.

In Fig. 1, the change in elongation (%) and the change in heat resistance (yield strength) (N / Picture ² ) are the values of C + N + O + S + P = 500 ppm for each alloy component. This shows the difference in tensile properties between the two. The basic tensile properties are as follows.

Fe-18Cr, C + N + 0 + S + P = elongation at 500ppm 30%, resistance to 330N / country ²

Fe-30Cr, C + N + O + S + P = 500ppm, elongation 25%, power 450N / 豳^{2 In} the Fe-Cr alloy of the present invention, the total amount of C, N, 0, P and S Is less than 100 ppm. As described above, at 100 ppm or less, ductility, that is, workability is remarkably excellent. On the other hand, as the content exceeds 100 ppm, the ductility decreases and the workability decreases.

Furthermore, in the Fe-Cr alloy of the present invention, the Cr content is 3 to 60% by weight, preferably 5 to 30% by weight. If it is less than 3% by weight, the corrosion resistance is inferior. If it exceeds 60% by weight, sufficient workability cannot be obtained even if C, N, 0, P and S are reduced.

In other words, Fe—Cr alloys with a total content of C, N, 0, P, and S of 10 Oppm or less and a Cr content of 3 to 60% by weight have remarkably excellent workability and excellent corrosion resistance.

If necessary, Al, Mo, Nb, B, Si, Mn, Cu, Ni, Co, Other elements such as Ca can also be added.

In order to produce the Fe-Cr alloy excellent in workability of the present invention, high-purity electrolytic iron and electrolytic Cr may be used as raw materials. In addition, high-purity elements are also used as raw materials for elements added as necessary. Les, the raw material of the displacement is also the major impurity is oxygen, dissolved at a high ultra-high vacuum than 10_ ⁷ 10 rr to remove this oxygen, producing F e-Cr alloy of the present invention by Sekizosu Rukoto can do.

In addition, the effect of the component system of the present invention can be sufficiently obtained even in a hot-rolled annealed sheet or a cold-rolled annealed sheet, and the surface izLh of the cold-rolled annealed sheet can be sufficiently obtained by BA, 2B, 2D, HL, polishing, etc. Needless to say, its characteristics are utilized.

(II) Next, the Fe—Cr alloy of the present invention, which is excellent in acid resistance in addition to workability, will not be described.

Fig. 2 is a graph showing the relationship between the total amount of C, N, P, 0 and S and the degree of corrosion for the Fe-36% Cr-3.2% Co alloy. It is clear that the degree of corrosion is very low.

Figure 3 shows the relationship between the Cr content and the degree of corrosion of the Fe-Cr-1.6i-1.4% Co alloy when the total amount of C, N, 0, P and S is 10 Oppm or less. This is shown in the graph for cases exceeding 10 ppm. Fig. 3 shows that the alloy with C + N + 0 + P + S less than 10 O ppm has a significantly lower degree of corrosion than the alloy with more than 100 ppm, and the tendency is higher when the Cr content is 5 wt% or more. Is clearly notable.

Figure 4 6—38% 〇]: This is a diagram showing the relationship between Ni + Co + 2Cu and the degree of corrosion for alloys (however, C + N + 0 + P + S = 62 ppm). It has been clarified that the corrosion rate decreases when the value of + 2Cu exceeds 0.01% by weight.

Hereinafter, the components of the alloy composition of the present invention will be described.

Cr: 5 to 60% by weight, preferably 10 to 40% by weight. When the Cr content is within this range, an alloy having excellent acid resistance can be obtained as described above. Excessive Cr content is undesirable because it causes a reduction in workability. The effect on the improvement of acid resistance is also saturated.

C, N, 0, P, S: The total amount of these elements is 10 Oppm or less, preferably 85 ppm or less. As described above, when the content is 10 Oppm or less, it exhibits excellent acid resistance in combination with other conditions and is excellent in workability.

Cu, Ni, Co; All of these elements are important and useful elements that have the effect of improving the acid resistance of the alloy. The alloy of the present invention contains one or more selected from these elements, and the amount is within a range that satisfies the following equation.

0.01% by weight≤Ni + Co + 2Cu≤6% by weight ... (1) Preferably, 0.05% by weight≤Ni + Co + 2Cu≤5.0% by weight (la)

If the amount of Ni, Co, Cu is less than the above range, the corrosion resistance is poor, and if it is too large, the productivity of the alloy is poor.

The preferred contents of Ni, Co, and Cu are as follows, for the same reasons as described above.

Ni: 0.05-5.0% by weight

C 0; 0.05-5.0% by weight

Cu; 0.05 to 2.5% by weight An Fe-Cr alloy satisfying the above conditions exhibits excellent workability and extremely excellent corrosion resistance.

The Fe—Cr alloy of the present invention, which has excellent processability and acid resistance, can be used as a raw material in ultra-high purity electrolytic Fe, electrolytic, electrolytic Ni, electrolytic, electrolytic Co, iodide Ti, electrolytic reduced Nb, molten salt electrolytic Zr. , Reduction V, electrolytic Ta, electrolytic reduction W, high-purity ferro-bore, etc.

The main impurity in both contents is oxygen, and the F of the present invention is obtained by dissolving and producing under an ultra-high vacuum of more than 10 to ¹⁵ rr, preferably more than 10 to ⁷⁰ rr to remove this oxygen. e—Cr alloy can be manufactured.

(IίI) Further, the Fe—Cr alloy of the present invention having excellent workability and oxidation resistance will be described.

Figure 5 shows C, N, 0, P and S for Fe-24 ^ Cr-0.1% REM (Y: 0.05%, La: 0.03%, Ce: 0.02%) alloy. Is a graph showing the relationship between the total amount of C and the abnormal oxidation area after the continuous oxidation test. It is clear that the abnormal oxidation area is extremely small when the total amount of C, N, 0, P, and S is 1 G 0 ppm or less. It's obvious o

Figure 6 This is a graph showing the relationship between the Cr content and the oxidation increase after the oxidation test for the 6-〇1: -1 alloy. If the total amount of C, N, 0, P and S is less than 10 Oppm It has been clarified that when the Cr content is 3.0% by weight or more, the oxidation weight increase is significantly reduced.

Figure 7 shows that the value of (3Al + 2S i + Mn) for the Fe--28% Cr alloy with a total amount of 5 lppm of C, N, P, 0 and S

2 days It is a graph which shows the effect, It is clear that when the above value is 0.1% by weight or more, the value of the abnormal oxidation area decreases.

Figure 8 is C, N, 0, the total amount of P and S with respect Fe- 26% Cr alloy ^½ of 72ppm, (4 C a + 4 M g + REM) values and oxide film after repeated heating test剝

^¾ . The relationship with the area separation rate is shown. It is clear that when the above value is 0.001% or more, the oxide film separation area rate is significantly reduced.

Hereinafter, components and embodiments of the alloy composition of the present invention will be described. The Fe-Cr alloy of the present invention having excellent workability and oxidation resistance has the following three aspects, each of which will be described.

(1) First embodiment of the present invention

Cr: 3 to 60% by weight, preferably 10 to 40% by weight. When the Cr content is in this range, the alloy is combined with other conditions to provide an alloy having excellent oxidation resistance. Excessive Cr content is not preferable because it causes a reduction in workability and saturates the effect of improving oxidation resistance.

C, N, 0, P, S: The total amount of these elements is 10 Oppm or less, preferably 85 ppm or less. By satisfying this condition, abnormal oxidation is suppressed. Then, when these conditions are combined with other conditions, an alloy having excellent oxidation resistance is obtained, and at the same time, an alloy having excellent ductility and good workability is obtained.

έ Si, Mn, Al: The alloy of this embodiment contains one or more of these elements,

Satisfies the following formula (2), preferably (2a).

0.1% by weight ≤3A1 + 2S i + Mn≤50% by weight …… (2)-Preferably, 0.5 m% ≤ 3 A 1 + 2 S i + Mn ≤ 25-… "(2a) Due to such a range, combined with other conditions, it is remarkably excellent in oxidation resistance If these elements are contained excessively and the value of 3A1 + 2Si + Mn exceeds the range of the formula (2), it becomes difficult to produce an alloy, so that it is difficult to produce an alloy. Excess content should be avoided.

The preferred contents of each individual element and the reasons are as follows.

S i: 0. 1 10.0 weight

If the amount is less than 0. I% by weight, it is effective but not remarkable. If it exceeds 10% by weight, the decrease in productivity becomes noticeable.

Mn: 0.1 to 5.

Less than 0.1% by weight is effective but not significant. If it exceeds 5% by weight, the decrease in productivity becomes noticeable.

A1: 0. 4.0% by weight

Less than 0.1% by weight is effective but not significant. If the content exceeds 4.0% by weight, the decrease in productivity becomes significant.

Since Fe-Cr alloys satisfying the above conditions have excellent oxidation resistance and workability, they can be suitably used for automobile exhaust gas system members, pipes used in high-temperature repeated oxidation environments, and the like.

(2) Second embodiment of the present invention

With respect to the Cr content, the contents of C, N, 0, P and S, and the preferred content of Fe, what has been described in the first embodiment also applies in this embodiment.

In the alloy of the second embodiment, at least one selected from Ca, Mg, and REM The upper part is included. The content of these elements satisfies the following formula (3), preferably (3a).

0.00 1% by weight ≤4 Ca + 4Mg + REM ≤ 0.2% by weight …… (3) Preferably,

0.005% by weight ≤4 Ca + 4Mg + REM ≤ 0.15 weight …… (3a) By satisfying this condition, combined with other conditions, excellent oxidation resistance and good workability An Fe—Cr alloy having the following formula is obtained.

These elements remarkably improve the protection of the oxide film formed on the surface of the alloy of the present embodiment, suppress abnormal oxidation which tends to occur in ultra-thin materials, and improve the adhesion between the oxide film and the base material. It has the function of making it good.

However, if these elements are excessively contained (4C a + 4Mg +

When the value of (REM) exceeds 0.2% by weight, surface defects of the alloy tend to occur, which is not preferable.

The more preferable contents of Ca, Mg, and REM and the reasons therefor are as follows.

C a: 0.002 to 0.0 1% by weight

Even if less than 0.002% by weight, the effect is not remarkable. If the content exceeds 0.01% by weight, the decrease in productivity becomes noticeable.

Mg: 0.002 to 0.0 1% by weight

Even if less than 0.002% by weight, the effect is effective, but not remarkable. If the content exceeds 0.01% by weight, the decrease in productivity becomes noticeable.

REM: 0.005 to 0.1% by weight Even if the content is less than 0.05% by weight, the effect is obtained but is not remarkable. If it exceeds 0.1% by weight, the effect will be saturated and the cost will increase.

Such an alloy of the second aspect of the present invention can be used for the same applications as the alloy of the first aspect.

(3) Third embodiment of the present invention β An alloy that satisfies both the conditions of the alloy of the first embodiment and the conditions of the alloy of the second embodiment of the present invention described in detail above, that is, the Cr content is 3-6% by weight, C,

The total amount of N, 0, P, and S is 10 O ppm or less, and at least one selected from Si, Mn, and A1 is contained in an amount satisfying the above formula (2), and ,

Fe—Cr alloys containing at least one selected from Ca, Mg and rare earth elements (REM) in an amount satisfying the above formula (3) are also alloys having even better oxidation resistance and workability. It is preferably used for the above applications.

In order to produce the Fe-Cr alloy of the present invention including these three embodiments, the raw materials used are ultra-high-purity electrolytic iron, electrolytic chromium, zone melt silicon, molten salt electrolytic manganese, and molten salt electrolytic. Use aluminum, molten salt electrolytic calcium, electrolytic reduced magnesium, electrolytic reduced rare earth metal. Les, the raw material of the displacement also major impurity is oxygen, 1 0 in order to remove this oxygen - of the present invention by ⁵ † 0 rr high solubility under ultrahigh vacuum than, be鐯造F e- C r alloy can be manufactured.

(IV) Finally, the Fe-Cr alloy of the present invention, which is excellent in acid resistance and oxidation resistance in addition to workability, will be described.

This alloy of the present invention is obtained by taking into account, in addition to the alloy composition particularly excellent in acid resistance described in (II), the alloy composition particularly excellent in oxidation resistance described in (III). did Therefore, only the embodiment will be described below, and the detailed description is the same as that described in (III) and (II), and thus will be omitted.

This invention has three embodiments as in the invention of (III). C + N + 0 + S + P≤1 O Oppm, and in addition to Cr: 5 to 60% by weight, it varies. part

Only ¾ will be described below for each mode.

(1) First embodiment of the present invention

At least one selected from Ni, C0 and Cu is contained in an amount satisfying the following formula (1).

0.01% by weight ≤ Ni + Co + 2Cu ≤ 6% by weight ...... (1) Preferably,

0.05% by weight ≤Ni + Co + 2Cu≤5.0% by weight …… (la) Contains at least one selected from Si, Mn and A1 in an amount that satisfies the following formula (2).

0.1 weight 3 A 1 + 2S i + Mn ≤ 50% by weight …… (2)

Preferably,

0.5wt ^ 3Al + 2S i + Mn≤25wt% …… (2a)

(2) Second embodiment of the present invention

0.01 weight ^ Ni + Co + 2Cu≤6% by weight …… (1) Preferably,

0.05% by weight ≤Ni + Co + 2Cu≤5.0% by weight …… (la) At least one selected from Ca, Mg and rare earth elements (REM) is contained in an amount sufficient to satisfy the following formula (3).

0. Hihi 1% by weight ≤4Ca + 4Mg + REM 0.2% by weight …… (3) Preferably,

0.005% by weight ≤ 4Ca + 4Mg + REM ≤ 0.15% by weight (3a) (3) Third embodiment of the present invention

At least one selected from Ni, Co and Cu is contained in an amount satisfying the following formula (1).

0.01% by weight ≤Ni + Co + 2Cu≤6% by weight-(1) Preferably,

0.05% by weight ^ Ni + Co + 2Cu≤5.0% by weight-(la) Contains at least one selected from Si, Mn and A1 in an amount satisfying the following formula (2).

0.1 weight ^ 3A1 + 2S i + Mn≤50% by weight ··· (2)

Preferably,

0.5% by weight ≤3A1 + 2S i + Mn≤25% by weight …… (2a)

It contains at least one element selected from Ca, Mg and rare earth elements (REM) in an amount satisfying the following formula (3).

