KR960005601B1 - Iron-chromium alloy with high corrosion resistance - Google Patents

Abstract

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Description

P-added Fe-Cr alloy with excellent corrosion resistance

1 is a diagram showing the relationship between corrosion resistance and the total amount of C, N, O, and S;

2 is a diagram showing the relationship between weather resistance and P content.

3 is a diagram showing the relationship between the corrosion resistance of a hole and the total amount of C, N, O, and S;

4 is a diagram showing the relationship between the hole corrosion resistance and the Mo content.

5 is a diagram showing a relationship between oxidation resistance and Ni + Co + 2 Cu value.

6 is a diagram showing a relationship between oxidation resistance and a value of 3Al + 2Si + Mn.

The present invention relates to a Fe-Cr alloy excellent in corrosion resistance.

In particular, it relates to Fe-Cr-based stainless steel.

Although Fe-Cr alloys are generally known as materials having excellent corrosion resistance, it is known that C, N, O, and S in Fe-Cr alloys adversely affect the corrosion resistance for the following reasons.

C, N: The appearance of Cr deficiency layer by the formation of carbonitride at the grain boundary.

O, S: Weight of the rust generating point by weight of inclusions.

In other words, it is well known that the reduction of these impurity elements is effective in improving the corrosion resistance of the Fe-Cr alloy, and the Cr-deficient layer is reduced by the reduction of C, N, O and S and the addition of carbonitride elements such as Ti and Nb. Removal has been shown.

Next, the conventional technique regarding the improvement of the corrosion resistance of Fe-Cr alloy is shown.

Japanese Patent Application Laid-Open No. 61-186451 discloses a 25-50% by weight Fe-Cr alloy, which reduces C and N to a certain amount, and at the same time contains a certain amount of Si, Mn and Mo. Excellent alloys are proposed.

Japanese Patent Application Laid-Open No. 2-1902 discloses a Fe-Cr alloy having a Cr content of more than 20.0% by weight and not more than 25.0% by weight, particularly reducing C and N, and containing a specific amount of Mo, Mn and Nb. We propose a corrosion-resistant ferritic stainless steel that has excellent high temperature cracking resistance and good toughness at the welded part.

Japanese Patent Application Laid-Open No. 3-2355 discloses a Cr-containing Fe-Cr alloy having a Cr content of 16.0-25.0% by weight, in particular in the ratio of Nb to the total amount of C and N, cold workability, toughness and corrosion resistance. This excellent ferritic stainless steel is proposed.

However, the effect of improving the corrosion resistance in the Fe-Cr alloy proposed in the above prior art may also be insufficient.

For example, automotive exhaust gas materials that require corrosion resistance in the design of building chemical plants used in corrosive environments such as near the coast are required to be improved in corrosion resistance.

In addition, attempts to add P for improvement of corrosion resistance have been made in ordinary steel, and have been put to practical use as weather resistant steel and seawater resistant steel, and there are examples of application to Cr-containing steel, but the corrosion resistance in stainless steel is improved. The effect is not enough.

Therefore, the improvement of the corrosion resistance in Fe-Cr type alloy also has strong demand now.

Accordingly, an object of the present invention is to provide a Fe-Cr-based alloy with further improved corrosion resistance as compared to the conventional Fe-Cr-based alloy.

In particular, it is to provide a highly corrosion-resistant steel suitable for stainless steel for building materials, stainless steel for chemical plants and stainless steel for exhaust pipes of automobiles used in severe corrosive environments near the coast.

In order to achieve the above object, the present invention has conducted a thorough study and, as a result, significantly reduces the amount of C, N, O and S present as impurities in the conventional Fe-Cr alloy, and at the same time contains a specific amount of P. It was found that the Fe-Cr alloy was remarkably superior in weather resistance.

Further, by adding a specific amount of one or more selected from Ti, Nb, V, Zr, Ta, W, and B to the above-described P-added Fe-Cr alloy, the grain boundary corrosion resistance is further improved, and a specific amount of Mo is added. It was found that by adding, the hole corrosion resistance was remarkably improved.

