JPH06192792A - Boron-containing stainless steel with high corrosion resistance - Google Patents

Abstract

PURPOSE:To produce a stainless steel having neutron absorption capacity higher than that of a conventional high B stainless steel, excellent in corrosion resistance and hot rollability, and suitable for austenitic stainless steel for neutron shielding. CONSTITUTION:The boron-containing stainless steel having a composition consisting of, by weight, <=0.02% C, <=0.5% Si, <=2% Mn, 10-22% Ni, 18-26% Cr, <=3.0% B, <=0.1% Mg, <=0.5% Al, 0.05-1.0% Gd or/and 0.1-5%, independently or in total, of one or more elements among Ti, Zr, and Nb, and the balance Fe with impurities is obtained. Further, <=1wt.% each of one or more elements among Cd, Sm, and Eu or/and 0.1-5wt.%, independently or in total, of one or more elements among Mo, W, and V are incorporated.

Description

Detailed Description of the Invention

[0001]

This invention relates to a container for transporting nuclear fuel,
The present invention relates to highly corrosion-resistant stainless steel used as a neutron shielding material for nuclear-related equipment such as spent nuclear fuel storage racks.

[0002]

2. Description of the Related Art Since B (boron) has a large neutron capture cross section, austenitic stainless steel containing B is used as a neutron control material and a shielding material. As such a steel, SUS 304 series stainless steel containing B in an amount of about 1% is disclosed in, for example, Japanese Patent Publication No. 57-45464. In addition, since B precipitates as (Cr, Fe) ₂ B, the amount of Cr in the base material decreases and corrosion resistance deteriorates. Therefore, a B-containing stainless steel with an increased Cr concentration has also been proposed (Japanese Patent Laid-Open Publication No. Sho.
62-222049). However, if the Cr content of the base material is significantly increased, the Ni content must be increased in order to maintain the austenite structure, which increases the manufacturing cost.

By the way, in recent years, in order to miniaturize the rack for storing spent nuclear fuel, further thinning of stainless steel as a raw material has been demanded, and it is necessary to develop a steel material having high neutron absorption ability and excellent corrosion resistance. It's coming. However, when the B content in the stainless steel is increased, the B compound is precipitated and the corrosion resistance is lowered as described above, and the hot workability is significantly deteriorated, and cracks occur during hot rolling. That is,
During the hot rolling, the temperature of the plate decreases as the rolling progresses, so that the B-added steel causes edge cracking.
For this reason, there arises a problem of a decrease in yield, and if it is attempted to avoid this, a heat treatment such as reheating is required, and the manufacturing cost increases.

In order to prevent cracking due to temperature drop during hot rolling, for example, a method of hot rolling after covering the B-containing stainless steel with an iron cylinder (JP-A-61-2017)
No. 26) has been proposed, but a large number of man-hours are required such as closely surrounding the surface of a steel ingot shaped in a rectangular shape with an iron cylinder such as a welding assembly and crimping by forging.

The absorption of neutrons by B is due to ¹⁰ B having an atomic weight of 10 contained in natural B in an amount of about 20 atomic%. The neutron capture cross section of ¹⁰ B (about 3800 b) is contained in natural B in an amount of about 80 atomic%. It is about 10 ⁶ times larger than the ¹¹ B neutron capture cross section (5 ± 3 mb). Therefore, if B having a higher content rate of ¹⁰ B is used as B added to the stainless steel, the neutron absorption capacity is higher than that when natural B is added even with the same addition amount. However, the atomic weight is 1
Separation of only different isotopes is difficult and costly.

[0006]

SUMMARY OF THE INVENTION The present invention is based on the conventional high B
It is an object of the present invention to provide a stainless steel which has a higher neutron absorption capacity than stainless steel and is also excellent in corrosion resistance and hot rolling property.

[0007]

[Means for solving the problem] High neutron absorption capacity ¹⁰
To produce high B stainless steel with only B added,
As described above, at present, it is difficult in terms of technology and cost.