0.001% by weight ≤ 4Ca + 4Mg + REM ≤ 0.2% by weight ... (3) Preferably,

0.005fi *% ≤4 Ca + 4Mg + REM≤0.15% by weight ······························································································································································································ (3_).

2 & Akira will be omitted _c

[B] Category B invention

Hereinafter, the present invention will be described in more detail.

(I) First, the Fe—Cr alloy of the present invention having excellent workability and high-temperature strength will be described.

Figure 9 shows the total amount of C, N, 0, P and S and the results of a tensile test at room temperature for the Fe-18% Cr alloy, based on the conventional alloy with the above total amount of about 500 ppm. Things. It can be seen that when the content is 100 ppm or less as compared with the conventional alloy, the elongation value is improved, the yield strength is significantly reduced, and the ductility is visibly improved. In Fig. 9, the change in elongation (%) and the change in heat resistance (yield strength) (N / mm ² ) are the same as those for C + N + 0 + S + P = 500 ppm for each alloy component. It shows the difference in tensile properties.

The basic tensile properties are as follows.

Fe - 18 Cr, elongation 30% C + N + 0 + S + P = 500 ppm,耐Ka 330NZmm ²

Fe-30 Cr, C + N + 0 + S + P = elongation at 500 ppm 25

Power resistance 450 NZmm ²

Fig. 10 is a graph showing the relationship between the value of (Ti + Nb + Zr + V + Ta + W + 5 OB) and the increase in high temperature resistance (900 ° C). %, The increase in high-temperature strength becomes 0.1 / mm ² or more, and it is clear that the strength at high temperatures improves.

Next, the composition of the alloy of the present invention will be described. .

Cr: 3 to 60% by weight, preferably 5 to 45% by weight. Within the above range If combined with other conditions of the present invention, an alloy having excellent oxidation resistance will be obtained. However, an excessive content exceeding 60% by weight is not preferable because of high cost.

C, N, 0, P, S; the total amount of these elements is 100 ppm or less, preferably 85 ppm or less. This improves the ductility of the alloy, that is, the workability, and at the same time, combines with the condition of the Cr content specified above to provide excellent oxidation resistance. If this amount exceeds 100 ppm, such excellent effects are not exhibited.

T i, Nb, Zr, V, Ta, W and B; containing one or more of these elements, and their contents are added so as to satisfy the following formula (1), preferably formula (1a).

0.0 1 wt% ≤T i + Nb + Zr + V + Ta + W + 5 0 x B≤ 6%

…… (1)

0.1 wt% ≤ Ti + Nb + Zr + V + Ta + W + 50 xB ≤ 4 wt%

(1a) By containing these elements in the above ranges, the strength at high temperatures is improved. However, if these elements are excessively blended and deviate from the range of the equation (1), the high-temperature strength is maintained, but the problem that the brittleness of the material is promoted occurs.

Further, the content of Ti, Nb, Zr, V, Ta, W or B is preferably within the following range.

T i: T i ≤ 5 (C% + N%)

Nb: 0.0% 1% by weight

Zr: 0.0% 1% by weight

V: 0.02 to 1% by weight

T a: 0.0 1% by weight W: 0.03 to 1% by weight

B: 0.0003-3% by weight

Since the alloy of the present invention that satisfies the above conditions has excellent workability and high-temperature strength, it is suitable for applications such as automobile exhaust gas pipes that require pipe forming and subsequent bending.

In order to produce the Fe—Cr alloy described in (I) of the present invention, first, ultrahigh-purity electrolytic iron and electrolytic Cr are used as raw materials.

Any of raw materials are principal impurity is oxygen, dissolved in order to remove the oxygen for example 10- ⁵ 10 rr or under ultra-high vacuum, F e of the present invention by Kagizo - producing C r alloy be able to.

(II) Next, the Fe—Cr alloy of the present invention having excellent workability, high-temperature strength and acid resistance will be described.

Figure 9 shows the total amount of C, N, 0, P and S and the results of a tensile test at room temperature for an Fe-18% Cr alloy, based on a conventional alloy with the above total amount of about 500 ppm. It is a thing. It can be seen that when the content is 10 Oppm or less as compared with the conventional alloy, the elongation value is improved, the yield strength is remarkably reduced, and the ductility is significantly improved.

FIG. 10 is a graph showing the relationship between the value of (Ti + Nb + Zr + V + Ta + W + 50B) and the increase in the high temperature resistance (900.C), where the above value is 0.01% by weight. After that, the increase in high-temperature resistance becomes 0.1 Xmm ² or more, and it is clear that the strength at high temperatures improves. .

Figure 11 shows that for Fe-36% Cr-3.2% Co alloy, C, N, P, 0 and It is a graph which shows the relationship between the total amount of S and the degree of corrosion, and it is clear that when the total amount is within 10 Oppm, the degree of corrosion is extremely low.

Fig. 12 shows the relationship between the Cr content and the degree of corrosion for the Fe-Cr-1.6% Ni-1.4% Co alloy when the total amount of C, N, 0, P and S is 10 Oppm or less. It is shown in the graph for the case of and the case where it exceeds 100 ppm. Fig. 2 shows that the alloy with C + N + 0 +? +3 less than 100 ppm has a significantly lower corrosion rate than the alloy with more than 100 ppm, and the tendency is remarkable when the Cr content is 5 wt% or more. It is clear that there is.

FIG. 13 is a diagram showing the relationship between Ni + Co + 2Cu and the degree of corrosion for the Fe—38% Cr alloy (however, C + N + 0 + P + S = 62 ppm), where Ni + Co + 2Cu It has been clarified that when the value of is more than 0.01% by weight, the degree of corrosion decreases.

Fig. 14 shows the results of Fe-46% Cr-3.0% Co-1.2% Cu alloy (C + N + 0 + P + S = 64ppm), Ti + Nb + Zr It is a figure which shows the relationship between the value (wt%) of + Ta + V + W + 5OB and the degree of corrosion. It is clear that when the above value is 0.01% by weight or more, the degree of corrosion is low. I have.

Next, the composition of the alloy of the present invention will be described.

Cr: 5 to 60% by weight, preferably 10 to 40% by weight. When the Cr content is in this range, an alloy having excellent acid resistance can be obtained as described above. Excessive Cr content is undesirable because it causes a reduction in workability. In addition, the effect on the improvement of acid resistance is saturated.

C, N, 〇, P, S: The total amount of these elements is 10 Oppm or less. 85p pm or less. As described above, when it is not more than 100 ppm, it exhibits excellent high-temperature strength and acid resistance in combination with other conditions, and also has excellent workability.

Ti, Nb, Zr, V, Ta, W and B; containing one or more of these elements, and their contents are added so as to satisfy the following formula (1), preferably formula (1a).

0.01 &% ≤T i + Nb + Z r + V + Ta + W + 50 B≤6% by weight

'… (1)

0.1% by weight≤Ti + Nb + Zr + V + Ta + W + 50B≤4% by weight

(...) (la) By containing in the above range, the strength at high temperatures is improved. However, if these elements are excessively blended and deviate from the range of Equation (1), the high-temperature strength is maintained but the brittleness of the material is promoted.

The content of Ti, Nb, Zr, V, Ta, W or B is preferably within the following range.

T i: Ti≤5 (C wt% + N wt%)

Nb: 0.01-1% by weight

Zr: 0.0 1% by weight

V: 0.02 ~: I weight%

Ta: 0.0 1% by weight

W: 0.03 to 1% by weight

B: 0.0003-0.3 weight

Cu, Ni, Co; all of these elements have the effect of improving the acid resistance of the alloy. It is a necessary and useful element. The alloy of the present invention contains one or more selected from these elements, and the amount is within a range that satisfies the following formula.

0.01% by weight ≤ Ni + Co + 2Cu ≤ 6% by weight ...... (2) Preferably, 0.05% by weight ≤ Ni + Co + 2Cu ≤ 5.0% by weight

…… (2a)

Ni; 0.05 to 5.0% by weight

C 0; 0.05-5.0% by weight

Cu; 0.05 to 2.5% by weight

The 6- (1 ^> alloy, which satisfies the above conditions, exhibits not only excellent workability and high-temperature strength, but also remarkably excellent acid resistance.

The Fe—Cr alloy described in (II) of the present invention may be, as raw materials, ultrahigh-purity electrolytic Fe, electrolytic Cr, electrolytic Ni, electrolytic Cu, electrolytic Co, iodide Ti, electrolytic reduced Nb, and molten salt Zr. , Reduction V, electrolytic Ta, electrolytic reduction W, high-purity ferroboron, and the like.

Both main impurities of the content is oxygen, F e-Cr in the 10_ oxygen to remove ⁵ t 0 rr preferably dissolved at ultra high vacuum of more than 10_ ⁷ 10 rr, more invention to铸造Alloys can be manufactured.

(III) Next, the Fe—Cr alloy of the present invention having excellent workability, high-temperature strength and oxidation resistance I will explain it.

Figure 9 shows the total amount of C, N, 0, P and S and the results of a tensile test at room temperature for the Fe-18% Cr alloy, based on the conventional alloy with the above total amount of about 500 ppm. It is a thing. It can be seen that when the content is 10 Oppm or less as compared with the conventional alloy, the value of elongation is improved, the yield strength is significantly reduced, and the ductility is improved.

FIG. 10 is a graph showing the relationship between the value of (T i + Nb + Z r + V + Ta + W + 50 B) and the increase in high-temperature resistance (900 ° C.). When the on weight percent or more increase in temperature yield strength becomes 0. INZmm ² or more, it is apparent that the strength at high temperatures is above improvement.

Figure 15 shows the oxidation resistance test results for Fe—Cr alloys with the total amount of C + N + 0 + P + S not less than 10 ppm and not more than 10 ppm (1350 k in air, 12 hr 4 is a graph showing the weight loss after removing the call. When the total content of C, N, 0, P, and S is 10 ppm or less, the properties equal to or higher than those of conventional stainless steel with a Cr content of 12% by weight or more Obviously, it is clear that low purity is achieved by high purification and resource saving is achieved.

FIG. 16 is a graph showing the results of a shochu oxidation test (1350 K in air, weight loss after 12 hr scale removal) for Fe— (15-3%)% Cr alloy. It is clear that the oxidation resistance is excellent when (3Al + 2Si + Mn) is 0.1% by weight or more.

Fig. 17 is a graph showing the results of an oxidation resistance test (weight reduction after removing 1350 K, 12 r scale in air) for Fe- (15 to 30)% Cr alloy. When (4 Ca + 4Mg + REM) is 0.001% by weight or more, it is apparent that the oxidation resistance is excellent.

Next, the composition and embodiment of the alloy of the present invention will be described. The Fe-Cr alloy of the present invention having excellent workability, high-temperature strength and oxidation resistance has the following three aspects, each of which will be described.

(1) First embodiment of the present invention

Cr: 3 to 60% by weight, preferably 5 to 45% by weight. When the content is within the above range, the alloy is combined with the other conditions of the present invention to provide an alloy having excellent oxidation resistance. However, an excessive content exceeding 60% by weight is not preferable because the cost increases.

C, N, 0, P, S; the total amount of these elements is 10 Oppm or less, preferably 85 ppm or less. By reducing the content of these elements in this way, the ductility of the alloy, that is, the workability is improved, and at the same time, the alloy is excellent in oxidation resistance in combination with the condition of the Cr content specified above. When this amount exceeds 10 Oppm, such excellent effects are not exhibited.

0.01% by weight ≤ Ti + Nb + Zr + V + Ta + W + 50 B ≤ 6%

…… (1)

0.1 wt% ≤Τ i + Nb + Zr + V + Ta + W + 50 wt%

... (1a) By containing the above amount, the strength at high temperature is improved. However, if these elements are excessively blended and deviate from the range of Equation (1), the high-temperature strength is maintained. However, the brittleness of the material is promoted.

T i: T i ≤ 5 (C weight% by weight)

Nb: 0.01-1% by weight

Zr: 0.0 1% by weight

V: 0.02 to 1% by weight

Ta: 0.01-1% by weight

W: 0.03 to 1% by weight

B: 0.0003-0.3 weight

A1, Si, Mn: Contains one or more of these elements, and the content is added so as to satisfy the following formula (3), preferably (3a).

0.1 weight ^ 3A1 + 2S i + Mn≤50% by weight (3)

0.3% by weight≤3A1 + 2S i + Mn≤30% by weight (3a) By containing these elements in the above range, the oxidation resistance is remarkably improved. However, if it is added excessively and the 3A1 + 2Si + Mn value exceeds 50% by weight, the processability deteriorates, which is not preferable.

The content of Al, Si or Mn is preferably within the following ranges.

A 1: 0.1 to 4% by weight

S i: 0.3-3% by weight

Mn: 0.5 to 10% by weight (2) Second embodiment of the present invention

With respect to the Cr content, the contents of C, N, 0, P and S, and the preferable contents of Ti, etc., the description in the first embodiment also applies in this embodiment.

In the alloy of the second embodiment, at least one selected from Ca, Mg and REM is contained as follows.

Ca, Mg, REM: These elements are not essential components in the alloy of the present invention, but if they are contained so as to satisfy the following formula (4), the oxidation resistance is further improved and favorable results are obtained. However, if these elements are excessively contained and the value of (4Ca + 4Mg + REM) exceeds 0.2% by weight, surface defects of the alloy are likely to occur, which is not preferable.

0.001M% ≦ 4 Ca + 4Mg + REM ≦ 0.2% by weight (4) The content of Ca, Mg or REM is preferably in the following range.

Ca: 0.0002-0.03% by weight

Mg: 0.0003-0.03% by weight

REM: 0.0005 to 0.15% by weight

The alloy of the present invention that satisfies the above conditions is excellent in workability, and is also excellent in high-temperature strength and oxidation resistance, so that it is suitable for applications such as exhaust pipes for automobiles.

In order to produce the Fe-Cr alloy of the present invention, first, ultrahigh-purity electrolytic iron and electrolytic Cr are used as raw materials.

