HIGH-Mn AUSTENITIC STAINLESS STEEL FOR HYDROGEN HAVING EXCELLENT WELDABILITY, WELDED JOINT USING SAME, DEVICE FOR HYDROGEN USING SAME, AND METHOD FOR PRODUCING WELDED JOINT

• US 20200131610A1
• Filed: 03/20/2018
• Published: 04/30/2020
• Est. Priority Date: 03/30/2017
• Status: Active Grant

• Current Assignee: Nippon Steel Stainless Steel Corporation (Nippon Steel Corporation)
• Original Assignee: Nippon Steel Stainless Steel Corporation (Nippon Steel Corporation)
• Inventors: MATSUMOTO, Kazuhisa, HATANO, Masaharu, NAKAMURA, Jun
• Granted Patent: US 11,225,705 B2
• Time in Patent Office: Days
• CPC Class Codes: B23K 2103/05 Stainless steel
• CPC Class Codes: B23K 26/32 taking account of the properties of the material involved
• CPC Class Codes: B23K 35/30 with the principal constituent melting at less than 1550 degrees C
• CPC Class Codes: B23K 9/23 taking account of the properties of the materials to be welded
• CPC Class Codes: C21D 6/00 Heat treatment of ferrous alloys
• CPC Class Codes: C21D 6/004 containing Cr and Ni
• CPC Class Codes: C21D 9/50 for welded joints
• CPC Class Codes: C22C 38/00 Ferrous alloys, e.g. steel alloys cast-iron alloys C22C37/00
• CPC Class Codes: C22C 38/001 containing N
• CPC Class Codes: C22C 38/002 containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
• CPC Class Codes: C22C 38/008 containing tin
• CPC Class Codes: C22C 38/02 containing silicon
• CPC Class Codes: C22C 38/04 containing manganese
• CPC Class Codes: C22C 38/06 containing aluminium
• CPC Class Codes: C22C 38/34 with more than 1.5% by weight of silicon
• CPC Class Codes: C22C 38/42 with copper
• CPC Class Codes: C22C 38/44 with molybdenum or tungsten
• CPC Class Codes: C22C 38/46 with vanadium
• CPC Class Codes: C22C 38/48 with niobium or tantalum
• CPC Class Codes: C22C 38/50 with titanium or zirconium
• CPC Class Codes: C22C 38/52 : with cobalt
• CPC Class Codes: C22C 38/58 : with more than 1.5% by weight of manganese
• CPC Class Codes: C22C 38/60 : containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur
• CPC Class Codes: Y02E 60/32 : Hydrogen storage

Abstract

This austenitic stainless steel contains, by mass %: C: 0.3% or less, Si: 0.1% to 1.5%, Mn: 5.5% to 20%, P: 0.050% or less, S: 0.005% or less, Cr: 10% to 20%, Ni: 4.0% to 12%, N: 0.40% or less, Cu: 4.0% or less, O: 0.02% or less, and either one or both of Ca: 0.01% or less and Al: 0.3% or less, with a remainder being Fe and inevitable impurities, and the following Formula (1) is satisfied.

[Ni]+[Cu]+12.93[C]+1.11[Mn]+0.72[Cr]+0.88[Mo]−0.27[Si]+7.55[N]≥29.3   Formula (1)

Claims

1-11. -11. (canceled)

12. A high-Mn austenitic stainless steel for hydrogen having excellent weldability, the steel comprising, by mass %:

C;

0.3% or less, Si;

0.1% to 1.5%, Mn;

5.5% to 20%, P;

0.050% or less, S;

0.005% or less, Cr;

10% to 20%, Ni;

4.0% to 12%, N;

0.40% or less, Cu;

4.0% or less, O;

0.02% or less, and either one or both of Ca;

0.01% or less and Al;

0.3% or less, and further comprising;

one or more selected from the group consisting of Sn, Zn, and Pb such that the amounts thereof satisfy the following Formula (2), with a remainder being Fe and inevitable impurities,

wherein the following Formula (1) is satisfied;

[Ni]+[Cu]+12.93[C]+1.11[Mn]+0.72[Cr]+0.88[Mo]−

0.27[Si]+7.55[N]≥

29.3 

 

Formula (1)

[Si], [Ni], [Cu], [C], [Mn], [Cr], [Mo], and [N] each represent an amount (mass %) of each element, and a value of an element which is not contained is set to 0,

1.2≥

29([S]+[P])+4[O]−

18[Ca]−

0.4[Al]−

0.02[Si]+5([Sn]+[Zn]+[Pb])≥

0.18 

 

Formula (2)

[S], [P], [O], [Ca], [Al], [Si], [Sn], [Zn], and [Pb] each represent an amount (mass %) of each element, and a value of an element which is not contained is set to 0.