As an element having a high neutron absorption capacity, that is, a large neutron capture cross section, 12.26 atomic% of natural Cd (cadmium) is present at ¹¹³ Cd (neutron capture cross section: 2000
0b), 13.83% atomic% in natural Sm (samarium) ¹⁴⁹ Sm (41000b), Eu (europium, 4100b), Gd
(Gadolinium, 49000b) and the like are known, but the present inventors have added these elements to stainless steel, and further examined the hot rolling property and the corrosion resistance by changing the addition amount of other alloy elements. , Gd has the highest neutron absorption capability, and also has the function of stabilizing the passive film to improve the corrosion resistance and further reducing the deterioration of hot rolling property due to B. In addition, the numerical value showing the above-mentioned neutron capture cross section is shown in "Handbook of Chemistry and Physics".
− A Ready-Reference Book of Chemical and Physical
Data, 57th Edition (1976-1977) "(Published by C
RC PRESS) B-271, B-297, B-311 to 314 are approximate numbers.

When the B content in stainless steel is increased, the amount of (Cr, Fe) ₂ B precipitates increases, and the corrosion resistance deteriorates.
Corrosion resistance is achieved by adding Ti, Zr or Nb, which is easy to form a compound with B, as an alloy component, and forming compounds such as TiB ₂ , ZrB ₂ or NbB _{2 in the} steel to suppress the precipitation amount of (Cr, Fe) ₂ B. It has been confirmed that can improve.

Furthermore, the corrosion resistance can be further improved by adding Mo, W or V.

The present invention has been made on the basis of the above findings, and the gist thereof resides in stainless steels of the first series to the third series shown in (1) to (3) below. In the following description, the basic composition and the components of the first to fourth groups mean the following compositions and components. Further, "%" of the alloying element means "wt%".

Basic composition: C: 0.02% or less, Si:
0.5% or less, Mn: 2% or less, Ni: 10-22%, Cr: 18-26
%, B: 2.0% or less, Mg: 0.1% or less, Al: 0.5% or less, and the balance Fe and unavoidable impurities.

Group 1 components; Gd: 0.05 to 1.0% Group 2 components; Cd: 1% or less, Sm: 1% or less and E
u: 1% or less Group 3 ingredients; Mo, W and V, alone or in total
0.1-5% Group 4 ingredients; Ti, Zr and Nb, alone or in total
0.1 to 5% Stainless steel of the first series To the stainless steel having the above basic composition, the components of the first group (Gd: 0.05 to 1.0%) are added as essential components, and further, if necessary, of the second group. Ingredients (Cd: 1% or less, Sm: 1
% Or less and Eu: 1% or less), or /
And a highly corrosion resistant boron-containing stainless steel containing one or more of the third group components (Mo, W and V, alone or in total 0.1 to 5%).

Second Series Stainless Steel In addition to the stainless steel having the above basic composition, at least one of the fourth group of components (Ti, Zr and Nb, alone or 0.1 to 5% in total) is an essential component. In addition, if necessary, the components of the second group (Cd: 1% or less, Sm: 1% or less and
Eu: 1% or less), and / or third group components (Mo, W and V, alone or in total, 0.1 to 5)
%) Highly corrosion-resistant boron-containing stainless steel containing one or more of

Third Series Stainless Steels In addition to the stainless steels having the above basic composition, the first group of components (Gd: 0.05 to 1.0%) and the fourth group of components (Ti, Zr and Nb, alone or in total 0.1). ~ 5%) as an essential component, and if necessary, in the second group components (Cd: 1% or less, Sm: 1% or less and Eu: 1% or less) One or more, and / or third group components (M
High corrosion resistant boron-containing stainless steel containing one or more of o, W and V, alone or in total of 0.1 to 5%).

[0016]

The function and effect of the constituents of the stainless steel of the present invention and the reason for limiting the content thereof will be described below.

First, the elements constituting the basic composition will be described.

C: C precipitates a carbide of Cr (Cr ₂₃ C ₆ ) at the grain boundary due to the heat effect at the time of welding and forms a portion having a low Cr concentration around the carbide, thereby deteriorating the corrosion resistance at the grain boundary. If the C content exceeds 0.02%, the tendency becomes remarkable.
% Or less.