Both main impurities of the raw material is oxygen, dissolved at high ultrahigh vacuum than 10 one ⁷ t or r to remove this oxygen, to produce a Fe- Cr alloy of the present invention by铸造it can. (3) Third embodiment of the present invention

An alloy that satisfies both the conditions of the alloy according to the first embodiment and the conditions of the alloy according to the second embodiment of the present invention described above, that is, a Cr content of 3 to 60% by weight, The total amount of N, 〇, P and S is not more than 10 Oppm, and one or more selected from Ti, Nb, Zr, V, Ta, W and B are represented by the formula (1 ), And contains at least one selected from Si, Mn and A1 in an amount that satisfies the formula (3), and is selected from Ca, Mg and rare earth elements (REM). Fe—Cr alloys containing at least one of the following in an amount that satisfies the formula (4) are also alloys having even better oxidation resistance and workability, and are preferably used for the above-mentioned applications. In order to produce the Fe—Cr alloy of the present invention including these three embodiments, ultrahigh-purity electrolytic iron, electrolytic chromium, zone melt silicon, molten salt electrolytic manganese, molten salt electrolytic aluminum are used as raw materials. Use molten salt electrolytic calcium, electrolytic reduced magnesium, electrolytic reduced rare earth metal. Both main impurities of the raw material is oxygen, dissolved in 1 0 one ⁵ 0 higher under ultrahigh vacuum than rr to remove this oxygen, the F e- C r alloy of the present invention by鐯造Can be manufactured.

(IV) Lastly, the OFe—Cr alloy of the present invention, which is excellent in acid resistance and oxidation resistance in addition to workability and high temperature strength, will be described.

This alloy of the present invention is obtained by adding the alloy having particularly excellent oxidation resistance described in (II) in addition to the alloy composition having particularly excellent acid resistance described in (II). Therefore, only the mode is shown below, and the detailed description is omitted because it is as described in (II) and (III).

This invention has three embodiments as in the invention of (III), and C + N + 0 + P≤ 100 ppm, Cr: 5-60% by weight, 0.01% ≤Ti + Nb + Zr + V + W + 50 B≤6% Description will be given for each mode.

(1) First embodiment of the present invention

At least one selected from Ni, Co and Cu is contained in an amount satisfying the following formula (2).

0.01 wt% ≤Ni + Co + 2Cu≤6 weight (2)

Contains at least one selected from Si, Mn and A1 in an amount that satisfies the following formula (3).

0.1 weight ^ 3 A 1 +2 S i + Mn ≤ 50% by weight (3)

(2) Second embodiment of the present invention

0.01 weight ^ Ni + Co + 2Cu≤6wt% (2)

At least one selected from Ca, Mg and rare earth elements (REM) is represented by the following formula

Contains the amount satisfying (4).

0.001% by weight ≤ 4Ca + 4Mg + REM ≤ 0.2% by weight …… (4)

(3) Third embodiment of the present invention

0.01% by weight ≤ Ni + Co + 2Cu ≤ 6% by weight (2)

Contains at least one selected from Si, Mn and A1 in an amount that satisfies the following formula (3) I do.

0.1 wt% ≤3Αί + 2S i + Mn≤50wt% · (3)

Contains the amount satisfying (4). ⁵ 0.001% by weight ≤ 4Ca + 4Mg + REM ≤ 0.2% by weight ············································································································································ Is omitted.

[C] Category C invention

Hereinafter, the present invention will be described in more detail.

(I) First, the Fe-Cr alloy of the present invention having excellent workability and pitting resistance will be described.

Figure 18 shows the effect of N, 0, P on the change in elongation and the change in yield strength obtained by the tensile test specified in JISZ-2241 for the cold-rolled annealed sheet of Fe-18% Cr alloy. The effect of the total amount of C, N, 0, P, and S is shown below, but it is clear that when the total amount of C, N, 0, P, and S is less than 10 ppm, the ductility is remarkably excellent, and the YS is also low, resulting in softening.

In Fig. 18, the change in elongation (%) and the change in heat resistance (yield strength) (N / f ² ) were calculated for each alloy component using the tensile test with C + N + 0 + S + P = 50 Oppm. It shows the difference in characteristics.

The basic tensile properties are as follows.

Fe-18Cr, C + N + O + S + P = 500ppm elongation of 30%,耐Ka 330N / land ² Fe- 30Cr, 25% elongation at C + N + O + S + P = 500ppm,耐Ka 450 N / Thigh ² Figure 19 shows the M0 content and pitting potential for cold rolled annealed sheets of Fe 16% Cr alloy with a total content of C, N, 0, P and S of 100 ppm or less. (Measured in accordance with JISG 0577). It is clear that when the Mo content is 0.5% by weight or more, the pitting potential is remarkably improved and the pitting resistance is excellent.

Next, the composition of the alloy of the present invention will be described.

Cr: 5 to 60% by weight, preferably 10 to 40% by weight. When the Cr content is in this range, the corrosion resistance is excellent. Excessive Cr content improves corrosion resistance Saturates and lacks economic rationality, even if (S + P + 0 + N + C) ≤

Even if it is 10 Oppm, it is not preferable because the workability is easily reduced by solid solution strengthening of Cr itself.

C, N, 0, P, S: The total ff * of these elements is 10 Oppm or less. As described above, when it is 100 ppm or less, excellent ductility is exhibited, and workability is excellent.

Mo: 0.5 to 20% by weight, preferably 0.5 to 5% by weight. 0.5

Any of the above is excellent in predation, but an excessive content is uneconomical and is not preferable.

Fe—Cr alloys that satisfy the above conditions have excellent workability and excellent pitting resistance.

(II) Next, the Fe-Cr alloy of the present invention having excellent workability, pitting corrosion resistance and acid resistance will be described.

FIG. 20 shows that the total amount of C, N, 0, P and S is 10 Oppm or less,

Corrosion rate of Fe-16% Cr alloy plate in 0.3wt HC1 aqueous solution and (Ni +

(Co + 2Cu)% by weight. From this graph, (Ni + Co +

It is clear that when the value of (2Cu) is 0.01% by weight or more, the corrosion rate is reduced and the acid resistance is improved.

Regarding the contents of Cr, C, N, 0, P, S, and Mo, the description in (I) is applied as it is. The alloy according to the embodiment (II) further contains at least one of Ni, Cu, and Co, and the content satisfies the following formula (1), preferably the formula (1a), whereby the acid resistance is improved. This is an excellent alloy. 0.01% by weight ≤ Ni + Co + 2Cu ≤ 6% by weight …… (1)

0.1 wt% ≤Ni + Co + 2Cu≤4 wt% (la)

Excessive blending of Ni, Co, and Cu beyond the formula (1) is not preferable because these elements are austenitic stabilizing elements, which cause inconvenience to finally obtain a ferrite single phase structure.

The alloy of the embodiment (II) which satisfies the above conditions is excellent in workability and extremely excellent in pitting corrosion resistance and acid resistance.

To produce the Fe—Cr alloys described in (I) and (II) of the present invention, first, high-purity electrolytic iron, electrolytic Cr, metallic Mo, electrolytic Ni, electrolytic Cu, and metallic Co are used as raw materials. Any of raw materials major impurity is oxygen, can be prepared Fe one C r alloy of the present invention 10_ ⁷ t 0 rr higher dissolved under ultra-high vacuum in order to remove the oxygen, by铸造.

In addition, it goes without saying that the alloy of the present invention can obtain its effects in hot-rolled and cold-rolled annealed sheets. In addition, BA, 2B, 2D, HL, polishing, etc., are sufficient for final surface finish.

(III) Further, the Fe—Cr alloy of the present invention, which is excellent in workability, corrosion resistance and oxidation resistance, will be described.

FIG. 21 is a graph showing the results of an oxidation resistance test (weight reduction after removing the scale at 1350 K in the atmosphere for 12 hours) for a Fe— (15 to 30)% Cr alloy.

When (3A1 + 2Si + Mn) is 0.1% by weight or more, it is clear that the composition has excellent oxidation resistance.

Figure 22 shows the oxidation resistance test (atmosphere) for the Fe— (15-30)% Cr alloy. 9 is a graph showing the results of the weight reduction after removing the scale at 1350 K for 12 hr. It is clear that when (4Ca + 4Mg + REM) is 0.001% by weight or more, the oxidation resistance is excellent.

Hereinafter, the alloy and the embodiment of the present invention will be described. The Fe—Cr alloy having excellent workability, pitting corrosion resistance, and oxidation resistance according to the present invention has the following three aspects, each of which will be described.

(1) First embodiment of the present invention

Cr: 5 to 60% by weight, preferably 5 to 45% by weight. If the content is within the above range, the alloy is combined with the other conditions of the present invention to provide an alloy having excellent oxidizing properties. However, an excessive content exceeding 60% by weight is not preferable because the cost increases.

C, N, 0, P, S; the total amount of these elements is 10 Oppm or less, preferably 85 ppm or less. Under these conditions, the ductility, that is, the workability of the alloy is improved, and at the same time, it is combined with the condition of the Cr content specified above, and the oxidation resistance is excellent. When the total amount exceeds 100 ppm, such an excellent effect is not exhibited.

The Mo: Mo content is between 0.5 and 20% by weight, preferably between 0.5 and 5% by weight. When Mo is contained in the alloy in this range, the pitting corrosion resistance is improved. Excessive content exceeding _σ 20% by weight is not preferable because it increases the cost.

Al, Si, Mn: Contain one or more of these 5%

(2), preferably, is added so as to satisfy (2a).

0.1% by weight ≤3Al + 2Si + Mn≤50% by weight ■ (2)

0.3% by weight 3A1 + 2S i + Mn ≤30% by weight (2a) By containing these elements in the above range, the oxidation resistance is remarkably improved. However If the amount of 3A1 + 2Si + Mn exceeds 50% by weight while adding excessively, workability deteriorates, which is not preferable.

The preferred content of each of Al, Si and Mn is as follows.

A 1: 0. 4% by weight

S i: 0.3-3% by weight

Mn: 0.5 to 10% by weight

(2) Second embodiment of the present invention

Regarding the Cr content, the contents of C, N, 0, P and S, and the content of Mo, the description in the first embodiment also applies in this embodiment.

In the alloy of the second embodiment, at least one selected from Ca, Mg and REM is contained.

Ca, Mg, REM: When these elements are contained in the alloy of the present invention so as to satisfy the following formula (3), the oxidation resistance is further improved, and a favorable result is obtained.

0.001% by weight ≦ 4 Ca + 4Mg + REM ≦ 0.2% by weight (3) The preferable contents of each of Ca, Mg and RE1V are as follows.

Ca: 0.0002-0.03% by weight

Mg: 0.0003-0.03% by weight

REM: 0.0005 to 0.15% by weight

The alloy of the present invention described in (II), which satisfies the above conditions, is excellent in workability, and is excellent in pitting corrosion resistance and oxidation resistance, and thus is suitable for applications such as automobile exhaust pipes. In order to produce the Fe-Cr alloy of the present invention, first, ultrahigh-purity electrolytic iron and electrolytic Cr are used as raw materials.

Both main impurities of the raw material is oxygen, the dissolved oxygen at a high ultra high vacuum than 10 one ⁷ torr to remove, is possible to produce F e-Cr alloy of the present invention by Kagizo it can.

(3) Third embodiment of the present invention

An alloy that satisfies both the conditions of the alloy of the first embodiment and the conditions of the alloy of the second embodiment described above, that is, the Cr content is 5 to 60 Efi%, C, N, 0, P, and so on. And the total amount of S is less than or equal to 1 O.Opm, the M0 content is 0.5 to 20% by weight, and one or more types selected from Si, Mn and A1 are represented by the formula (2) ), And furthermore, Fe-Cr alloys containing at least one element selected from Ca, Mg and rare earth elements (REM) in an amount satisfying the formula (3) are also more excellent in oxidation resistance. It is an alloy having properties and workability, and is preferably used for the above-mentioned applications.

In order to produce the Fe-Cr alloy of the present invention including these three embodiments, as raw materials, ultra-high-purity electrolytic iron, electrolytic chromium, zone melt silicon, molten salt electrolytic manganese, molten salt electrolytic aluminum, Use electrolytic salt of molten salt, electrolytically reduced magnesium, or electrolytically reduced rare earth metal. Les, the raw material of the displacement also major impurity is oxygen, dissolved at a high ultra-high vacuum than 10- ⁵ 1 orr to remove this oxygen, the F e-Cr alloy of the present invention by a child縴造Can be manufactured.

(IV) Finally, the Fe—Cr alloy of the present invention, which is excellent in acid resistance and oxidation resistance in addition to workability and pitting corrosion resistance, will be described.

The alloy according to the present invention has an excellent acid resistance in addition to the alloy composition described in (II). In addition, the alloy composition having excellent oxidation resistance as described in (III) is taken into account. Therefore, only the mode is shown below, and the detailed description is omitted because it is as described in (II) and (III).

> 'There are three aspects of this invention, as in the invention of (III), C + N + 0 + P≤i 100 ppm, Cr: 5 to 60% by weight, Mo: 0.5 2020% by weight, and in addition to 0.01% ≤] ^ 1 + (0 + 2 (13≤6%), only the changed portions will be described below for each embodiment.

(1) First embodiment of the present invention

0.01% by weight ≤Ni + Co + 2Cu≤6% by weight …… (1)

At least one selected from Si, Mn and A1 is contained in an amount satisfying the following formula (2).

0.1 weight 3 A 1 +2 S i + Mn ≤ 50% by weight …… (2)

(2) Second embodiment of the present invention

0.01% by weight ≤Ni + Co + 2Cu≤6% by weight …… (1)

At least one selected from the group consisting of, Ca, Mg and rare earth elements (REM)

(3) is contained.

0.00% \ 4 ≤ 4 Ca + 4 Mg + REM ≤ 0.2% by weight (3) (3) Third embodiment of the present invention At least one selected from Ni, Co and Cii is contained in an amount satisfying the following formula (1).

0.0 1% by weight ≤N i + Co + 2 Cu≤ & weight ¾ …… (1)

Contains at least one selected from Si, Mn and AI in an amount satisfying the following formula (2).

0.1 weight 3 A 1 +2 S i + Mn ≤ 50% by weight (2)

At least one selected from Ca, Mg and rare earth elements (REM) is contained in an amount sufficient to satisfy the following formula (3).

0.001M% ≤Ca + 4Mg + REM≤0.2M% (3) Since the method of manufacturing the alloy of the present invention is exactly the same as above, detailed description is omitted.

CD] Category D Invention

Hereinafter, the present invention will be described in more detail.

(I) First, a Fe-Cr alloy with excellent workability, pitting corrosion resistance and weld corrosion will be described.