In addition, it was found that the acid resistance was remarkably improved by adding a specific amount of one or more selected from Ni, Co, and Cu, and oxidation resistance was achieved by adding a specific amount of one or more selected from Al, Si, and Mn. It has been found to be improved, and the present invention has been completed.

That is, according to the present invention, the Cr content is 5% by weight or more, the total amount of C, N, O, and S is 100 ppm or less, the P content is 0.01-1.0% by weight, and it is characterized in that the remainder is Fe and unavoidable impurities. An Fe-Cr alloy having excellent corrosion resistance is provided.

In addition, as an aspect of the present invention, various elements can be added as long as the effects of the basic invention described above are not impaired, whereby further improved steel can be obtained.

Next, the present invention will be described in detail again with reference to the drawings.

1 shows the relationship between weather resistance and the total amount of C, N, O and S. FIG.

This figure shows the incidence of rust on the surface of Fe-20% Cr-0.05% P alloys after exposure to air for 6 months (exposure at an angle of 36 ° to the south) within a distance of 5 m in the coastal industrial zone. It shows the result evaluated by the following three steps.

1: no rust

2: Stain shape corrosion

3: Point shape red rust occurrence

If the total amount of C, N, O and S is 100 ppm or less, no rust occurs and it is clear that the weather resistance is remarkably excellent.

FIG. 2 shows the relationship between the occurrence of rust after one year of atmospheric exposure and the P content of Fe-18% Cr alloys having a total amount of C, N, O and S of 100 ppm or less and 100 ppm or more.

The incidence of rust was visually assessed in the following four steps.

1: Light stain stain

2: front stain shape corrosion

3: point shape red rust with front stain shape corrosion

4: Front red rust

From Fig. 2, it is clear that the Fe content of the total amount of C, N, O, and S is 100 ppm or less, and the weather resistance is remarkably excellent when the P content is 0.01% or more.

3 shows the relationship between the total amount of C, N, O, and S and the hole corrosion potential [V ′ _C10 (MV vs. SCE)] for Fe-18% Cr-0.02% alloy.

If the total amount of C, N, O and S is 100 ppm or less, it is clear that the hole corrosion resistance is excellent.

As shown in FIGS. 1 to 3, when the total amount of C, N, O, and S is extremely small, and the content of P is greater than or equal to a certain value, the corrosion resistance of the Fe-Cr alloy is remarkably improved. do.

4 shows the relationship between the Mo content and the hole corrosion potential [V ′ _C10 (MV vs. SEC)] for Fe-18% Cr-0.1% P alloys in which the total amount of C, N, O and S is 100 ppm or less.

When the Mo content is 0.05% by weight or more, it is clear that the hole corrosion resistance is excellent again.

5 shows the degree of corrosion and Ni + Co + 2Cu when the total amount of C, N, O and S was immersed for 18 hours in 1% Hcl boiling on Fe-20% and Cr-0.03% P alloys of 100 pm or less. The relationship with the value (weight%) is shown.

When the value is 0.01% by weight or more, it is obvious that the degree of corrosion is reduced and the acid resistance is improved.

FIG. 6 is a repeated oxidation test in which 1 cycle of cooling for 12 minutes is performed at 1075 ° C. for 30 minutes in an atmosphere with respect to Fe-20% Cr-0.06% P containing a total amount of C, N, O and S of 100 ppm or less. The weight change was measured every 25 cycles, and the relationship between the number of cycles until the abnormal oxidation occurred (number of cycles when the oxidized weight exceeded 5.0 mg / m ² ) and the value (% by weight) of 3Al + 2Si + Mn was measured. It is shown.

When the value of 3Al + 2Si + Mn is 0.1% by weight or more, it is clear that the oxidation resistance is remarkably excellent.

Next, the structure of this invention is demonstrated concretely for every aspect.

More preferred embodiments of the present invention and the advantages based thereon will become apparent.

(1st aspect)

Cr: 5 weight% or more, Preferably it is 10 weight% or more.

Cr content in the above range is an essential condition for the alloy of the present invention to be excellent in corrosion resistance.

C, N, O, and S: These elements were contained in an amount of 100 ppm in total number as inevitable impurities in the conventional Fe-Cr alloy, but in the alloy of the present invention, 100 ppm or less, preferably 85 ppm or less.