Si and Mn: Both Si and Mn are effective as deoxidizing elements. However, in both cases, the weldability and cleanliness are deteriorated if the added amount is too large, so their contents must be 0.5% or less and 2% or less, respectively. The lower limit is not specified, but if the content is too small, deoxidation will not be sufficiently carried out, so it is desirable to set it to 0.05% or more and 0.5% or more respectively.

Ni: Ni is an element necessary for stabilizing the austenite structure, but if it is less than 10%, its effect is not sufficient, while if it exceeds 22%, it has a stabilizing effect on the austenite structure. Is saturated and only leads to high costs. Therefore, the content is 10 to 22%.

Cr: Cr is an essential element for ensuring high corrosion resistance of stainless steel. If it is less than 18%, the required corrosion resistance cannot be obtained. On the other hand, if it exceeds 26%, it is necessary to increase the amount of Ni added, which leads to an increase in cost and the workability deteriorates due to the increase in the Cr content.

Therefore, the content is 18 to 26%.

B: B is an element necessary for neutron absorption, but if it is added in an amount exceeding 3.0%, the hot rolling property is significantly deteriorated, so the upper limit is made 3.0%. The lower limit is not specified, but in order to enhance the neutron absorption capacity of steel, 0.1
% Or more is desirable.

Mg: By adding a small amount of Mg, the hot forgeability becomes very good. However, even if the content exceeds 0.1%, the effect is saturated, so the content should be 0.1% or less.

The lower limit is not particularly limited, but it is desirable to contain 0.01% or more in order to exert the effect.

Sol.Al: sol.Al is also effective as a deoxidizing element like Si and Mn, but if it exceeds 0.5%, the cleanliness of the alloy is lowered, so its content is limited to 0.5% or less. .
On the other hand, if the content is too small, the deoxidizing effect will not be sufficient, so it is desirable to contain 0.05% or more.

The above-mentioned first series of stainless steel is a stainless steel obtained by adding Gd (0.05 to 1.0%), which is the first group of components, as an essential component to the stainless steel having the components constituting the above basic composition. Is.

Gd has the effects of increasing the neutron absorption capacity of the steel, stabilizing the passivation film to improve the corrosion resistance, and reducing the deterioration of hot rolling property due to B. However, if the content is less than 0.05%, these effects are not sufficient, while if it exceeds 1.0%, Gd reacts with Fe, Cr, and Ni to form a eutectic compound with a low melting point, which causes forging. Therefore, the content is 0.05 to 1.0.
%.

Therefore, the first series stainless steel containing Gd as an essential component has not only a high neutron absorption capacity but also a good corrosion resistance and an excellent hot rolling property, and as shown in Examples described later, , Almost no cracking of the ears was observed during rolling.

As the first series of stainless steel, in addition to this stainless steel, one of the second group components (Cd: 1% or less, Sm: 1% or less and Eu: 1% or less) Stainless steel containing the above, stainless steel containing 0.1 to 5% of one or more of the third group components (Mo, W and V) alone or in total, and the second group components (Cd :
1% or less, Sm: 1% or less and Eu: 1% or less)
Included are stainless steels containing 0.1 to 5% of one or more kinds and one or more kinds of the third group components (Mo, W and V) alone or in total.

The components of the second group, Cd, Sm and Eu, are 1
Although the neutron absorption capacity per atom is inferior to Gd, it is an element with high neutron absorption capacity. However, if added in a large amount, the cost will increase and the hot forgeability will deteriorate, so the content of each of these is made 1% or less. The contents of Cd, Sm, and Eu are all natural element contents, and for Cd and Sm, as described above,
Since it contains ¹¹³ Cd and ¹⁴⁹ Sm with large neutron capture cross sections, the neutron capture cross sections of natural elements are 2450b for Cd and 5820b for Sm.

The components of the third group, Mo, W and V
Is an element effective in improving corrosion resistance, particularly pitting corrosion resistance.
However, if the content of one or more of these elements, alone or in total, is less than 0.1%, the passivation film formed on the surface of the steel is not strengthened and pitting corrosion resistance cannot be sufficiently improved. On the other hand, if the content of one or more of these elements alone or in total exceeds 5.0%, not only the effect of improving the pitting corrosion resistance is saturated, but also the hot workability is significantly deteriorated. The content is individually or totally 0.1 to 5%.