Figure 23 shows the results of tensile tests at room temperature and the total amount of C, N, 0, P and S for Fe-18% Cr alloy, based on the conventional alloy with the above total amount of about 50 ppm. , It is shown. It can be seen that when the content is 10 O ppm or less as compared with the conventional alloy, the elongation value is increased, the P-Yield strength is remarkably reduced, and the ductility is significantly improved.

In addition, the preparation method and measurement method of a test piece are as follows.

Specimen: Melted and fabricated in a vacuum furnace at 10 k £, hot rolled to 4 mm thickness, recrystallized and annealed, descaled, cold rolled to 0.8 mm thick, recrystallized and annealed Wood.

Measurement method: Evaluated by a tensile test according to JISZ-2241. Specimens were sampled from the L, X, and C directions and calculated by (L + C + 2XX) Z4. In Figure 23, the change in elongation (), a change in耐Ka (yield strength) and (N / Yuzuru ²⁾ for each alloy component, the tensile and that of C + N + 0 + S + P = 500 ppm properties Indicates the difference between

The basic tensile properties are as follows.

Fe-18Cr, 30% elongation at C + N + 0 + S + P = 500 ppm, power resistance 33 ON / country ² Fe-- 30 Cr, 25% elongation at C + N + 0 + S + P = 500 ppm ,耐Ka 450 is N / mm ² Fig. 24, C, N, 〇, the total amount of P and S 1 0 0 p pm following F e (1) The relationship between the Mo content and the pitting potential was shown for the cold rolled 1 &% Cr alloy sheet. When the Mo content was 0.5% by weight or more, the pitting potential rapidly increased, and the pitting resistance increased. It is clear that the food is excellent.

Specimen: melted in a 10 kg vacuum furnace, key-formed, hot rolled to a thickness of 4 mm, then reconstituted

1 After annealing, descaling, and cold rolling to 0.8 mm thickness, recrystallization annealing was performed, and the surface was polished with # 1 800 to obtain a test piece.

Measurement Anode polarization curve was determined in a 100 Oppm C I "solution according to JIS G 0577, and Vc 10 A was defined as the pitting potential.

FIG. 25 shows the results of the intergranular corrosion test of the TIG weld for the Fe-2OCr alloy in which the total amount of C, N, 0, P and S is 100 ppm or less, (T i + Nb + Zr + V + Ta + W + 5 OxB) values are shown when the weight is changed. According to this, if the above value is 0.01% or more, the corrosion resistance of the weld zone is remarkable (intergranular corrosion resistance). ) Is clearly improved.

Specimen: Melted in a 10 kg vacuum furnace, keyed, hot rolled to a thickness of 4 mm, recrystallized, burned, descaled, cold rolled to a thickness of 0.8 mm, recrystallized, and resurfaced A # 500 polished sample was subjected to TIG welding (bead-on) to obtain 烘 test material.

Measurement method Evaluation was made based on the presence or absence of cracks in the weld bending test (r = 2 t, 180. C bending) after the copper sulfate monosulfate test in accordance with J IS G-0572. -Figure 26 shows that the total amount of C, N, 0, P and S is less than 10 Oppm, The relationship between the corrosion rate obtained by an immersion test of a Fe— (25-45)% Cr alloy plate in a 5 wt% HC1 aqueous solution and (Ni + Co + 2Cu) wt% was shown. From this graph, it is clear that when the value of (Ni + Co + 2Cu) exceeds 0.01% by weight, the corrosion rate sharply decreases and the acid resistance improves.

The preparation method and measurement method of the test piece are as follows.

Specimen: Melted and forged in a 10 kg vacuum furnace, hot rolled to 4 mm thickness, recrystallized and annealed, descaled, cold rolled to 0.8 mm thick, recrystallized and annealed, Mary # 500 was polished and used as a test piece.

Next, the composition of the alloy of the present invention will be described.

Cr: 5 to 60% by weight, preferably 10 to 35% by weight. When the Cr content is within this range, the corrosion resistance of the alloy is excellent. Excess of more than 60% by weight of Cr is not preferred because the effect of improving corrosion resistance is almost saturated and becomes economically unreasonable, as well as lowering workability.

C, N, 0, P, S: The total amount of these elements is 100 ppm or less. As described above, when it is 100 ppm or less, excellent ductility is exhibited, and workability is excellent.

Mo: 0.5 to 20% by weight, preferably 1 to 10% by weight. If the content is 0.5% by weight or more, the pitting resistance is excellent, but an excessive content is uneconomical and not preferable.

Ti, Nb, Zr, V, Ta, W, B: The alloy of the present invention contains one or more of these elements, and the content satisfies the following formula (1). It is preferable to satisfy the expression (1a). 0.0 1% by weight ≤ Ti + Nb + Zr + V + Ta + W + 50 B ≤ 1.0% by weight

……… (1)

0.05 fi *% ≤T i + Nb + Z r + V + T a + W + 50 B≤ 0.5 wt%

... (l a) By satisfying this formula, an alloy of the present invention having extremely excellent weld corrosion resistance (intergranular corrosion resistance) can be obtained. However, excessive inclusion of these elements is not preferable because workability is reduced by solid solution strengthening of the added elements themselves.

Further, the contents of Ti, Nb, Zr, V, Ta, W or B are preferably within the following ranges.

Ti: Ti≤5 C% + N%)

Nb: 0.01 to 5% by weight

Zr: 0.0% 0.5% by weight

V: 0.01 to 0.5% by weight

Ta: 0.5% by weight 0.5% by weight

W: 0, 0.5 weight

B: 0.0003-0.01 double

Fe—Cr alloys that satisfy the above conditions have excellent workability, and are also excellent in pitting corrosion resistance and corrosion resistance at welds (intergranular corrosion resistance), including water heater cans and automotive muffler materials. It can be preferably used for various applications.

(1 [) Next, the Fe—Cr alloy of the present invention, which is excellent in workability, pitting corrosion resistance, weld corrosion, and acid resistance, will be described.

In addition to the above condition (I), at least one of Ni, Cu and Co When the alloy has the following content (2), the alloy has excellent acid resistance. Preferably, (2a) is satisfied.

0.0 i &% ≤Ni + Co + 2 Cu≤ 6E *% (2)

0.05% by weight ≤ Ni + Co + 2Cu ≤ 5% by weight (2a)

Excessive blending of Ni, Co, and Cu beyond equation (2) means that these elements are austenitic stabilizing elements, and a large amount of C is necessary to finally obtain a ferrite single phase as in the present invention. Undesirably, addition of r and Mo is required.

Ni: 0.05 to 5.0% by weight

Co: 0.05-5.0% by weight

Cu: 0.05 to 2.5% by weight

Alloys that satisfy the conditions described in (I) or (II) above have excellent workability, and are remarkably excellent in pitting corrosion resistance, corrosion resistance at welds (intergranular corrosion resistance), and acid resistance. It is suitable for various uses including muffler materials, water heater cans, and materials for chemical plants.

In order to produce the Fe—Cr alloy described in (I) or (II) of the present invention, first, high-purity electrolytic iron, electrolytic Cr, metal Mo, metal Ti, metal Nb, gold Genus Zr, metal V, metal Ta, metal W, high purity (F e -B), electrolytic Ni, electrolytic Cu and metal Co are used. The main impurity in all raw materials is oxygen. To remove this oxygen, the Fe-Cr alloy of the present invention is manufactured by melting and manufacturing under an ultrahigh vacuum of 10 t0 rr or more. be able to. (Ii) In addition, the Fe-Cr alloy of the present invention, which is excellent in workability, pitting corrosion resistance, weld corrosion resistance and oxidation resistance, will be described.

Figure 27 shows the oxidation resistance test (1350 K in air: 1350 K: after removing the scale for 12 hours) for a Fe— (15-30)% Cr alloy whose total amount of C, N, 0, P and S is 10 Oppm or less. 4 is a graph showing the results of (weight loss). It is clear that (3A1 + 2Si + Mn) has excellent oxidation resistance when it is 0.1% by weight or more.

Figure 28 shows the oxidation resistance test (1350K in air, 12hr scale) for Fe— (15-30)% Gr alloy with the total amount of C, N, 0, P and S being less than 10 Oppm. 4 is a graph showing the results of the following (weight loss after removal). It is clear that (4Ca + 4Mg + REM) is excellent in oxidation resistance when it is more than 0.01% by weight. Hereinafter, components and embodiments of the alloy composition of the present invention will be described. The Fe—Cr alloy having excellent workability and oxidation resistance according to the present invention has the following three embodiments, each of which will be described.

(1) First embodiment of the present invention

Cr: 5 to 60% by weight, preferably 10 to 40% by weight. When the Cr content is in this range, the alloy is combined with other conditions to provide an alloy having excellent oxidation resistance. Excessive Cr content is not preferable because it causes a reduction in workability and saturates the effect of improving oxidation resistance.

C, N, 0, P, S: The total amount of these elements is 10 ppm or less, preferably 85 ppm or less. Abnormal oxidation is suppressed by fulfilling this condition. Then, when these conditions are combined with other conditions, an alloy having excellent oxidation resistance is obtained, and at the same time, an alloy having excellent ductility and good workability is obtained. Mo: 0.5 to 20% by weight, preferably 1 to 10% by weight. When the weight is 0.5 weight or more, the pitting resistance is excellent, but the excessive content is uneconomical and not preferable.

Ti, Nb, Zr, V, Ta, W, B: The alloy of the present invention contains one or more of these elements, and the content satisfies the following formula (1). Preferably, (1a) is satisfied.

0.01% by weight ≤ Ti + Nb + Zr + V + Ta + W + 50 B ≤ 1.0% by weight

(1)

0.05M% ≤Ti + Nb + Zr + V + Ta + W + 50B≤0.5wt%

(1a) By satisfying this formula, an alloy of the present invention having extremely excellent weld corrosion resistance (intergranular corrosion resistance) can be obtained. However, excessive inclusion of these elements is not preferable because workability is reduced by solid solution strengthening of the added elements themselves.

Si, Mn, A1: The alloy of this embodiment contains one or more of these elements, and the content satisfies the following formula (3), preferably (3a).

0.1 weight 3 A 1 +2 S i + Mn ≤ 50 weight …… (3)

0.5 weight 3 A 1 +2 S i + Mn ≤ 25% by weight …… (3 a) By being in such a range, it is combined with other conditions, and the alloy is remarkably excellent in oxidation resistance. Becomes By adding these elements in excess, 3 A 1 + 2S i + Mn If the value exceeds the range of the equation (3), it becomes difficult to produce an alloy, so that excessive contents of these elements should be avoided.

S i: 0.1 to 10.0%

Less than 0.1 weight is effective but not significant. If it exceeds 10.0% by weight, the decrease in productivity becomes noticeable.

Μη: 0. 5.0% by weight

A1: Hi. 1 ~ 4.0 dragon%

0.1% by weight not grooved is effective but not significant. If the weight is more than 10.0, the manufacturability may decrease.

Since the Fe-Cr alloy that satisfies the above conditions has excellent oxidation resistance and workability, it can be appropriately used for automobile exhaust gas system members, pipes used in a high-temperature repeated oxidation environment, and the like.

(2) Second embodiment of the present invention

Regarding the Cr content, the contents of C, N, 0, P and S, and the preferable content of Fe, the description in the first embodiment also applies in this embodiment.

In the alloy of the second embodiment, at least one selected from Ca, Mg and REM is contained. The content of these elements is determined by the following formula (4), preferably

(4a) is satisfied.

0.001SM% ≤4 Ca + 4Mg + REM≤ 0.2% by weight (4) 0.005% by weight ≤4 Ca + 4Mg + REM ≤ 0.15% by weight (4a) By satisfying this condition, it is combined with other conditions to provide excellent oxidation resistance and An Fe-Cr alloy with good workability can be obtained.

However, if these elements are excessively contained and the value of (4Ca + 4Mg + REM) exceeds 0.2% by weight, surface defects of the alloy are likely to occur, which is not preferable.

Ca: 0.002-0.0 1% by weight

Less than 0.002% by weight is effective but not significant. If the content exceeds 0.01% by weight, the decrease in productivity becomes noticeable.

Mg: 0.002 to 0.0 1% by weight

REM: 0.005 to 0.1% by weight

Even if less than 0.005% by weight is effective, it is not remarkable. If the content exceeds 0.1% by weight, the effect will be saturated and the cost will increase.

Such an alloy of the second embodiment of the present invention can be used for the same applications as the alloy of the first embodiment. (3) Third embodiment of the present invention

An alloy that satisfies both the conditions of the alloy according to the first embodiment and the conditions of the alloy according to the second embodiment of the present invention described above, that is, a Cr content of 5 to 60% by weight, C, N, 0, The total amount of P and S is 1 ppm or less, the content of M is 0.5 to 20% by weight, and Ti, Nb, Z, V, Ta, W and B are selected. At least one kind is contained in an amount satisfying the formula (1), and at least one kind selected from Si, Mn and A1 is contained in an amount satisfying the formula (2), and Ca, Mg and A Fe—Cr alloy containing one or more selected from rare earth elements (REM) in an amount satisfying the above formula (3) is also an alloy having more excellent oxidation resistance and workability, and is preferably used for the above application. Used.

In order to produce the Fe—Cr alloy of the present invention including these three embodiments, ultrahigh-purity electrolytic iron, electrolytic chromium, zone melt silicon, molten salt electrolytic manganese, molten salt electrolytic aluminum are used as raw materials. Use molten salt electrolytic calcium, electrolytic reduced magnesium, electrolytic reduced rare earth metal. Les, the raw material of the displacement also major impurity is oxygen, dissolved high under ultrahigh vacuum than 10 _ ⁵ 1 ₀ rr to remove this oxygen, F e- C r of the present invention by Kagizo Alloys can be manufactured.

(IV) Finally, the Fe-Cr alloy of the present invention which is excellent in acid resistance and oxidation resistance in addition to workability, pitting corrosion resistance and welded portion corrosion resistance will be described.

This alloy of the present invention is obtained by taking into account, in addition to the alloy composition particularly excellent in acid resistance described in (II), the alloy composition particularly excellent in oxidation resistance described in (III). Therefore, only the mode is shown below, and the detailed description is omitted because it is as described in (II) and (III). This invention has three embodiments similar to the invention of (III), C + N + 0 + P≤100 ppm, Cr: 5 to 60% by weight, Mo: 0.5 to 20% by weight. Yes, 0.0 l% ≤Ti + Nb + Zr + V + W + 50B≤1%, and only the parts that change are described below for each embodiment.