This reduction in the total amount of these elements is essential for the purpose of improving the corrosion resistance of the present invention.

The object of the present invention containing a large amount exceeding 100 ppm is not achieved.

Their basis is evident in FIGS.

P: The alloy of the present invention contains 0.01 to 1.0% by weight, preferably 0.015-0.3% by weight of P.

By containing P in the above range, excellent corrosion resistance is imparted to the alloy of the present invention.

However, the content exceeding 1.0% by weight is not preferable because not only the corrosion resistance decreases, but also the toughness decreases, resulting in manufacturing problems.

Since the Fe-Cr alloy of the 1st aspect of this invention which satisfy | fills the total amount and P content of Cr containing fragrance | flavor C, N, O, and S above is excellent in corrosion resistance, it is used suitably for the use of building exterior materials, vehicle exterior materials, etc. do.

(Second aspect)

In addition to the above components of the first embodiment, the compositions of Al, Si, and Mn added as deoxidizers are added.

That is, the ingot of the above-described components sufficiently achieves the object of the present invention even if the amounts of Al, Si, and Mn excessively provided are as follows.

Al: 1.0 weight% or less Preferably, it is 0.5 weight% or less.

Si: 1.0 wt% or less Preferably, 0.8 wt% or less,

Mn: 1.0 wt% or less Preferably, 0.7 wt% or less,

It is not preferable because the deoxidation effect contained above the above range is saturated.

Since it is excellent in the corrosion resistance of the Fe-Cr alloy of the 2nd aspect of this invention which satisfy | fills the above, it is used suitably for the use like 1st aspect.

(Third aspect)

In addition to the conditions of the first or second aspect, at least one selected from Ti, Nb, V, Zr, Ta, W, and B satisfies the following formula (I), preferably the following formula (I '). It contains an amount to make.

0.01 wt% Ti + Nb + Zr + V + Ta + W + 20B 1.0 wt%... … … … … (One)

0.03% by weight Ti + Nb + Zr + V + Ta + W + 20B 0.5% by weight … … … … (One')

Even if these elements are not added, an alloy having excellent corrosion resistance can be obtained. However, by satisfying the above-described range, an alloy excellent in corrosion resistance at the grain boundary is obtained, and corrosion resistance of the welded portion is improved.

However, excessive content of these elements is not preferable because workability is lowered by solid dissolution strengthening of the additive element body.

It is preferable that content of each element is the following range for the same reason.

Ti: 0.01-0.5 wt%

Zb: 0.01-0.5% by weight

Zr: 0.01-0.5% by weight

V: 0.01-0.5 wt%

Ta: 0.01-0.5 wt%

W: 0.01-0.5 wt%

B: 0.0003-0.1 wt%

The Fe-Cr alloy according to the third aspect of the present invention which satisfies the above is excellent in corrosion resistance and, again, excellent in corrosion resistance at the intergranular interface, so that the Fe-Cr alloy is suitably used for an exterior material, particularly a member to be welded.

(Fourth aspect)

In addition to the conditions of the first and second aspects,

Mo: 0.05-20% by weight, preferably 0.1-6.0% by weight.

Even if Mo is not added, an alloy having excellent corrosion resistance can be obtained. However, an alloy having improved hole corrosion resistance and weather resistance is obtained again by satisfying the above range.

Excessive blending in excess of 20% by weight is not preferable because the material is hardened and the toughness of the parent material is lowered.

Since the Fe-Cr alloy of the 4th aspect of this invention which satisfy | fills the above is excellent in corrosion resistance, and also excellent in corrosion resistance of a hole corrosion resistance again, it is used suitably for a hot water engine body etc.

(The fifth aspect)

In particular, the conditions of the 3rd aspect which is excellent in weld corrosion resistance are added to the conditions of the 4th aspect which are especially excellent in corrosion resistance to a hole.

That is, in addition to the conditions of the first or second aspect,

Mo: 0.05-20% by weight, preferably 0.1-6.0% by weight, and at least one member selected from Ti, Nb, V, Zr, Ta, W and B portion is preferably formula (I) Preferably it contains the amount which satisfy | fills following formula (I ').