Therefore, one or more of the second group of components (Cd: 1% or less, Sm: 1% or less and Eu: 1% or less) were added to the stainless steel containing Gd as an essential component. The neutron absorption capacity of the stainless steel is further enhanced, and the stainless steel containing one or more of the third group components (Mo, W and V) alone or in a total of 0.1 to 5% has corrosion resistance (especially pitting corrosion resistance). ) Is further improved. 1 of the 2nd group components
Stainless steel containing at least one of the above-mentioned components and at least one of the components of the third group has an improved neutron absorption capacity and improved corrosion resistance (particularly pitting corrosion resistance).

The above-mentioned second series of stainless steels are the same as the stainless steels having the constituents of the above-mentioned basic composition but also the constituents of the fourth group of Ti, Zr and Nb (alone or in total).
It is a stainless steel containing at least one of 0.1 to 5%) as an essential component.

The components of the fourth group, Ti, Zr and Nb, are all combined with B to form TiB ₂ , ZrB ₂ or NbB in the steel.
It has a function of improving the corrosion resistance by to produce a compound such as ₂ (Cr, Fe) to reduce the amount of precipitation of ₂ B. However, if the content is alone or in total less than 0.1%, the effect is not sufficient. On the other hand, if it is contained alone or in total more than 5%, not only the cost increases, but also the hot workability deteriorates. Therefore, the content of these elements is 0.1-5% individually or in total.

Accordingly, the second series of stainless steels containing at least one of Ti, Zr and Nb (alone or 0.1 to 5% in total) as an essential component forms (Cr, Fe) ₂ B. Is suppressed and general corrosion resistance and intergranular corrosion resistance are enhanced, and crevice corrosion resistance and pitting corrosion resistance are also improved, resulting in good corrosion resistance.

As the second series of stainless steel, in addition to this stainless steel, one of the components of the second group (Cd: 1% or less, Sm: 1% or less and Eu: 1% or less) Stainless steel containing the above, stainless steel containing 0.1 to 5% of one or more of the third group components (Mo, W and V) alone or in total, and the second group components (Cd :
1% or less, Sm: 1% or less and Eu: 1% or less)
Included are stainless steels containing 0.1 to 5% of one or more kinds and one or more kinds of the third group components (Mo, W and V) alone or in total.

The stainless steel containing at least one of the second group components (Cd: 1% or less, Sm: 1% or less and Eu: 1% or less) has a further enhanced neutron absorption capability, Corrosion resistance (particularly pitting corrosion resistance) of the stainless steel containing 0.1 to 5% of one or more of the group components (Mo, W and V) alone or in total is further improved. 1 of the 2nd group components
Stainless steel containing at least one of the above-mentioned components and at least one of the components of the third group has an improved neutron absorption capacity and improved corrosion resistance (particularly pitting corrosion resistance).

The above-mentioned third series of stainless steels is the same as the stainless steels having the components constituting the above-mentioned basic composition, but Gd (0.05 to 1.0%) which is the first group component and Ti which is the fourth group component. , Zr and Nb (alone or 0.1 to 5% in total) are stainless steels to which one or more of them are added as an essential component. This stainless steel has high neutron absorption capability, excellent hot rolling property, and good corrosion resistance.

As the third series of stainless steel, in addition to this stainless steel, one of the components of the second group (Cd: 1% or less, Sm: 1% or less and Eu: 1% or less) Stainless steel containing the above, stainless steel containing 0.1 to 5% of one or more of the third group components (Mo, W and V) alone or in total, and the second group components (Cd :
1% or less, Sm: 1% or less and Eu: 1% or less)
Included are stainless steels containing 0.1 to 5% of one or more kinds and one or more kinds of the third group components (Mo, W and V) alone or in total. These stainless steels are
As in the case of the series stainless steel and the second series stainless steel, the neutron absorption capacity is further enhanced and the corrosion resistance (particularly pitting corrosion resistance) is further improved, or the neutron absorption capacity is further improved and the corrosion resistance (particularly pitting resistance) is improved. Food habit)
Is improved.