(1) First embodiment of the present invention

Contains at least one selected from Ni, Co and Cu in an amount that satisfies the following formula (2).

0.01 weight ^ Ni + Co + 2Cu≤6wt% (2)

At least one selected from S i, Mn and A 1 is contained in an amount satisfying the following formula (3).

0.1 weight ^ 3 A 1 + 2S i + Mn ≤ 50% by weight (3) Preferably,

0.5 weight 3 A 1 +2 S i + Mn ≤ 25% by weight ······· (3 a)

(2) Second embodiment of the present invention

0.01 weight ^ Ni + Co + 2Cu≤6 weight (2)

At least one selected from Ca, Mg and rare earth elements (REM) is contained in an amount satisfying the following formula (4).

0. Hi 01 wt% ≤ 4 Ca + 4 Mg + REM ≤ 0.2 wt …… (4) Preferably,

0.005% by weight ≤ 4Ca + 4Mg + REM ≤ 0.15% by weight ...... (4a) (3) Third embodiment of the present invention

0.0 mS% ≤ i + Co + 2Cu≤6Sfi% (2)

At least one selected from Si, Mn and A1 is contained in an amount satisfying the following formula (3).

0.1 Ά% ≤ 3 A 1 + 2 S i + Mn≤ 50 &% (3) Preferably,

0.5% by weight ≤3A1 + 2S i + Mn≤25% by weight. · (3 a)

One or more selected from Ca, Mg and rare earth elements (REM)

Contains the amount satisfying (4).

0.001 weight ^ 4Ca + 4Mg + REM≤0.2 weight ............ (4) Preferably,

0.005% by weight≤4Ca + 4Mg + REM 0.15fiS¼ -... (4a) Since the manufacturing method of the alloy of the present invention is exactly the same as above, the detailed description is omitted.

Example

[A] Category A invention

Hereinafter, the present invention will be described more specifically with reference to examples.

(Example 1)… corresponding to invention alloys 1 to 13 and comparative alloys 1 to 12… corresponding to claim 1 10 kg of an alloy having the chemical composition shown in Table 1 was melt-produced in a vacuum melting furnace and heated. A hot-rolled sheet with a thickness of 4 mm is formed by cold rolling, subjected to hot-rolled sheet annealing for recrystallization, descaled, and then cold-rolled into a 0.7-mm-thick cold-rolled sheet. Then, recrystallization annealing was performed to obtain a cold-rolled annealed sheet.

Using the thus obtained cold-rolled annealed sheet, the elongation value was determined by a tensile test in accordance with JIS Z-2241, and after cold rolling of 50%, the value was 180 in the C direction. Table 2 shows the state of cracking when the contact bending test was performed.

Note elongation were L direction, X direction, the average elongation _{(E 1 L + E 1 c} + 2 XE lx) Z 4 in the direction C shown in Table 2. The bending property was evaluated as follows. 〇 ······· No cracking

△ ... '"... micro crack

Large crack

In addition, changes in elongation and changes in power (yield strength) of the test materials obtained in all examples were examined.

Change in elongation (%), and the耐Ka change in (Fujo strength) (N / discussions ²⁾ For each alloy component, C + N + 0 + S + P = 5 0 0 ppm ones and tensile The difference in characteristics is shown. The basic tensile properties are as follows. F e-18Cr, C + N + O + S + P = 500 ppm, elongation, resistance 330 N / marauding ² F e- 30 Cr, C + N + O + S + P = 500 ppm, elongation 25%, resistance F 450N / ² C, N, 0, P, and S, which are well known as impurities, are reduced to a total of 10 Oppm or less, so that the C direction after 50% cold rolling regardless of the amount of Cr It can be seen that cracking did not occur even in the adhesion bending test and that it had excellent workability. On the other hand, when the above amount is more than 10 ppm and less than 200 ppm, constant Cr alloy micro cracks occur (Comparative alloys 1, 2, 3, and 4). When the content exceeds 10 ppm, large cracks occur (specific alloys 5, 6, 7, 8, and 9), indicating that the additivity decreases.

—On the other hand, when the same Cr content is compared, it is found that the elongation is remarkably improved by setting the total I of C, N, 0, P and S to 10 Oppm or less.

The composition of Fe—11% by weight Cr—0.003% S i—0.005% n-0, 007% Table 2 shows the degree of rusting after a salt water spray test (24 hr) using 5% NaC1 at 50 at 5% NaC1 on the alloy plate with the total amount varied in various ways. (Score A: no rust, B: slight rust, C: small rust, D: large rust) o

It can be seen that by setting the total amount of C, N, 0, P and S to 10 Oppm or less, the rust resistance is remarkably improved and no rust is generated.

(Example 2) ... corresponding to invention alloys 14 to 20 and comparative alloys 13 and 14 ... corresponding to claim 2-A 100 kg high frequency induction heating ultra-high vacuum smelting furnace was used for the test materials having the component ranges shown in Table I. hand Produced. These test materials were forged, cut and hot rolled, then annealed and cold rolled to produce 1. Omm thick steel sheets.

Then, lmm ¹ X 5 Ommx 50mm test pieces were made from these materials,

① Immersion test at 40 ° C for 24 hours in 5% HC1

_{_{② 4% H 2 S0 4,}} 50 ° C, 24 hours immersion test

The corrosion rate (g / m ² 'hr) was measured. The results are summarized in Table 2. From the results in Table 2, it is clear that the corrosion in the acid immersion test is significantly suppressed in the component range of the present invention as compared with the material in the component range of the comparative example. In addition, for a material in which the total of C, N, 0, P and S is 10 Oppm or less, the effect is remarkable when Co + Ni + 2Cu is 0.01% or more.

From these results, it was found that the total content of C, N, 0, P, and S in Fe-Cr (5≤Cr60) alloy was 100 ppm or less, and Ca, Ni, 〇0 It is clear that an alloy having excellent acid resistance can be obtained by including one or more of the above in the range of 0.01% by weight ≤ {0 + 1 ^ + 2 11 ≤ 6% by weight.

(Example 3-1) ... corresponds to invention alloys 21 to 33, comparative alloys 15 to 18 ... corresponds to claim 3.

Test materials with the components shown in Table 1 were produced in a 100 kg high-frequency induction heating ultra-high vacuum melting furnace. These test materials were forged, cut, and hot-rolled, and then repeatedly sintered and cold-rolled to produce a foil strip having a thickness of 50 fim and a width of 20 Omm.

Thereafter, a continuous oxidation test and a repeated heating test were performed on the foil strip test pieces (5 O ^ rn 'x 5 Omm x 5 Omm) made from these materials by the following methods. Was. Table 2 shows the results.

(1) Oxidation test

After exposing the specimen to the atmosphere at 1150 for 300 hours, the abnormal oxidation area was measured. The evaluation was performed as follows.

◎ Abnormal oxidation surface zero

〇 Abnormal oxidation area within 5%

Abnormally oxidized area 5-20%

Unusual oxidation area 20-40%

Abnormal oxidation area 40% or more

(2) Repeated heating test

In the atmosphere, the test piece was repeatedly heated 1 time at 150 ° C for 30 minutes and then left to cool for 30 minutes 50 times, and then the separated area of the oxide film on the test piece was measured. The evaluation was performed as follows.

◎ Zero abnormal oxidation area

〇 Abnormal oxidation area within 10%

Δ abnormal oxidation surface ft 10-30

-Abnormal oxidation area 3 ~ 50%

X X Abnormal oxidation area 5% or more

In the component range of the present invention, the occurrence of abnormal oxidation was suppressed as compared with the component range of the comparative example, and the component range was covered with an oxide film having a sound and excellent adhesion. On the other hand, the oxide film of the comparative alloy showed poor adhesion and abnormal oxidation. For materials with a total of C, N, 0, P and S less than 1 and 0 ppm, 3 A 1 +2 S i + Mn However, the effect was remarkable at 0.1% or more. From these results, the total of S, P, 0, N, and C is less than 10 ppm in Fe-Cr (3≤Cr≤60) alloy, and 1 out of Si, Al, and Mn. It is clear that adding Fe or two or more species in the range of 0.1 wt. 3 A 1 +2 S i + Mn ≤ 50 wt.% Gives a Fe-Cr alloy with excellent oxidation resistance. .

In addition, by adding one or more of Ca, Mg, and REM to the above components in the range of 0.001% by weight ≤ 4 Ca + 4 g + REM ≤ 0.2% by weight, Fe- It is clear that a Cr alloy is obtained.

(Example 3-2) ... corresponding to invention alloys 34 to 41 and comparative alloys 19 and 20 ... Claim 3

Specimens with the component ranges shown in Table 1 were prepared using a 100 kg high-frequency induction heating ultra-vacuum smelting furnace.These specimens were forged, cut, hot-rolled, and then annealed and cold-rolled. The process was repeated to produce a foil strip with a thickness of 50 m and a width of 200 m.

A continuous oxidation test and a repeated heating test were performed in the same manner as in Example 3-1 except that the temperature of the foil strip test piece (50 m 'X 5 Omm x 5 Omm) made from these materials was set to 1100 ° C. . The results are summarized in Table 2.

The evaluation of each test is as follows.

(1) Continuous oxidation test

〇 Abnormal oxidation area 5% or less

△ Abnormal oxidation area 5-20%

X Abnormal oxidation area 20% or more (2) Repeated heating test

〇 Abnormal oxidation area 10% or less

△ Abnormal oxidized surface 10 ~ 3%

X Abnormal oxidation area 30% or more

Compared to the material of the comparative alloy, the composition range of the alloy according to the present invention does not cause abnormal oxidation and is covered with a sound and highly adherent oxide film. Gold oxide film showed poor adhesion and showed abnormal oxidation.

From these results, it was found that Fe, Cr (3≤Cr≤60) alloy, S, P, 0, N, and C were 100 ppmJK in total and Ca, Mg :, and REM were one or more types. It is clear that an alloy having excellent oxidation resistance can be obtained by setting 0.001 ≦ 4Ca + 4Mg + REM ≦ 0.2.

(Example 4) ... corresponding to invention alloys 42 to 44 and comparative alloy 21 ... corresponding to claim 4 The test materials having the components shown in Table 1 were produced using a 100 kg high-frequency induction heating ultra-vacuum melting furnace. After forging, cutting, and hot rolling these test materials, annealing and cold rolling were repeated to produce a foil strip having a thickness of 50 jm and a width of 200 j / m.

For the obtained test material, the same as in the above example: (1) 5% HC 1,40. C corrosion _{rate, ② 40% H 2 S O4} , 50. C corrosion degree, ③ continuous oxidation test, ④ repeated heating test, evaluated in the same way, and the results are shown in Table 2.

It is clearly shown that those falling within the scope of the present invention exhibit excellent properties. Table 1 (Part 1)

Unit:%, * mark ppm

= C + N + 0 + S + P,

+ 2Cu, r = 3 A 1 + 2S i + Mn, 5 = 4 Ca + 4Mg + REM

Table 1 (Part 2)

Light

Combination

Neat

Unit: »%, * mark pp m

a = C + N + 0 + S + P, β- = Ni + Co + 2Cu, r = 3Al + 2S i + Mn, 5 = Ca + 4 g + REM

Table 1 (Part 3)

Unit:%, 氺 mark ppm

a = C + N + 0 + S + P, 3 = Ni + Co + 2Cu, r = 3 A 1 +2 S i + Mn, 5: 4Ca + 4Mg + RE

Table 1 (Part 4)

Unit:%, * mark ppm

Ca + 4 g + REM

Table 1 (Part 5)

Ratio

Comparison

Combination

Unit 氺 mark ppm

a = C + N + 0 + S + P, S = Ni + Co + 2Cu, r = 3 A 1 + 2S i + Mn, 5: 4Ca + 4Mg + REM

£ 66dd§6 OAV:

■■ 9 'uH + i SZ + IVe = ^' n02 + oo +! N = 'd + S + O + N + 0 = »zoo'o: i¾a'sooo'o: aiK

Π \ \ "b V U b rol ¾nno'ft: Bi'i" τ: ιη ι 1τ 1 Ό υ Λ'Τ 1 Ι IΛV'Λli \ / V ι fi 0T1 οό τ 1ρο 0076 lo

8000 Ό εοΌ Ϊ6Ι Ζ0000: 3Η 10 Ό 10 Ό Ζ00Ό 10 ~ Ύ ζ \ 01 99 19 02

WT0 90 Ό W Ϊ0Ό: ¾¾ Ζ0Ό ΖΟ'Ο 200 Ό 10 Ό 0 * 91 8Ϊ 21 εε 08 19 61

W0 SO 一 w Γ0 SO'O ΪΌ ΖΟ'Ο 8Ϊ ι \ 91 8Ζ ζ 19 8Ϊ

80 Ό W εοΌ Ϊ0Ό 10 Ό ΪΟΌ 02 ει Ζ \ εε 82 19 L \ ί'Ο m 2Ό ΓΟ ΓΟ 10 Ό ~ Τ 03 91 08 9 & 91

6ε W 8Ό 20 · 0 ΟΊ 10 Ό 91 SI 2,1 νζ 22 OS 9Ϊ

SOO'O W 900 Ό οο Τ0Ό Ζ0Ό ΪΟΟΌ ΖΟΌ 81 η 01 09 12 91

0'g ιεΓ ΖΟ'Ο ΖΟ'Ο ΪΟΟΌ 10 * 0 \ ζ 21 92 ιζ 19 ει

& IS IV O • 13 .d, 0, Ν .0

Table 2 (Part 1)

Change Elongation pressurized E brine injection changes strength of NakaBi _{5¾HC1. 40 * C 40¾H 2 S0} 4 .50 e C鹏酸of repeated heating (%) (N / mn :) (%) bendability point Kusa倾(g / m ² , hr) Corrosion rate (g / m ² .hr), test

1 + 7.1-1 0 6 4 6 〇

2 + 6. 9-1 0 3 4 1 〇

Departure 3 + 5.3-1 0 3 4 3 〇-■

4 + 7.1 1 1 0 9 3 9 〇

One one one

5 + 1 0. 0-1 2 5 3 5 〇

One--one

Akira 6 + 9.8 1 1 3 1 3 7 〇

7 + 9.5-1 1 8 3 8 〇

8 + 5. 9-9 3 2 9 〇

9 + 8.2-1 1 6 2 1 〇

10 + 6.8-10 03 A

11 + 1 0.1-1 2 9 A

Gold 12 + 5.6 1 9 8 A

13 + 5.9-10 A

14 + 5.8-8 7 0.5 0.5 13.0

15 + 6.1 1 9 5 0 .4 0 7.6

Table 2 (Part 2)