0.01 wt% Ti + Nb + Zr + V + Ta + W + 20B 1.0 wt%... … … … … (One)

0.03% by weight Ti + Nb + Zr + V + Ta + W + 20B 0.5% by weight … … … … (One')

Since the preferred range of each individual element of Ti, Nb, V, Zr, Ta, W and B is as shown in the 3rd aspect, description is abbreviate | omitted.

The Fe-Cr alloy according to the fifth aspect of the present invention which satisfies the above is excellent in the corrosion resistance of the welded part in addition to the corrosion resistance of the parent material, which is advantageous for the member to be welded.

(6th aspect)

In addition to the first, second, third, fourth or fifth aspect, at least one selected from Ni, Co and Cu satisfies the following formula (2), preferably the following formula (2 '). It contains.

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

0.05 wt% Ni + Co + 2Cu 5% by weight. … … … … (2')

Even if these elements are not added, an alloy having excellent corrosion resistance is obtained, but by adding a specific amount of one or more of these elements, an alloy with improved acid resistance and weather resistance is obtained again.

When the compounding quantity of Ni, Co, and Cu is less than the said range, since acid resistance will fall, when there are many, the manufacturability of an alloy will fall.

In addition, preferable contents of Ni, Co, and Cu are as follows, and the reason is as above-mentioned.

Ni: 0.05-5.0 wt%

Co: 0.05-5.0 wt%

Cu: 0.05-2.5 wt%

The Fe-Cr alloy of the sixth aspect of the present invention, which satisfies the above, is excellent in corrosion resistance as well as acid resistance, and a chemical process is advantageously used for construction and the like.

(7th aspect)

In addition to the first, third, fourth or fifth aspect, at least one selected from Al, Si, and Mn is contained in an amount that satisfies the following formula (3), preferably the following formula (3 '). .

1.0 wt% 3Al + 2Si + Mn 50 wt% … … … … … … … (3)

3.0 wt% 3Al + 2Si + Mn 20 wt% … … … … … … … (3 ')

Since the 7th aspect especially adds Al, Si, and Mn for the purpose of the improvement of oxidation resistance, the objective differs essentially from the 2nd aspect.

Even if these elements are not added, an alloy having excellent corrosion resistance can be obtained, but by adding a specific amount of one or more of these elements, an alloy with improved oxidation resistance is obtained again.

Excessive content exceeding 50% by weight is to be avoided because the oxide inclusions are interspersed in the alloy, the manufacturability is lowered, and it is difficult to produce the alloy.

Preferred contents of each individual element and the reason thereof are as follows.

Al: 0.1-10.0 wt%

It is effective at less than 0.1% by weight, but it is not significant.

If it exceeds 10.0% by weight, a decrease in manufacturability is noticeable.

Si: 0.1-10.0 wt%

It is effective at less than 0.1% by weight, but it is not significant.

When it exceeds 10.0 weight%, the fall of manufacturability will appear notably.

Mn: 0.1-20.0 wt%

It is effective at less than 0.1% by weight, but not significant.

If it exceeds 20% by weight, a decrease in manufacturability will be noticeable.

The Fe-Cr alloy according to the seventh aspect of the present invention which satisfies the above is excellent in corrosion resistance and, in addition, excellent in oxidation resistance at high temperatures, and thus is advantageously used for automobile exhaust gas materials.

(Eighth aspect)

In particular, the conditions of the 6th aspect excellent in acid resistance are added to the conditions of the 7th aspect which are especially excellent in oxidation resistance.

That is, in addition to the first, third, fourth or fifth aspect, at least one selected from Ni, Co and Cu satisfies the following formula (2), preferably the following formula (2 '). At the same time, at least one selected from Al, Si, and Mn is contained in an amount that satisfies the following formula (3), preferably the following formula (3 ').

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

0.05 wt% Ni + Co + 2Cu 5% by weight. … … … … … (2')

1.0 wt% 3Al + 2Si + Mn 50 wt% … … … … … … … (3)

3.0 wt% 3Al + 2Si + Mn 20 wt% … … … … … … … (3 ')

Since the reason for limitation of the preferable range and component range of each individual element is as showing in 6th and 7th aspect, description is abbreviate | omitted.