[0041]

Example 1 This is an example for confirming the effect of the first series stainless steel, that is, the stainless steel containing Gd as an essential component.

Steels each having the chemical composition shown in Table 1 were melted by vacuum melting in an amount of 30 kg, forged, hot-rolled and cold-rolled, and then solution heat treated (heated at 1100 ° C. and water-cooled).
Sensitized at 650 ℃ for 2 hours, and used as test materials. Neutron absorption capacity, hot forgeability, hot rollability and corrosion resistance of these test materials (crevice corrosion reduction and general corrosion · Intergranular corrosion rate) was investigated.

Regarding the neutron absorption capacity, B
Since B-containing stainless steel containing about 0.5% is used as a rack material for nuclear fuel storage, the neutron absorption capacity of comparative steel No. 29 containing 0.53% B is set to 1, and B, Gd,
It was calculated from the neutron capture cross section of each element, taking into account the contents of Cd, Sm and Eu.

Regarding hot forgeability, whether or not cracks were generated by forging, and regarding hot rollability, a plate with a thickness of 30 mm was heated at 1000 ° C and rolled to a thickness of 7 mm by ear cracking. The occurrence of cracks and the length of cracks were investigated.

Regarding crevice corrosion, from the above-mentioned sample materials,
As shown in Fig. 1 (a) and (b), 3 mm (thickness) × 20
mm × 30 mm and 3 mm (thickness) × 12 mm × 30 mm corrosion test pieces were taken, and these test pieces were taken as shown in (c) of FIG.
After forming a metal / metal gap by overlapping with a Teflon bolt and nut, a crevice corrosion test was performed to determine the corrosion weight loss. For crevice corrosion test, test piece is 2200ppmH ₃ BO ₄ +
500PpmCl ^- in an aqueous solution of, 80 ° C., 500 with air saturated conditions
It was performed by soaking for a time. Regarding general corrosion and intergranular corrosion, sulfuric acid specified in JIS G 0575 using a test piece of 3 mm (thickness) × 10 mm (width) × 40 mm (length)
A copper sulfate corrosion test was conducted to determine the corrosion rate.

The survey results are shown in Table 2.

Regarding the effect of Gd, when compared with the same B content, it is as in Comparative Steel No. 35 (B: 0.52%, Gd: 0.01%).
When 0.01% of Gd is included, the comparative steel No. 29 is used as a standard.
No increase in neutron absorption capacity was observed with respect to (B: 0.53%, Gd: not added), but steel No. 1 of the present invention containing 0.05% or more of Gd (B: 0.52%, Gd: 0.07%) ), The neutron absorption capacity is 1.4 times higher, and the invention steel No. 27 (B:
0.51%, Gd: 0.32%) and No. 28 (B: 0.52%, Gd:
0.33%) increased 3.1 times and 3.2 times, respectively. Therefore, in order to increase the neutron absorption capacity, the content of Gd should be
It is necessary to set it to 0.05% or more. However, if the content exceeds 1.0%, cracking occurs during hot forging, making it impossible to forge (Comparative Steel Nos. 36 and 37). This is because the eutectic reaction occurs between Gd and Fe, Ni and Cr as described above.
It is considered that this is because a eutectic compound having a low melting point is produced.

When the addition amount of B is increased without adding Gd in order to enhance the neutron absorption ability, the cracking of the ears tends to occur during hot rolling, and the length of the cracking of the ears increases as the addition amount of B increases. growing. When B was added in an amount of more than 1%, a very large edge crack occurred (Comparative Steel No. 31-
No.34). In addition, since Cr ₂ B precipitates, the corrosion resistance deteriorated.

On the other hand, when the same neutron absorption capacity is given by adding Gd, for example, steel No. 5 of the present invention (B: 1.
10%, Gd: 0.47%) and comparative steel No. 33 (B: 2.64%, Gd:
No addition) or steel No. 6 of the present invention (B: 1.
62%, Gd: 0.46%) and comparative steel No. 34 (B: 3.21%, Gd:
As is clear from the comparison with (without addition), Comparative Steel No. 33
In No. 34 and No. 34, an ear crack having a crack length of more than 10 mm occurred, but in the steels No. 5 and No. 6 of the present invention, the B content can be kept low, so that the crack length is as small as 10 mm or less. It stayed in the crack. Moreover, when B is added, Cr ₂ B precipitates, and the amount of Cr decreases by that amount, but because the addition of Gd stabilizes the passive film, the corrosion rate in the sulfuric acid / copper sulfate test is small, and the corrosion resistance is high. Excellent in general corrosion resistance and intergranular corrosion resistance.