Table 2 (Part 3)

Change in elongation Change in shochu power Elongation ¾7j injection 5¾HC1.40 * C 40¾H ₂ S04.50 ^e C Repeated heating (%) (N / nm :) Bendability Hi? Point rot ^ K (g / m: hr) Corrosion rate (g / m ² .hr) Test

31 + 6.1 1 93

32 + 6.8 1 89 ◎

Departure

33 + 7.0-95 〇〇

34 + 6.5-99 o

35 + 7.1-98 〇〇 Description

36 + 6.0 1 90 〇〇

37 + 7.5 1 108 _ _ 1 〇 ◎

38 + 7.8 1 96 ◎ ◎

39 + 7.1-93 1 _____ o 〇

40 + 7.3 -1 10 〇 o

41 + 7.5-106 ◎ ◎ Gold

42 + 6.5-105 3.0.0 42.6 o 〇

43 + 7.4 -107 1.1 20.9 o

44 + 7.3-100 0.71 15.0 ◎ ◎

Table 2 (Part 4)

Change Elongation pressurized E injection changes strength of elongation 5¾HC1,40 * C «oxide repeating heating (%) (N / irni * ).%) Bendability point corrosion rate (g / m ^l · hr) corrosion rate (g / m: .hr) Test

1 + 3.8-55 38 m

2 + 4.8-75 36 m

Ratio 3 + 3.7-63 38 m

4 + 3.3 1 60 33 m

5 + 1.7-31 30 X comparison 6 + 2.0 1 40 30

7 + 1.0 1 17 28 X

8 + 3, 2 1 56 23 X

9 + 2. 9 — 48 15 X

10 10.4.7 1 78 B

U + 2, 6 1 45 C

Gold 12 + 1.6-28 D

13 + 3.6 1 60 12.2 364

14 + 4.1 1 63 13.5 408

15 + 4.1 1 55 XX

Table 2 (Part 5)

Change in elongation = change in proof stress elongation added salt water 喷 5¾HC1.40'C shelf ₂ S0, .50'C 鹏 repeated oxidation heating (%) (N / rnn (%) bendability score-^ .Whr) Corrosion (g / m: .hr) test

16 + 2.8-55 X X XX ratio 17 + 3.5-55 X X comparison 18 + 3.3-58 ΔX total 19 + 3.5-56 mm Δ Gold 20 + 2.0-35 mm X

21 + 4.0-70 0.9.1 18.3 〇 X

Availability of SJi

Basically, Fe-Cr alloys with excellent workability are provided, and alloys with excellent acid resistance and Z or oxidation resistance are provided. This allows the use of Fe-Cr alloys in a wide range of fields.

[B] Category B inventions

Hereinafter, the present invention will be specifically described based on examples.

(Example 1) Corresponding to Invention Alloys 1 to 6 and Comparative Alloys 1 to 6 ... Corresponding to Claim 1 Alloys having the compositions shown in Table 1 were prepared using ultra-high-purity electrolytic iron and high-purity metal materials obtained by electrolysis. was melted in a 1 0 _ ⁵ T orr more of the ultra-high vacuum melting.

This approximately 1 2 0 finished about 5 mm thick at the heating after hot rolling at 0, finally 1.0 to 2.0 ¹ After mm in cold rolling, recrystallization and the adjustment of grain size Annealing was performed at 500 to 110 ° C.

From this, tensile test specimens at room temperature and high temperature were cut out, and each test was performed in accordance with JIS (the tensile test specimen at room temperature was JIS No. 5, and the tensile test at high temperature was JIS

G O 567).

In the oxidation test, the samples in Table 1 prepared by melting high-purity metals under high vacuum were heated at 135 k for 12 hr in an electric furnace in an air atmosphere, and then air-cooled to room temperature. The weight 减 after removing the scale was measured and used as an index of oxidation resistance. Table 2 shows the results. From the results in Table 2, it is clear that both the workability and the high-temperature strength are remarkably improved in the component range of the present invention as compared with the material in the component range of the comparative example. (Example 2) Invention alloys 7 to 12, comparative alloy? Corresponding to… 9 Corresponding to claim 2 Test materials having the component ranges shown in Table 1 were produced in a 100 kg high-frequency induction heating ultra-high vacuum melting furnace. These test materials were forged, cut and hot rolled, then annealed and cold rolled to produce steel sheets with a thickness of 1.0 mm.

Then, a lmm ¹ x 50mm x 50mm specimen was prepared from these materials, ① Immersion test in 5% HC 1 at 40 ° C, 24:00

② 40% H ₂ SO ₄ , 50 ° C, 24 hours immersion test

The corrosion rate (g / m ² -hr) was measured. The results are summarized in Table 2. From the results in Table 2, it is clear that the corrosion in the acid immersion test is significantly suppressed in the component range of the present invention as compared with the material in the component range of the comparative example.

These results, 1: ¹ 6- (3: system (and 5≤ (1 "≤60) alloy, C, N, 0, P, with a total content of S and 10 Oppm less, and Ca, Ni It is clear that an alloy with excellent acid resistance can be obtained by containing one or more of Co and Co in the range of 0.01% by weight Co + Ni + 2Cu≤6% by weight.

Also, in addition to the above-mentioned components, one or more of Ti, Nb, Zr, V, Ta, W, and B are used as 0.01% ¾ %% Ti + Nb + Zr + V + Ta + W + 50B ≤ It is evident that an alloy having even more excellent acid resistance can be obtained by containing in the range of 6.0 weight.

(Example 3) Corresponding to invention alloys 13 to 26 and comparative alloys 10 to 12 ...

The alloys having compositions shown in Table 1 were melted in a high purity electrolytic iron and electrolytic C r and have use of high purity metal material 10 _ ⁷ To rr or ultrahigh vacuum melting.

This finishing at heating after hot rolling to about 1200 to about 5 mm thick, eventually with 0 to 2.0 after ¹ fine to cold rolling, annealing for adjustment of grain size and recrystallization 500 — Applied at 1100 ° C.

From this, tensile test specimens at room temperature and high temperature were cut out and subjected to respective tests in accordance with JIS (the tensile test specimen at room temperature was JIS No. 5, and the tensile test at high temperature was JIS

8 900 ° C according to GO 567).

In the oxidation test, the sample was heated in an electric furnace at 1350k for 12 hours in an air atmosphere, then cooled to room temperature, and the weight loss when the scale on the specimen surface was removed was measured. Index. Table 2 shows the test results. From Table 2, it is clear that the oxidation resistance is greatly improved in the component range of the present invention as compared with the component range of the comparative example. (Example 4) Invention alloys 27 to 29 ... Corresponding to claim 4

The alloys having compositions shown in Table 1 have use electrolytic C r and high purity metallic material as the ultra-high purity electrolytic iron 1 0 - melted in a ⁷ T 0 rr or ultrahigh vacuum melting.

This about 1 20 finish of about 5 mm thick at the heating after hot rolling at 0, final 1.0 to 2.0 cold after rolling to ¹ mm, for recrystallization and the adjustment of grain size Was performed at 500—110 ° C.

The obtained test piece, the above examples and similar ① 5% HC 1, 4 ( TC rot _{_{Shokudo, ② 4% H 2 S0 4}} , 50 Te corrosion rate, ③ 900 ° C high-temperature tensile test The results were evaluated in the same manner and the results are shown in Table 2. It is clearly shown that those falling within the scope of the present invention exhibit excellent characteristics.

(Change in elongation and proof stress)

With respect to the test materials obtained in all the above examples, changes in elongation and changes in power (yield strength) were examined. The change in elongation (%) and change in power (yield strength) (NZ mm ² ) indicate the difference in tensile properties of each alloy component from that of C + N + 0 + S + P-500 ppm. .

The basic tensile properties are as follows. F e— 18 Cr, C + N + 0 + S + P = elongation at 50 Gp pm 30%, yield strength 330 N / mm ²

F e-30 Cr, G + N + 0 + S + P = 25% elongation at 50 Oppm, 45 O N / mm

8

Two

Table 1 (Part 1)

Unit MM.% * Mark P.Pm

*

Table 1 (Part 4)

+ Z r + V + Ta + W + 50 BS i + n

Table 1 (Part 5)

+ Ta + W + 5 OB,

Table 1 (Part 6)

Unit.

* Mark ppm

a = C + N + 0 + P + S, ^ = T i + Nb + Z r + V + T a + W + 50 B, r = Ni + Co + 2Cu. 5 = 3A1 + 2S i + Mn

e = 4Ca + 4Mg + REM

Table 1 (Part 7)

Unit%

N mark ppm

a = C + N + 0 + P + S, ^ = Ti + Nb + Zr + V + Ta + W + 5 OB 7 = Ni + Co + 2Cu, 5 = 3A1 + 2S i + Mn

s = 4Ca + 4Mg + REM

Table 2 (Part 1)

Yield strength of elongation Elongation Yield strength High-temperature shochu power Oxidized fiber 5¾HC1.40'C Shelf ₂ Change in S0 change £ 1 reduction Corrosion rate 50'C Corrosion rate% N / country ^z % N / country ² N / mm ² g / ^{^{cm 2 · 12 rg / ra 2}} · hr g / m 2 · hr

1 +8.1 1 115 37.2 218 20.4 9.8X10- *

9 +6.0 -93 35.7 235 22.7 7.6X10-

s +5.8 1 95 34.3 247 295 9.1 XIO ^-4

A +6.4 -94 42.7 182 24.8 7.8X10 " ³

5 +6.9 one 102 24.4 363 22.8 2.3X10-

6 +6.4 1 96 36.1 224 20.3 1.3X10-3

Ming 7 +6.1 1 95 21.3 0.81 13.9

& +6.7 one 100 18.1 0.70 9.2 total 9 +5.8 one 95 21.5 0.61 8.5

10 +6.0 1 103 22.3 2.6 44.4 Gold 11 +6.6 1 91 24.6 0.30 6.6

12 +6.0 1 98 20.4 2.0 20.3

13 +6.1 1 93 25.1 Ku 5 X10 " ³

14 +6.8 -100 26.3 <5 X10 " ³

15 +71 -89 26.3 <5 X10 " ³ Table 2 (Part 2)

Yield strength of elongation Elongation Yield strength High-temperature shochu strength Oxidation test 5¾HC 1.0 * C 40¾H ₂ S0.Change in change Weight loss Corrosion rate 50'C corrosion rate% N / inm ² % N / mra ² N / mm ² g / cra * · ■ 12hr g '/ m ² ■ hr g / πι · hr

16 +7.3 -109 ~ ^— 30.5 <5 XIO— ³

One

17 +6.6 one 102 one 20.3 <5 X10 " ^three one

18 +8.1 1 110 1 1 20.3 <5 X10 " ³ 1

19 +5.9 -96 — 22.0 <5 X10 " ³

Departure 20 +6.0 -100 1 1 30.0 <5 XIO "" ³ --1

21 +7.3 1 105 1 26.8 <5 X10 " ³ 1 Explanation 22 +9.6 -126 24.3 9.0X10-5

23 +6.3 -100 22.3 7.3X10 " ⁵

Total 24 +6.9 -106 25.6 4.9X10 " ⁵

25 +6.0 -96 24.0 5.6X10-5

Fri 26 +7.5 -108 27.5 6.0X10 " ⁵

27 +6.3 One 110 25.0 4.1 XIO " ⁵ 0.80 14.1

28 +5.9 -87 25.7 4.0X10 " ⁵ 0.65 9.0

29 +6.6 -96 22.3 4.2X10— ⁵ 0.85 15.0

Table 2 (Part 3)

Change in yield strength elongation yield strength hot IS forces oxide纖5¾HC1.40'C Make ₂ S0 changes in elongation heavy置减corrosion rate 50'C corrosion rate% s Awakening ^{^{2% N / mra 2 N /}} mm 2 g / cm z · 12hr g / m ² · hr g / ra ² · hr

1 +3.2 one 55 31.3 280 17.5 1.2X10 " ³ ― one

2 +1.6 1 28 33.269 17.6 1.4X10- ³ ― ―

3 +1.4 -27 30.2 288 17.1 6.8X10-

4 +1.8 -33 34.5 241 16.9 9.8X10- ³ ― ―

5 +2.1 one 35 36.1 224 17.3 1.9X10- ²

Comparison

6 +2.1 one 39 37.9 207 17.5 2. & X1CT ²

• 7 Hot rolling not possible

Combination

8 +2.9 1 56 17.6 5.2 102

9 +7.3 1 103 17.0 8.8 160 Fri

10 +1.6 -28 16.8 9.8X10- ³

11 +1.5 one 25 17.0 2.5X10 " ²

12 +1.8 -24 17,3 8.7X10- ²

Industrial applicability

Since the alloy of the present invention is excellent in workability, strength at high temperature, or acid resistance and Z or oxidation resistance in addition to these, it is suitably used for applications such as pipes for automobile exhaust gas.

[C] Category C invention

(Example 1) Corresponding to invention alloys 1 to 10 and comparative alloys 1 to 7 ... corresponding to claims 1 and 2 A 10 kg alloy having the chemical composition shown in Table 1 was melted in a vacuum melting furnace, produced, and hot rolled. To a hot-rolled sheet with a thickness of 4 mm, heat-rolled for recrystallization, subjected to descaling, and then cold-rolled into a cold-rolled sheet with a thickness of 0.7 mm after cold rolling. It was fired and made into a cold plate.

The following tests were performed on the alloy sheets thus obtained.

(Workability)

Using invention alloys I and 6, and comparative alloys 1 and 6, the elongation value was measured by a tensile test in accordance with JIS Z-2241, and after 50% cold rolling, an adhesion bending test was performed at 180 in the C direction. The state of cracking at the time was observed. The evaluation was performed as follows.

なし No crack

△ Small crack

Large crack

The results are shown in Table 2.