The alloy of the present invention shown in the first to eighth aspects is obtained by dissolving and casting a high purity raw material by an electrolytic method or the like under a high vacuum.

At this time, Al, Si, and Mn can be used as the deoxidation material.

After dissolution, a conventional manufacturing process is performed, that is, melt casting-hot rolling-annealing-pickling-cold rolling-annealing-(acid washing)-(material adjusting rolling).

Moreover, it is preferable that the alloy of this invention is Fe other than the component mentioned above.

However, even if one or more types of elements, such as Ca, Mg, REM (rare earth element) Pb, Bi, Se, and Te, are contained less than 1% of total amount, the effect is acquired sufficiently.

Again, the alloy of the present invention has a sufficient effect, whether it is used in a hot rolled annealing plate or a cold rolled annealing plate, and the final surface finish is any of 2D, 2B, BA, HL and polishing finish. Fully the effect is obtained.

EXAMPLE

Next, as an experimental result, this invention is demonstrated concretely.

Small ingots of 30 kg of various Fe-Cr alloys of chemical composition shown in Table 1 were melt cast at an ultra-high vacuum 50 kg high frequency furnace.

In melt casting, in order to suppress the total amount of S, C, N, and O to 100 ppm or less, an ultra-high vacuum furnace having a maximum attained vacuum of 10 ^-1 torr at room temperature was used, and a high-purity raw material was used for the raw material. .

The crucible was washed several times with ultra-high purity iron in advance for the purpose of suppressing the incorporation of impurity elements from the crucible as much as possible, and then dissolved using strong stirring.

Each ingot was subjected to annealing for the purpose of recrystallization after removing 1 cm of the surface and heating it uniformly at an optimal temperature selected at a temperature range of 1100-1250 ° C. for 1 hour.

Thereafter, the carburized nitride layer on the back was cut off, and cold rolling and recrystallization annealing were repeated once or twice, and finally, a cold rolled annealing plate having a thickness of 0.7 mm was used for the test.

Moreover, the back layer was polished and removed as needed before providing to a test.

The test piece adjusted by the above method was tested for various corrosion resistance by the following method.

Weathering test

After a year of atmospheric exposure testing in the coastal industrial zone,

(1) The appearance of the test piece was observed and the degree of rust formation was classified into the following five levels and evaluated.

1: No rust

2: very light stain stain

3: Light degree of stain corrosion

4: Spot red rust occurs with stain shape corrosion

5: Red rust tends to occur

(2) The glossiness retention rate was measured using a gloss meter (HG-246) manufactured by Suga Test Instruments, and the ratio of gloss before and after the atmospheric exposure was determined as the glossiness retention rate.

Gloss retention rate (%) = {Gs (20) (after exposure) / Gs (20) (before exposure)} × 100

(Cross Particle Corrosion Test)

The corrosion resistance of the intergranular interface was evaluated by the sulfuric acid and copper sulfate test of stainless steel specified by Japanese Industrial Standard (JIS) G 0575.

(Pore corrosion test)

The hole corrosion potential in accordance with Japanese Industrial Standard (JIS) G0577 was measured. The hole corrosion potential was represented by a potential that reached a current density of 10 μA / cm ² .

(Acid resistance test)

The corrosion loss was measured after immersing the test piece in boiling 0.5% Hcl aqueous solution for 18 hours, and the evaluation of acid resistance was evaluated in the following four steps.

◎: Corrosion degree less than 0.1g / m ² hr

○: Corrosion degree 0.1-1 g / m ² hr

△: corrosion degree 1-38 / m ² hr

X: Corrosion degree 38 / m ² hr or more

(Oxidation resistance test)

Repeated oxidation test with 1 cycle of heating for 12 minutes and cooling for 10 minutes at 1075 ° C in a bet, and measuring the weight change every 25 cycles until the cycle of abnormal oxidation (oxidation weight is 5.0mg / m ² The number of cycles over time) was measured.

Table 1

Chemical Composition of the Inventive and Comparative Examples

Unit: Weight% * Table ppm, α = C + N + O + S, β = Ti + Nv + Zr + V + W + Ta + 2ob

γ = Ni + Co + 2Cu, δ = 3Al + 2Si + Mn

The experimental results are described below.