From the above results, it is understood that by containing 0.05 to 1% of Gd, the neutron absorption capacity of the steel can be increased, the corrosion resistance can be improved, and the deterioration of the hot rolling property due to B can be reduced.

When Cr content is less than 18% (Comparative Steel No. 3
0) or C is more than 0.02% (Comparative Steel No. 31),
The crevice corrosion weight loss was large, the corrosion resistance was poor, and when Al and Mg were not added (Comparative Steel No. 38), cracking occurred during hot forging.

When at least one of Cd, Sm and Eu is added (inventive steel Nos. 7 to 13), the neutron absorption capacity is such that these elements are not added and the contents of B and Gd are approximately It is further improved as compared with the case of the same level (steel No. 2 of the present invention).

When Mo, V and W are added alone or in combination (invention steel No. 11 to No. 26), these elements are not added (invention steel No. 2). The crevice corrosion weight loss is smaller than that of No. 1, and the corrosion resistance can be further improved.

[0054]

Example 2 This is a second series and a third series of stainless steels, that is, stainless steels containing at least one of Ti, Zr and Nb (single or a total of 0.1 to 5%) as an essential component, In addition, it is an example for confirming the effect of the stainless steel containing Gd and one or more of Ti, Zr and Nb (single or a total of 0.1 to 5%) as essential components.

Steels each having the chemical composition shown in Table 3 were melted by vacuum melting in an amount of 30 kg, forged, hot-rolled and cold-rolled, and then solution heat treated (heated at 1100 ° C. and then water-cooled).
The specimens subjected to sensitization treatment (650 ° C. × 2 hrs → air cooling) were subjected to neutron absorption capability, hot rollability and crevice corrosion reduction.

The neutron absorption capacity was calculated in the same manner as in Example 1 with the neutron absorption capacity of Steel No. 1 of the present invention containing 0.52% B being 1.

Regarding the hot rolling property, the heating temperature of the plate was set to 10
The presence or absence of ear cracks and the crack length were investigated under the same method and conditions as in Example 1 except that the temperature was 50 ° C.

Regarding crevice corrosion, the same test piece as in Example 1 was cut out from the above-mentioned test material, and 2200 ppmH ₃ BO _{4 was used.}
A crevice corrosion test was conducted under the same method and conditions as in Example 1 except that an aqueous solution of +1000 ppm Cl ⁻ was used as a test solution.
The corrosion weight loss was calculated.

The survey results are shown in Table 4.

From these results, the crevice corrosion weight loss was remarkably large when none of Ti, Zr and Nb was added (Comparative Steel No. 21), but at least one of Ti, Zr and Nb was added in an appropriate amount. It can be seen that the corrosion weight loss is significantly reduced in the cases (invention steel Nos. 1 to 12). This is especially true
It is more clear when the steel No. 4 of the present invention and the comparative steel No. 21, which have the same neutron absorption capacity, are compared. However, adding a large amount causes deterioration of hot rolling property (Comparative Steel No. 24,
No.25). Also, in Comparative Steel No. 22 with a low Cr content, Ti
However, the corrosion resistance cannot be improved even by adding.

When an appropriate amount of at least one of Mo, W and V is added, the crevice corrosion weight loss is further reduced and the corrosion resistance is further improved (inventive steels No. 16 to No. 20). Further, when Gd is contained, the invention steels No. 13 to No. 15 and the invention steel No. 4
As is clear from the comparison with, the hot rolling property can be improved.