When the total amount of C, N, 0, P, and S is 10 Oppm or less, no cracking occurs due to close contact bending in the C direction after 50% cold rolling, whereas if it exceeds 10 Oppm, cracking occurs. It can be seen that the workability decreases. Also, when the elongation is compared with the same amount of Cr and the same amount of Mo, it can be seen that when the total amount of C, N, 0, P and S exceeds 10 Oppm, it decreases by about 7 to 8%. -Eating and acid resistance) The surfaces of the test specimens of Comparative Alloy 2 and Invention Alloys 1 and 7 were polished with Emery # 500, and the pitting corrosion resistance was immersed in a 30 ° (:, (2% FeCl ₃ + 1Z20HC 1) aqueous solution for 4 hours. The acid resistance was evaluated by the corrosion rate calculated from the corrosion weight loss, and the acid resistance was evaluated by the corrosion rate calculated from the corrosion weight loss after immersion for 4 hours in 0.1% by weight HC1 aqueous solution. .

Samples were prepared in the same manner as above for Comparative Alloy 5, Inventive Alloy 10 and Inventive Alloy 6 and had a pitting resistance of 30 ° C, immersed in (5% FeCl ₃ + 1 / 20N HC 1) aqueous solution for 4 hours. The acid resistance was evaluated by the corrosion rate calculated from the corrosion weight loss after crushing, and the acid resistance was evaluated by the corrosion rate calculated from the corrosion weight loss after immersion in a 0.3% by weight HC1 aqueous solution for 4 hours. Table 2 shows the results.

Comparative Alloy 4, Inventive Alloy 4, Inventive Alloy 5 A sample was prepared in the same manner as above, and was immersed for 4 hours in an aqueous solution of (5% FeCl ₃ + 1 / 20N HC 1) with a pitting resistance of 30 ° C. The acid resistance was evaluated based on the corrosion rate calculated from the corrosion weight loss, and the acid resistance was evaluated based on the corrosion rate calculated from the corrosion weight loss after immersion in a 0.3% by weight HC1 aqueous solution for 4 hours. Table 2 shows the results.

Comparative Alloy 3, Inventive Alloy 2, Inventive Alloy 8 Samples were prepared in the same manner as above, and had a pitting resistance of 80 ° C and 4 hours in an aqueous solution of (5% FeC13 + 1/2 ON HC1). The corrosion resistance was evaluated by the corrosion rate calculated from the corrosion weight loss after immersion, and the acid resistance was evaluated by the corrosion rate calculated from the corrosion weight loss after immersion in a 5% by weight HC1 aqueous solution for 4 hours. Table 2 shows the results.

Comparative alloy 7, Inventive alloy 3, Inventive alloy 9 A sample was prepared in the same manner as above, and had a pitting resistance of 80 ° C, in an aqueous solution of (10% FeC13 + 1/2 ON HC1). The acid resistance was evaluated by the corrosion rate calculated from the corrosion weight loss after immersion for 4 hours, and the acid resistance was evaluated by the corrosion rate calculated from the corrosion weight loss after immersion for 4 hours in a 5% by weight HC1 aqueous solution. Table 2 shows the results.

It can be seen that the pitting corrosion resistance is remarkably improved by containing M 0 in the range of the present invention, and the acid resistance is further improved by containing Ni, Co, and Cu in the range of the present invention.

(Example 2) Inventive alloys 1 to 25, corresponding to comparative alloys 8 to 11-, corresponding to claim 3 An alloy having the composition shown in Table 1 was prepared by using ultra-high-purity electrolytic iron, electrolytic Cr and high-purity metal material. and have use was melted in a 1 0 _ ⁷ T 0 rr or more of ultra-high vacuum.

After heated to about 1 2 0 0 hands, about 5 mm finishing thickness in hot rolling, eventually from 1.0 to 2 0 ¹ after cold rolling negation, recrystallization and the adjustment of grain size Annealing was performed at 500 to 110 ° C.

From this, tensile test specimens at room temperature and high temperature were cut out and subjected to various tests in accordance with JIS (the room temperature tensile test specimen was designated as JIS No. 5, and the high temperature tension was determined as JIS

G O 567).

In the oxidation test, the specimen was heated at 135k for 12 hours in an electric furnace in the atmosphere, then cooled to room temperature, and the weight loss when the scale on the specimen surface was removed was measured. And

It can be seen that the oxidation resistance is significantly improved by containing Al, Si, Mn or Ca, Mg, REM or both in the range of the present invention.

(Example 3) Inventive alloy 26, 27 ... Corresponding to claim 4

The alloys with the compositions shown in Table 1 are made of ultra-high purity electrolytic iron, electrolytic Cr and high-purity metal materials. Stomach was melted in a 1 0- ⁷ To rr or more of ultra-high vacuum.

After heating this to about 1200, it is finished to about 5 mm thickness by hot rolling, and finally cold-rolled to 1.0-2.0 匪, then recrystallized and adjusted for grain size. Annealing was performed at 500 to 110 ° C.

In the same manner as in the above examples, acid resistance and oxidation resistance were evaluated. It is clear that the alloy according to the invention exhibits excellent properties.

Table 2 shows the test results.

(Change in elongation and proof stress)

The change in elongation () and the change in heat resistance (yield strength) (N / country ² ) of the test materials obtained in all of the above examples were calculated for each alloy component as C + N + 0 + S + It shows the difference in bow I tension characteristics from that of P = 500 ppm.

The basic tensile properties are as follows.

F e -18Cr, C + N + O + S + P = 500 ppm, elongation 30%, resistance 330 N / mm ² Fe-30Cr, C + N + O + S + P = 500 ppm, elongation 25%, resistance 450N / picture ²

/ £ 60SS006dd / § £ 6 OAV l

(2 o) I

Table 1 (Part 3)

Unit H * mark ppm

a; = C + N + O + S + P, / 9 = Ni + Co + 2Cu ₍ r = 3 A 1 + 2S i + Mn, 5 = 4 Ca + 4Mg + REM

Table 1 (Part 4)

Unit: ppm mark ppm

a = C + "N + 0 + S + P,> S = Ni + Co + 2Cu, r = 3 A 1 + 2S i + n, d = Ca + 4 + REM

Table 2 (Part 1)

Shochu pitting corrosion, heavy weight g / m 'hr) Occupational work' acidification test growth of shochu strength increase adhesion weight change change bending bending 2% FeC + 5% FeCh + 5% FeC + 10% FeCl ₃ + 0 .lwt% 0.3wt¾ 5wt¾

1/20 NHCl 1/20 NHCl 1/20 NHC l 1/20 NHCl HC 1 HC 1 HC 1 g / cm *

% N / iran *% 3 O'C 3 O'C 8 O'C 8 O'C

1 + 5.8 1 95 4 1 〇 59 1 660

2 + 6.2 one 90

Departure 0.1 1 or less 3.1

3 + 8.5 -Π1 0.0 1 or less 1.0

4 + 8.9 1 130 5.0 59

Light

P 10 10 9-148 5.2 40

6 + 5.8 1 89 37 〇 4. 9 47

Combination

7 + 9.1 -121 56 290

8 + 6.5 -105 0.0 1 or less 1.2

Money

9 + 9.3 -12 0.0.0 1 or less 0.06

10 + 7.3 -111 4. 9 60

Flutter Table 2 (Part 2)

Shochu Pitting Corrosion · Weight Loss (g / m ² · hr) Positive Weight Loss (g / m ² · hr) Oxidation Elongation of shochu power of coexistence Adhesion Weight loss change Bending 2% FeCl ₃ + 5 % FeCl ₃ + 5% FeClo + 10% FeCl 0.lwt¾ 0.3wt¾ 5wt¾

1/20 NHCl 1/20 NHCl 1/20 NHCl 1/20 NHCl HC 1 HC 1 HC 1 g / cm ^¾

% N / mm ² % 3 O'C 3 O'C 8 O'C 8 O'C

11 + 8.1 1 119 4.9 1 1 ~-1.3 X

12 + 6.0 1 88 1 4.8 1 ― 1.1 X

13 + 7.0 1 100 3.8 <1.0 X

14 + 7.2 -100 ≤0.0.1 <1.0 Description

15 10 8.0 1 89 ≤ 0.0 1 <1 1.0 x

16 + 7.8 -103 ≤0.0 1 <1.0 m

17 + 6.5 1 90 4.8 1.8 X

18 + 8.0 1 100 4.9 <1.0 X Gold

19 + 6.9 1 95 5.2 <1.0 X

20 + 8.0 -100 ≤ 0.0.1 <1.0

Table 2 (Part 3)

Shochu Pitting Corrosion · Weight Reduction (g / m ² · hr) Difficulty 'Weight Reduction (g / m ² · hr) Oxidation Test Elongation of Elongation Force Adhesion 蜇 Female Change Bending 2% FeCl ₃ + 5% FeCh + 5% FeCl ₃ + 10% FeCl j -f 0.lwt¾ 0.3wt¾ 5wt¾

1/20 NHCl 1/20 NHCl 1/20 N-HCl 1/20 NHCl HC 1 HC 1 HC 1 g / cm * 12

% N / mm ² % 3 O'C 3 O 'C 8 O'C 8 O'C

21 + 7.6-87 ≤ 0.01 <1.0 10 rounds 22 + 7.5-90 ≤ 0.01 x 1.0 X10

23 + 6,8-89 4.6 <1.0 XIO light

24 + 6.1 1 88 4.9 <1.0 XIO combined 25 + 8.0 1 99 ≤0.01 <1.0 XIO

26 10 5,9 1 90 5.40 40 <1.0 xio

27 + 7.5 one 88 ≤0.01 1.1 <1.0 XIO

Table 2 (Part 4)

Pitting corrosion resistance · weight reduction (g / m ² · hr) MltTo. | E weight reduction (g / m * · hr) 伸び chemical test elongation of shochu force elongation cohesion ffi amount change change bending ο) re i 3 Byeon 0 lwt% νOn LA

1/20 ΝHC1 1/20 ΝHCl 1/20 ΝHC1 1/20 HClHCl HC 1 HC 1 HC 1 g / cm ²

% N / country ² % U ο υ υ Ο Ο W

1 + 2.3 1 46 34 Λ

2 + 7.5 1 89 1 9 fi 68 0

Ratio 3 + 5.9 1 90 0 9 3.5

4 + 11.0 -128 8

Comparison 5 + 5.6 1 95 1 0.7 8 86

6 + 1.3 1 26 29 X 1 7 + 3.0 1 36 1.8 4.9

8 + 2.8 1 46 8.3 1.3 XI Gold 9 + 2.9 1 39 1.5 8.9 XI

10 + 5.8 1 83 9.8 1.6 X1

11 + 7.0 1 90 1.2 7.5 XI

Industrial applicability

The alloy of the present invention is excellent in workability and pitting corrosion resistance and, in addition, is excellent in acid resistance, Z or oxidation resistance, and is therefore suitably used for applications such as pipes for automobile exhaust gas.

[D] Category D invention

C Example 1)

A 10 kg alloy having the chemical composition shown in Table 1 was melted and manufactured in a vacuum melting furnace, hot-rolled into a hot-rolled sheet having a thickness of 4 mm, and subjected to hot-rolled sheet annealing for recrystallization. After the scale, a cold-rolled sheet with a thickness of 0.7 mm was finally cold-rolled by recrystallization annealing to obtain a cold-rolled annealed sheet.

The following tests were performed on the alloy sheets thus obtained.

(Workability)

Measurement of elongation value by tensile test in accordance with J IS Z-2241 using Inventive Alloys 1 and 2 and Comparative Alloy 2, and after 50% cold rolling, 180 ° C adhesion bending test in C direction The state of the cracks at the time of breaking was observed. The evaluation was performed as follows.

なし No crack at all

△ Small crack

X crack large

The results are shown in Table 2.

When the total amount of C, N, 0, P and S is 10 Oppm or less, no cracks are generated by the close contact bending in the C direction after 50% cold rolling, whereas when it exceeds 10 Oppm, cracks are generated. It can be seen that the workability is reduced. In addition, when the elongation is compared with the same amount of Cr and the same amount of Mo, it is found that when the total amount of C, N, 0, P and S exceeds 10 Oppm, the elongation is reduced by about 5 to 6%. (Pit and corrosion resistance)

The specimen surface using Emeri # 5 0 0 polished samples, pitting corrosion resistance is Ataishi commentary in corrosion rate calculated from the corrosion weight loss after immersing for 4 hours at Fe Cl ₃ + HC 1 aqueous solution shown in Table 2, The intergranular corrosion resistance is determined by subjecting the above sample to TIG welding (bead-on) and bending the welded portion after copper sulfate monosulfate test in accordance with JISG-0572 (r = 2 t, 180 ° The evaluation was based on the presence or absence of cracking due to bending.

なし No crack

△ Small crack

X big crack

Table 2 shows the results.

(Intergranular corrosion resistance, acid resistance)

A sample was prepared in the same manner as above, and the intergranular corrosion resistance was evaluated in the same manner as described above. Shochu acidity was evaluated based on the corrosion rate calculated from the corrosion loss after immersion for 24 hours in the HC1 aqueous solution shown in Table 2. Table 2 shows the results.

(Oxidation test)

酸化 The oxidation test was performed by heat treatment at 135k for 12 hours in the air, and the weight loss after scale removal was evaluated.

Table 2 shows the results.

(Change in elongation and proof stress)

Changes in elongation and changes in power (yield strength) of the obtained test materials were examined. The change in elongation (%) and the change in heat resistance (yield strength) (N / mm ² ) are the values of C + N + 0 + S + P = 500 ppm for each alloy component. Shows the difference in tensile properties. The basic tensile properties are as follows.

Fe—18Cr, C + N + 0 + S + P = 500 ppm, elongation 30%, power resistance 33 ON / ²

Fe- 30Cr, C + N + O + S + 25% elongation at P = 500 ppm,耐Ka 45 ON / image ²

By adding M 0 in the range of the present invention, the pitting corrosion resistance is remarkably improved, and by adding an appropriate amount of Ti, Nb, V, Ta, W, Zr, B, the intergranular corrosion resistance at the weld is improved. You can see that. Furthermore, it is clear that acid resistance can be significantly improved by adding appropriate amounts of Ni, Co and Cu. It is also clear that the addition of one or more of Si, Mn, A1 and one or more of Z or Ca, Mg, REM improves the oxidation resistance.