[Experiment Result 1]

Tables 2, 3 and 4 show the weather resistance test results of Fe-20%, Cr alloy, Fe-11% Cr alloy and Fe-40% Cr alloy, respectively.

[Table 2]

Fe-20% Cr class

Table 3

Fe-11% Cr Alloy

Table 4

Fe-40% Cr Alloy

It is clear from Table 2, Table 3, and Table 4 that the alloy of the present invention is remarkably excellent in weather resistance.

The large amount of C, N, O, and S exceeding 100 ppm and the P outside of the present invention do not show excellent weather resistance.

Table 5 also shows the weather resistance test results of the Fe- (40-20)% Cr-0.1% P alloy.

Table 5

Fe- (4 ~ 20)% Cr-0.1% P Alloy

The alloy of the present invention having a Cr content of at least 5% by weight exhibits excellent weather resistance.

Comparative alloy 6 having a Cr content of 4.8% by weight has a large red rust and a marked drop in gloss retention, and thus cannot be said to exhibit excellent weather resistance.

[Experiment 2]

Table 6 shows the weather resistance test results for the Fe-20% Cr-0.02% P alloy.

Table 6

Fe-20% Cr-0.02% P Alloy

For example, even if Al, Si, and Mn used in deoxidation materials are mixed, if the content is 10% or less, it is obvious that the Cr content is combined with the conditions of the total amount P content of C, N, O and S to obtain sufficient acid resistance. Do.

[Experiment Result 3]

Table 7 shows Fe-11% Cr-0.1% P alloy (C + N + O + S) The results of the weather resistance test and the particle interfacial corrosion test performed on 100 ppm) are shown.

Table 7

Fe-11% Cr-0.1% P (C + N + O + S 100 ppm)

0.01 wt% of the value of β = T + Nb + Zr + V + Ta + W + 20B

If it is below, it is clear that the total amount of C, N, O, and S of Cr content combines with the conditions of P content, and is excellent not only in a weather resistance but also excellent in intergranular corrosion resistance.

[Experiment Result 4]

Table 8 shows the results of the weather resistance test and the hole corrosion resistance test of the Fe-20% Cr- (0.01-0.4)% P- (0.001-6)% Mo alloy.

Table 8

Fe-20% Cr- (0.01 ~ 0.4)% P- (0.001 ~ 6)% Mo Alloy

In addition to the conditions of the total content P content of Cr content C, N, O, and S, it is clear that the steel of this invention which is Mo content is 0.05 weight% or more is excellent in hole corrosion resistance.

Since the total amount of C, N, O and S exceeds 100 ppm, many comparative alloys 7 are inferior to not only weather resistance but also hole corrosion resistance.

[Experiment 5]

Table 9 shows the results of the weather resistance test, the particle interface corrosion resistance test, and the corrosion resistance test of the alloys 26 and 27.

Table 9

In addition to the conditions of the total content P content of Cr content C, N, O, and S, the alloy of the present invention which satisfies the range of Mo content Ti + Nb + Zr + V + W + 20B is in addition to weather resistance, and has a corrosion resistance at the intergranular interface. And also excellent in corrosion resistance to pores.

[Experimental Result 6]

Table 10 shows the results of the weather resistance test and the acid resistance test of Fe-20% Cr-0.02% P alloy (C + N + O + S <100ppm).

Table 10

Fe-20% Cr-0.02 P Alloy (C + N + O + S <100ppm)

It is clear from the results of Table 10 that the acid resistance is improved when the value of Ni + Co + 2Cu exceeds 0.01% by weight.

[Experiment Result 7]

Table 11 shows the results of the weather resistance test resistance oxidation test for Fe-20% Cr-0.015% P alloy (C + N + O + S <100 ppm).

Table 11

Fe-20% Cr-0.015% P Alloy (C + N + O + S <100ppm)

It is clear from the results of Table 11 that the oxidation resistance is improved when the value of 3Al + 2Si + Mn exceeds 1.0% by weight.

As indicated above, the Fe-Cr alloy of the present invention is preferably used in the overall application of the Fe-Cr alloy because of excellent corrosion resistance in various aspects.