[0062]

[Table 1 (1)]

[0063]

[Table 1 (2)]

[0064]

[Table 2 (1)]

[0065]

[Table 2 (2)]

[0066]

[Table 3 (1)]

[0067]

[Table 3 (2)]

[0068]

[Table 4 (1)]

[0069]

[Table 4 (2)]

[0070]

INDUSTRIAL APPLICABILITY The stainless steel of the present invention has a higher neutron absorption capacity than the conventional high B stainless steel, and has a corrosion resistance,
It is excellent in hot rolling property and is suitable as neutron shielding austenitic stainless steel used as a material for containers for transporting nuclear fuel, racks for storing spent nuclear fuel and the like.

[Brief description of drawings]

FIG. 1 is a diagram showing the shape of a crevice corrosion test piece.
(b) is a plan view of the corrosion test piece before assembly, and (c) is a side view of the crevice corrosion test piece after assembly.

Claims (12)

[Claims] 1. By weight%, C: 0.02% or less, Si: 0.5% or less, Mn: 2% or less, Ni: 10-22%, Cr: 18-26%, B:
3.0% or less, Gd: 0.05 to 1.0%, Mg: 0.1% or less, sol.
Al: A high corrosion resistant boron-containing stainless steel containing 0.5% or less and the balance being Fe and inevitable impurities. 2. In addition to the component according to claim 1, further
% By weight, Cd: 1% or less, Sm: 1% or less and Eu: 1%
A high corrosion resistant boron-containing stainless steel containing at least one of the following, with the balance being Fe and inevitable impurities. 3. In addition to the component according to claim 1, further
A high corrosion resistant boron-containing stainless steel containing 0.1 to 5% by weight of one or more of Mo, W and V alone or in total, and the balance being Fe and inevitable impurities. 4. In addition to the component according to claim 1, further
% By weight, Cd: 1% or less, Sm: 1% or less and Eu: 1%
One or more of the following, and one or more of Mo, W and V alone or in total of 0.1 to 5% are contained, and the balance is Fe.
And stainless steel containing high corrosion resistance boron, which is characterized by comprising unavoidable impurities. 5. By weight%, C: 0.02% or less, Si: 0.5% or less, Mn: 2% or less, Ni: 10-22%, Cr: 18-26%, B:
3.0% or less, one or more of Ti, Zr and Nb alone or in total 0.1 to 5%, Mg: 0.1% or less, sol.Al: 0.5%
A high corrosion resistant boron-containing stainless steel characterized by containing the following and the balance consisting of Fe and unavoidable impurities. 6. In addition to the component according to claim 5, further
% By weight, Cd: 1% or less, Sm: 1% or less and Eu: 1%
A high corrosion resistant boron-containing stainless steel containing at least one of the following, with the balance being Fe and inevitable impurities. 7. In addition to the component according to claim 5, further comprising:
A high corrosion resistant boron-containing stainless steel containing 0.1 to 5% by weight of one or more of Mo, W and V alone or in total, and the balance being Fe and inevitable impurities. 8. In addition to the component according to claim 5, further
% By weight, Cd: 1% or less, Sm: 1% or less and Eu: 1%
One or more of the following, and one or more of Mo, W and V alone or in total of 0.1 to 5% are contained, and the balance is Fe.
And stainless steel containing high corrosion resistance boron, which is characterized by comprising unavoidable impurities. 9. In addition to the components according to claim 5, further
A high corrosion resistant boron-containing stainless steel, characterized by containing Gd: 0.05 to 1.0% by weight and the balance Fe and unavoidable impurities. 10. In addition to the components according to claim 5, Gd: 0.05 to 1.0%, Cd: 1% or less, S, in weight%.
A highly corrosion resistant boron-containing stainless steel, characterized in that it contains at least one of m: 1% or less and Eu: 1% or less, and the balance is Fe and inevitable impurities. 11. In addition to the components according to claim 5, Gd: 0.05 to 1.0% by weight, and one or more of Mo, W and V alone or in total of 0.1 to 5%. A stainless steel containing high corrosion resistance boron containing, and, and the balance consisting of Fe and unavoidable impurities. 12. In addition to the components according to claim 5, Gd: 0.05 to 1.0% by weight, and one or more of Mo, W and V alone or in total of 0.1 to 5%. And Cd: 1
%, Sm: 1% or less and Eu: 1% or more of 1% or less, and the balance consisting of Fe and inevitable impurities, and a high corrosion resistant boron-containing stainless steel.