13. The high-Mn austenitic stainless steel for hydrogen having excellent weldability according to claim 12, further comprising, by mass %:

Mo;

2.0% or less.

14. The high-Mn austenitic stainless steel for hydrogen having excellent weldability according to claim 12, further comprising:

one or more selected from the following groups;

first group;

by mass %, one or more of Ti;

1.0% or less, Nb;

1.0% or less, V;

1.0% or less, and W;

1.0% or less,

second group;

by mass %, Co;

1.0% or less, and

third group;

by mass %, Sb;

0.01% or less.

15. The high-Mn austenitic stainless steel for hydrogen having excellent weldability according to claim 12,

wherein the austenitic stainless steel is used in a high-pressure hydrogen gas and liquid hydrogen environment.

16. A welded joint consisting of:

the austenitic stainless steel according to claim 12,

wherein by mass %, [Mn];

8.0% to 25.0% and [Cu];

2.0% to 8.0% are contained as a chemical composition at grain boundaries in a weld.

17. A device for hydrogen comprising:

the austenitic stainless steel according to claim 12,

wherein the device for hydrogen is used in a high-pressure hydrogen gas and liquid hydrogen environment.

18. The device for hydrogen according to claim 17, which is any one of the group consisting of a tank body, a liner, a pipe, a valve, a steel sheet, and a heat exchanger.

19. A device for hydrogen comprising:

the welded joint according to claim 16,

wherein the device for hydrogen is used in a high-pressure hydrogen gas and liquid hydrogen environment.

20. The device for hydrogen according to claim 19, which is any one of the group consisting of a tank body, a liner, a pipe, a valve, a steel sheet, and a heat exchanger.

21. A method for producing a welded joint, the method comprising:

a step of welding the austenitic stainless steel according to claim 12; and

a step of performing a heat treatment at a temperature of 900°

C. to 980°

C. for 1 to 10 minutes,

wherein through the heat treatment, grain boundaries in which by mass %, [Mn];

8.0% to 25.0% and [Cu];

2.0% to 8.0% are contained as a chemical composition are obtained in a weld.

22. The high-Mn austenitic stainless steel for hydrogen having excellent weldability according to claim 13, further comprising:

one or more selected from the following groups;

first group;

by mass %, one or more of Ti;

1.0% or less, Nb;

1.0% or less, V;

1.0% or less, and W;

1.0% or less,

second group;

by mass %, Co;

1.0% or less, and

third group;

by mass %, Sb;

0.01% or less.

23. The high-Mn austenitic stainless steel for hydrogen having excellent weldability according to claim 13,

wherein the austenitic stainless steel is used in a high-pressure hydrogen gas and liquid hydrogen environment.

24. The high-Mn austenitic stainless steel for hydrogen having excellent weldability according to claim 14,

wherein the austenitic stainless steel is used in a high-pressure hydrogen gas and liquid hydrogen environment.

25. A welded joint consisting of:

the austenitic stainless steel according to claim 13,

wherein by mass %, [Mn];

8.0% to 25.0% and [Cu];

2.0% to 8.0% are contained as a chemical composition at grain boundaries in a weld.

26. A welded joint consisting of:

the austenitic stainless steel according to claim 14,

wherein by mass %, [Mn];

8.0% to 25.0% and [Cu];

2.0% to 8.0% are contained as a chemical composition at grain boundaries in a weld.

27. A welded joint consisting of:

the austenitic stainless steel according to claim 15,

wherein by mass %, [Mn];

8.0% to 25.0% and [Cu];

2.0% to 8.0% are contained as a chemical composition at grain boundaries in a weld.

28. A device for hydrogen comprising:

the austenitic stainless steel according to claim 13,

wherein the device for hydrogen is used in a high-pressure hydrogen gas and liquid hydrogen environment.

29. A device for hydrogen comprising:

the austenitic stainless steel according to claim 14,

wherein the device for hydrogen is used in a high-pressure hydrogen gas and liquid hydrogen environment.

30. A device for hydrogen comprising:

the austenitic stainless steel according to claim 15,

wherein the device for hydrogen is used in a high-pressure hydrogen gas and liquid hydrogen environment.

31. A welded joint comprising:

the austenitic stainless steel according to claim 12,

wherein by mass %, [Mn];

8.0% to 25.0% and [Cu];

2.0% to 8.0% are contained as a chemical composition at grain boundaries in a weld.