Claims (7)

High corrosion resistance, characterized in that the Cr content is 5% by weight or more, the total amount of C, N, O, and S is 100 ppm or less, the P content is 0.01-1.0% by weight, and the remainder is Fe and unavoidable impurities. Cr alloy. Cr content is 5 weight% or more, the total amount of C, N, O, and S is 100 ppm or less, P content is 0.01-1.0 weight%, Furthermore, 1 type chosen from Ti, Nb, V, Zr, Ta, W, or B The Fe-Cr alloy excellent in corrosion resistance containing the amount which satisfy | fills the following Formula (1), and consists of remainder Fe and an unavoidable impurity. 0.01 wt% <Ti + Nb + Zr + V + Ta + W + 20B <1.0 wt%. … … … … (One) Cr content is 5 weight% or more, the total amount of C, N, O, and S is 100 ppm or less, P content is 0.01-1.0 weight%, Furthermore, 1 type chosen from Ti, Nb, V, Zr, Ta, W, or B The Fe-Cr alloy excellent in corrosion resistance which contained the quantity which satisfy | fills the following Formula (1), and adds 0.05-20 weight% of Mo to it, and became remainder Fe and an unavoidable impurity. 0.01 wt% <Ti + Nb + Zr + V + Ta + W + 20B <1.0 wt%. … … … … (One) Cr content is 5 weight% or more, the total amount of C, N, O, and S is 100 ppm or less, P content is 0.01-1.0 weight%, Furthermore, 1 type chosen from Ti, Nb, V, Zr, Ta, W, or B The above is contained in an amount satisfying the following formula (1), and at least one selected from Ni, Co, and Cu is added in an amount satisfying the following formula (2), and the remainder is made of Fe and unavoidable impurities. Fe-Cr alloy excellent in corrosion resistance. 0.01 wt% <Ti + Nb + Zr + V + Ta + W + 20B <1.0 wt%. … … … … (One) 0.01 wt% ≦ Ni + Co + 2Cu ≦ 6 wt%. … … … … (2) Cr content is 5 weight% or more, the total amount of C, N, O, and S is 100 ppm or less, P content is 0.01-1.0 weight%, Furthermore, 1 type chosen from Ti, Nb, V, Zr, Ta, W, or B The above content is contained in an amount satisfying the following formula (1), and at least one selected from Al, Si, and Mn is added in an amount satisfying the following formula (3), and the remainder is made of Fe and unavoidable impurities. Fe-Cr alloy excellent in corrosion resistance. 0.01 wt% <Ti + Nb + Zr + V + Ta + W + 20B <1.0 wt%. … … … … (One) 1.0 wt% ≦ 3Al + 2Si + Mn ≦ 50 wt%. … … … … … … … (3) Cr content is 5 weight% or more, the total amount of C, N, O, and S is 100 ppm or less, P content is 0.01-1.0 weight%, Furthermore, 1 type chosen from Ti, Nb, V, Zr, Ta, W, or B The above content is contained in an amount that satisfies the following formula (1), and Mo is added in an amount of 0.05 to 20% by weight, and again an amount of one or more selected from Ni, Co and Cu is satisfied in the formula (2) A Fe-Cr alloy excellent in corrosion resistance, which is added, and is made of residual Fe and unavoidable impurities. 0.01 wt% <Ti + Nb + Zr + V + Ta + W + 20B <1.0 wt%. … … … … (One) 0.01 wt% ≦ Ni + Co + 2Cu ≦ 6 wt%. … … … … (2) Cr content is 5 weight% or more, the total amount of C, N, O, and S is 100 ppm or less, P content is 0.01-1.0 weight%, Furthermore, 1 type chosen from Ti, Nb, V, Zr, Ta, W, or B The above content is contained in an amount that satisfies the following formula (1), and Mo is added in an amount of 0.05 to 20% by weight, and at least one kind selected from Al, Si, and Mn is further satisfied A Fe-Cr alloy excellent in corrosion resistance, which is added, and is made of residual Fe and unavoidable impurities. 0.01 wt% <Ti + Nb + Zr + V + Ta + W + 20B <1.0 wt%. … … … … (One) 1.0 wt% ≦ 3Al + 2Si + Mn ≦ 50 wt%. … … … … ()