Table 1 (Part 1)

〇

Unit * mark ppm

a = C + N + 0 + P + S, β = Ti + Nb + Zr + V + Ta + W + 50B r = N Co + 2Cu, δ = 3Al + 2Si + Mn, ε = 4Ca + 4Mg † REM

Table 1 (Part 3)

Table 1 (Part 4)

Unit Lightning amount ^ ppm mark ppm

a = C + N + 0 + P + S, β = Ti + Nb + Zr † V + Ta + W + 50B, r = Ni + Co + 2Cu, 5 = 3Al + 2Si + Mn, ε = 4Ca + 4Mg + REM

Table 1 (Part 5)

Unit Mfi%, * mark ppm

a = C + N + 0 + P + S, β = Ti + b + Zr † V + Ta + W + 50B _r r = Ni + Co + 2Cu, 5 = 3Al + 2Si + Mn, ε = 4Ca † lg + RB

Table 1 (Part 6)

Table 2 (Part 1) Pitting corrosion resistance.mw · hr)

Elongation of elongation

Change Bend 2¾FeCl ₃ + 5¾FeCl ₃ + 5¾FeCh † 10¾FeCl ₃ +

1 / 20N HCl 1/20-HCl 1 / 20N HCl 1 / 20N HCl

² % 30 ° C 30 ° C 80 ° C 80 ° C

1 + 8.0 1 103 .4 ¹ 〇 60 1 ―

Departure 2 + 6.5 1 90 37 〇 1 1 ― ―

3 +10.0 ― 121 1 1 ― 4 0 ― ― Bright 4 + 5.9 1 90 ― ― ≤ 0.01

5 + 7.0 1 100 ≤ 0.01 6 +10,3 1 ¹¹¹ ≤ 0,01

7 + 6.5-90 ≤ 0.01 Gold 8 + 8.1-119 3.99

9 + 7.0 1 108 3.7

Table 2 (Part 2)

而赚'Φ Jing down ^{(g / πι 2 · hr)} mm m.

Xiaolano copper broiler

U. oWt ^ DWl¾ 7as Γ

HC1 HC1 g / m ² · 12hr

1 1 ― 1 2 3 ― ― 〇

3 ― ― 8.0 X10 ~ ⁴ Description ⁴ 3.1 2.6 X10 " ⁴

5 1.0 0 6 1 2

7 0 0.1 〇 Gold 8 ≤1.0 X10 " ⁴ 〇

9 ≤1.0 X10 ^1-4 〇

Table 2 (Part 4)

Jioki's army reduction (g / m ² -hr)

mm Copper barley

V · OfY and 0 fft test

HC1 HCl g / m ² · 12hr

10 11 ≤1.0 XIO " ⁴ 〇 Development 11 11 ≤1.0 xlO-1 ⁴発

12 ― 1 ≤L 0 XIO- ⁴ Description 13 ≤10 xlO " ⁴ 〇 co 14 ≤10 XIO" ⁴ Union 15 ≤10 XIO " ⁴ 〇

16 ≤1.0 XIO ' ⁴ 〇 Gold 17 ≤io xio- ⁴ 〇

18 ≤1.0 XIO 〇

Table 2 (Part 5)

t

o

Table 2 (Part 6)

(4 Sft reduction (gm ² * hr)

0. l t¾ 0.3wt¾ 5 t¾ Bending test HCi HCI HCI g / m ²

1 ― ratio 2 X comparison 3 bond 4 Δ gold 5〇

6 〇

Availability of i

When the total amount of C, N, 0, P, and S of the present invention is 100 ppm or less, a specific amount of at least one of Mo and Ti, Nb, Zr, V, Ta, W, and B is contained. The Fe-Cr alloy has excellent workability and remarkably excellent pitting corrosion resistance and corrosion resistance at the weld (shoulder intergranular corrosion).

Further, Fe—Cr alloys containing at least one of Ni and CCo are remarkably excellent in acid resistance.

Further, the addition of at least one of Si, Mn, and AI and / or at least one of Ca, Mg, and REM further improves the oxidation resistance. These are useful for various purposes.

Claims

The scope of the claims

1. Fe * with excellent workability characterized by Cr * ¾3 to 60fi¾%, the total amount of C, N, 0, P and S is 100 ppm or less and the balance of Fe and unavoidable impurities. Cr alloy.

2. The Cr content is 5-60% by weight, the total amount of C, N, 0, P and S is 100 ppm or less, and at least one selected from Ni, Co and Cu is represented by the following formula.

Fe-Cr alloy with excellent workability and acid resistance, characterized in that it contains (1) an amount that satisfies, and is composed of the balance of Fe and unavoidable impurities.

0.01% by weight ≤Ni + Co + 2Cu≤6% by weight …… (1)

3. The Cr content is 3 to 60% by weight, the total amount of C, N, 0, P and S is 100 ppm or less, and at least one selected from Si, Mn and A1 is represented by the following formula.

(2) It must contain at least one selected from Z or C a, Mg and rare earth element (REM) in an amount that satisfies the following formula (3), with the balance being Fe and inevitable impurities Fe-Cr combined with excellent workability and oxidation resistance characterized by

0.1 weight ^ 3 A 1 + 2S i + Mn ≤ 50% by weight …… (2)

0.00 m% ≤ 4 Ca + 4 Mg + REM ≤ 0.2 wt%… "-(3)

4. The Cr content is 5-60 weight%, the total amount of C, N, 0, P and S is 100 ppm or less, and at least one selected from Ni, Co and Cu is represented by the following formula

A content that satisfies (1) and contains at least one selected from Si, Mn and A1 in an amount that satisfies the following formula (2) and / or C a, Mg and rare earth elements (REM) Fe—Cr alloys that are excellent in workability, acid resistance and oxidation resistance, characterized in that they contain at least one selected from the following formula (3) and that the balance consists of Fe and unavoidable impurities.

0.0 1% by weight ≤Ni + Co + 2Cu≤6% by weight "" "(1)

0.1% by weight ≤3A1 + 2S i + Mn≤5 O% by weight… "-(2) '0.001 1% by weight ≤4Ca + 4Mg + REM≤0.2 2%

5. Cr content is 3 ~ & 0% by weight, total amount of C, N, 0, P and S is less than 100 ppm, and selected from Ti, Nb, Zr, V, Ta, W and B Fe-Cr alloy containing at least one kind in an amount that satisfies the following formula (1) and characterized by the balance of Fe and unavoidable impurities and excellent in workability and high-temperature strength.

0.0 1 &% ≤ T i + N + Z r + V + T a + W + 50 B ≤ 6 M &%

6. Cr content of 5 to & 0 weight, total amount of C,, 0, P and S is 100 ppm or less, at least one selected from Ti, Nb, Zr, V, Ta, W and B The following formula

(1) and at least one selected from Ni, Co and Cu in an amount satisfying the following formula (2), with the balance being Fe and unavoidable impurities. Fe-Cr alloy with excellent heat resistance, high temperature strength and acid resistance.

0.0 1 weight ^ T i + Nb + Zr + V + Ta + W + 50 B≤6% by weight

...... (i)

0.0 1 ES ≤N i + C o + 2 C u≤8 Μ%…-(2)

7. Cr content of 3 to 60% by weight, total amount of C,, 0, P and S of 100 ppm or less, at least one selected from Ti, Nb, Zr, V, Ta, W and B In an amount satisfying the following formula (1), and at least one selected from A1, Si and Mn in an amount satisfying the following formula (3) and / or from Ca, Mg and rare earth element (REM). Fe—Cr alloy excellent in workability, high-temperature strength and oxidation resistance, characterized in that it contains at least one selected material in an amount satisfying the following formula (4), and is composed of the balance of Fe and unavoidable impurities.

0.01 Μ% ≤Ύ i + Nb + Z r + V + Ta + W + 50 B≤ 6 M &%

…… (1)

0.1% by weight ≤3A1 + 2S i + Mn ≤50% by weight (3)

0.001 weight 4 Ca + 4Mg + REM ≤ 0.2% by weight …… (4) 8, Cr content is 5 to 60% by weight, the total amount of C, N, 0, P and S is 100 ppm or less, At least one selected from Ti, Nb, Zr, V, Ta, W and B is contained in an amount satisfying the following formula (1), and at least one selected from Ni, Co and Cu is contained in the following formula (2) ), And at least one selected from Al, Si and Mn is selected from those satisfying the following formula (3) and / or from Ca, Mg and rare earth elements (REM) Fe—Cr alloy with excellent workability, high-temperature strength, acid resistance and oxidation resistance, characterized in that it contains at least one kind in an amount satisfying the following formula (4) and the balance consists of Fe and unavoidable impurities.

0.0 \ &% ≤T i + Nb + Z r + V + Ta + W + 50 B≤ 6 M.%

…… (1)

0.01% by weight ≤Ni + Co + 2Cu≤6% by weight …… (2)

0.1 weight 3 A 1 +2 S i + Mn ≤ 50% by weight (3)

0.004 Ca + 4Mg + REM ≤ 0.2% by weight …… (4)

9. Cr content is 5 to 60% by weight, the total amount of C, N, 0, P and S is 100 ppm or less, Mo content is 0.5 to 20% by weight, and the balance of Fe and ^ Fe-Cr combined with excellent workability and pitting resistance characterized by being made of pure material

10. Cr content is 5 ~ 60% by weight, total content of C, N, 0, P and S is 5> 100ppm or less, Mo content is 0.5 ~ 20% by weight, further select from Ni, Cu, Co Contains at least one of the following formulas in an amount that satisfies the following formula (1), with the balance Fe and inevitable

Fe with excellent workability, pitting resistance and acid resistance characterized by being composed of S3 impurities

―Shi Γ ΊΖΙ'ΞΕΟ

0.01 weight ^ N i + Co + 2Cu weight% …… (1)

11. Cr content is 5-60% by weight, and the total amount of C, N, 0, P and S is

100 ppm or less, Mo content is 0.5 to 20% by weight, and one or more selected from A1, Si and Mil satisfy the following formula (2) and Z or Ca,

Workability, pitting corrosion resistance and oxidation resistance, characterized by containing at least one selected from Mg and rare earth elements (REM) in an amount satisfying the following formula (3), with the balance being Fe and unavoidable impurities. Excellent Fe-Cr alloy.

0.1% by weight ≤3Al + 2Si + Mn≤50% by weight …… (2)

0.00 l £ *% ≤4 Ca + 4Mg + REM≤ 0.2% by weight… "-(3)

12. Cr content is 5-60% by weight, and the total amount of C, N, 0, P and S is

10 Oppm or less, Mo content is 0.5 to 20% by weight, and further contains at least one selected from Ni, Cu and Co in an amount satisfying the following formula (1), and A 1, S. i and

At least one of Mn can be selected from the following formula (2) and Z or It contains at least one selected from Ca, Mg and rare earth elements (REM) in an amount that satisfies the following formula (3), and is composed of a balance of Fe and unavoidable impurities. Fe-Cr alloy with excellent heat resistance and oxidation resistance.

0.0 1% by weight ≤ Ni + Co + 2Cu ≤ 6% by weight (1)

0.1 weight 3 A 1 +2 S i + Mn ≤ 50% by weight …… (2)

0.00 lfi *% ≤4 Ca + 4Mg + REM≤0.2 wt% …… (3)

1 3.Cr content is 5 ~ 60 weight, total amount of C, N, 0, P and S is less than 100 ppm, 1 ^ 0 content is 0.5 ~ 20 weight, And at least one selected from Ti, Nb, Zr, V, Ta, W and B is represented by the following formula

Fe—Cr alloy with excellent workability, pitting corrosion resistance and welded part corrosion resistance, characterized in that it contains (1) an amount that satisfies and contains the balance of Fe and inevitable impurities.

0.0 1% by weight ≤ Ti + Nb + Zr + V + Ta + W + 50 B ≤ 1.0% by weight

(1)

14. The Cr content is 5 to 60% by weight, the total amount of C, N, 0, P and S is less than 100 ppm, the Mo content is 0.5 to 20% by weight, and T i, Nb, Zr, V, Ta, W and B

(1) is satisfied, and one or more selected from Ni, Cu and Co

Fe—Cr alloy with excellent workability, pitting corrosion resistance, corrosion resistance at welds, and acid resistance, characterized by containing an amount that satisfies (2) and consisting of the balance of Fe and inevitable impurities.

0.0 1S% ≤ Ti + Nb + Zr + V + Ta + W + 50B ≤ 1.0 wt%

(1)

0.0 1% by weight ≤ Ni + Co + 2Cu ≤ 6% by weight (2)

15. The Cr content is 5 to 60% by weight, the total amount of C, N, 0, P and S is not more than Ι Ο ρ ρ pm, the Mo content is 0.5 to 20% by weight, and T i, Nb, Zr, V, Ta, W and B

Contains at least the amount satisfying (1), and at least one selected from Si, Mn and A1 is selected from the amount satisfying the following formula (3) and Z or C a, and the rare earth element (REM) Fe-Cr with excellent workability, pitting corrosion resistance, corrosion resistance at welds and oxidation resistance, characterized by containing at least one kind in an amount that satisfies the following formula (4), with the balance being Fe and unavoidable impurities. alloy.

0.0 lM½≤Ti + Nb + Zr + V + Ta + W + 50B≤1.0 wt%

…-… (1)

0.1 wt% ≤ 3A1 + 2S i + Mn ≤ 50 wt% —— · (3) 0.000 lSfi% ≤ 4Ca + 4Mg + REM ≤ 0.2 wt% (4)

16. The Cr content is 5 to 60% by weight, the total amount of C, N, 0, P and S is 10 Oppm or less, the 1 ^ 0 content is 0.5 to 20% by weight, and Ti, Nb , Zr, V, Ta, W and B

(1) It contains at least one type selected from Ni, Cu and Co in an amount satisfying the following formula (2), and one type selected from Si, Mn and A1 The above is contained in an amount satisfying the following formula (3) and / or at least one selected from Ca, Mg and rare earth element (REM) in an amount satisfying the following formula (4), with the balance being Fe and inevitable Fe-Cr alloy with excellent workability, pitting corrosion resistance, corrosion resistance of welds, acid resistance and oxidation resistance characterized by impurities.

0.01% wt≤Ti + Nb + Zr + V + Ta + W + 50B≤1.0% wt

(1)

0.01% by weight ≤Ni + Co + 2Cu≤6% by weight (2)

0.1 weight 3 A 1 + 2S i + Mn ≤ 50% by weight (3)

0.00 lMM% ≤4Ca + 4Mg + REM≤0.2 wt% (4)