High-strength austenitic stainless steel for high-pressure hydrogen gas

Patent metadata

Field	Value
Publication number	US-10266909-B2
Application number	US-201214007992-A
Country	US
Kind code	B2
Filing date	Mar 19, 2012
Priority date	Mar 28, 2011
Publication date	Apr 23, 2019
Grant date	Apr 23, 2019

Abstract

There is provided an austenitic stainless steel for high-pressure hydrogen gas consisting, by mass percent, of C: 0.10% or less, Si: 1.0% or less, Mn: 3% or more to less than 7%, Cr: 15 to 30%, Ni: 10% or more to less than 17%, Al: 0.10% or less, N: 0.10 to 0.50%, and at least one kind of V: 0.01 to 1.0% and Nb: 0.01 to 0.50%, the balance being Fe and impurities, wherein in the impurities, the P content is 0.050% or less and the S content is 0.050% or less, the tensile strength is 800 MPa or higher, the grain size number (ASTM E112) is No. 8 or higher, and alloy carbo-nitrides having a maximum diameter of 50 to 1000 nm are contained in the number of 0.4/μm 2 or larger in cross section observation.

First claim

The invention claimed is:

1. An austenitic stainless steel for hydrogen gas comprising: by mass percent, C: 0.10% or less, Si: 1.0% or less, Mn: 3% or more to less than 7%, Cr: 15 to 24%, Ni: 10% to 15%, Al: 0.001 to 0.10%, N: 0.10 to 0.50%, and V: 0.01 to 1.0%, the balance being Fe and impurities,
wherein in the impurities, the P content is 0.050% or less and the S content is 0.050% or less, the tensile strength is 800 MPa or higher, a relative rupture elongation is 80% or more, the grain size number in accordance with ASTM E112 is No. 8 or higher, and alloy carbo-nitrides having a maximum diameter of 50 to 1000 nm are contained in the number of 0.4/μm 2 or larger in cross section observation.

2. The austenitic stainless steel for hydrogen gas according to claim 1
wherein the austenitic stainless steel is subjected to solid solution heat treatment at a temperature of 1000 to 1200° C., next being subjected to cold rolling in which the reduction of area is 20% or more, and thereafter is again subjected to heat treatment in the temperature range of 900° C. or higher and lower than the solution treatment temperature.

3. An austenitic stainless steel for hydrogen gas comprising: by mass percent, C: 0.10% or less, Si: 1.0% or less, Mn: 3% or more to less than 7%, Cr: 15 to 24%, Ni: 10% to 15%, Al: 0.001 to 0.10%, N: 0.10 to 0.50%, and V: 0.010 to 1.0%, further containing Nb: 0.01 to 0.50%, and/or containing at least one element selected from element groups of a first group to a fourth group described below, the balance being Fe and impurities,
wherein in the impurities, the P content is 0.050% or less and the S content is 0.050% or less, the tensile strength is 800 MPa or higher, a relative rupture elongation is 80% or more, the grain size number in accordance with ASTM E112 is No. 8 or higher, and alloy carbo-nitrides having a maximum diameter of 50 to 1000 nm are contained in the number of 0.4/μm 2 or larger in cross section observation:

first group elements: Mo: 0.3 to 3.0% and W: 0.3 to 6.0%;
second group elements: Ti: 0.001 to 0.5%, Zr: 0.001 to 0.5%, Hf: 0.001 to 0.3%, and Ta: 0.001 to 0.6%;
third group elements: B: 0.0001 to 0.020%, Cu: 0.3 to 5.0%, and Co: 0.3 to 10.0%; and
fourth group elements: Mg: 0.0001 to 0.0050%, Ca: 0.0001 to 0.0050%, La: 0.0001 to 0.20%, Ce: 0.0001 to 0.20%, Y: 0.0001 to 0.40%, Sm: 0.0001 to 0.40%, Pr: 0.0001 to 0.40%, and Nd: 0.0001 to 0.50%.

4. The austenitic stainless steel for hydrogen gas according to claim 2 , wherein the austenitic stainless steel is subjected to solid solution heat treatment at a temperature of 1000 to 1200° C., next being subjected to cold rolling in which the reduction of area is 20% or more, and thereafter is again subjected to heat treatment in the temperature range of 900° C. or higher and lower than the solution treatment temperature.

Assignees

• Omura Tomohiko
• Nakamura Jun
• Okada Hirokazu
• Semba Hiroyuki
• Tomio Yusaku
• Hirata Hiroyuki
• Igarashi Masaaki
• Ogawa Kazuhiro
• Terunuma Masaaki
• Nippon Steel & Sumitomo Metal Corp

Inventors

• Omura Tomohiko
• Nakamura Jun
• Okada Hirokazu
• Semba Hiroyuki
• Tomio Yusaku
• Hirata Hiroyuki
• Igarashi Masaaki
• Ogawa Kazuhiro
• Terunuma Masaaki

Classifications

• C22C38/001

  containing N · CPC title

• C21D9/46 Primary

  for sheet metals · CPC title

• C22C38/44

  with molybdenum or tungsten · CPC title

• C21D8/0247

  characterised by the heat treatment · CPC title

• F16L9/02

  of metal (F16L9/16 - F16L9/22 take precedence) · CPC title