High strength austenitic stainless steel having excellent resistance to hydrogen embrittlement, method for manufacturing the same, and hydrogen equipment used for high-pressure hydrogen gas and liquid hydrogen environment

Patent metadata

Field	Value
Publication number	US-11149324-B2
Application number	US-201615078562-A
Country	US
Kind code	B2
Filing date	Mar 23, 2016
Priority date	Mar 26, 2015
Publication date	Oct 19, 2021
Grant date	Oct 19, 2021

Abstract

This high strength austenitic stainless steel having excellent resistance to hydrogen embrittlement includes, in terms of mass %, C: 0.2% or less, Si: 0.2% to 1.5%, Mn: 0.5% to 2.5%, P: 0.06% or less, S: 0.008% or less, Ni: 10.0% to 20.0%, Cr: 16.0% to 25.0%, Mo: 3.5% or less, Cu: 3.5% or less, N: 0.01% to 0.50%; and O: 0.015% or less, with the balance being Fe and unavoidable impurities, in which an average size of precipitates is 100 nm or less and an amount of the precipitates is 0.001% to 1.0% in terms of mass %.

First claim

The invention claimed is:

1. An austenitic stainless steel having resistance to hydrogen embrittlement comprising, in terms of mass %:
C: 0.2% or less;
Si: 0.2% to 1.5%;
Mn: 0.5% to 2.5%;
P: 0.042% or less;
S: 0.008% or less;
Ni: 10.0% to 20.0%;
Cr: 16.0% to 19.1%;
Mo: 3.5% or less;
Cu: 1.52% or less;
N: 0.01% to 0.50%; and
O: 0.015% or less,
with a balance being Fe and unavoidable impurities,
wherein an average size of precipitates is 100 nm or less and an amount of the precipitates is 0.001% to 1.0% in terms of mass %.

2. The austenitic stainless steel having resistance to hydrogen embrittlement according to claim 1 , further comprising one or more selected from the group consisting of, in terms of mass %,
Al: 0.3% or less,
Mg: 0.01% or less,
Ca: 0.01% or less,
REM: 0.10% or less, and
B: 0.008% or less.

3. The austenitic stainless steel having resistance to hydrogen embrittlement according to claim 1 , further comprising one or more selected from the group consisting of, in terms of mass %,
Ti: 0.5% or less,
Nb: 0.5% or less, and
V: 0.5% or less.

4. The austenitic stainless steel having resistance to hydrogen embrittlement according to claim 1 , which is used for a high-pressure hydrogen gas and liquid hydrogen environment.

5. A method for manufacturing the austenitic stainless steel having resistance to hydrogen embrittlement according to claim 1 , the method comprising:
subjecting a semi-finished product having a component composition comprising, in terms of mass %:
C: 0.2% or less;
Si: 0.2% to 1.5%;
Mn: 0.5% to 2.5%;
P: 0.042% or less;
S: 0.008% or less;
Ni: 10.0% to 20.0%;
Cr: 16.0% to 19.1%;
Mo: 3.5% or less;
Cu: 1.52% or less;
N: 0.01% to 0.50%; and
O: 0.015% or less,
with a balance being Fe and unavoidable impurities, to hot working;
performing a final heat treatment at a temperature of 1000° C. to 1200° C.; and
performing cooling after the final heat treatment,
wherein, in the cooling, an average cooling rate until a temperature reaches 750° C. is controlled to be less than 2.0° C./s.

6. The austenitic stainless steel having resistance to hydrogen embrittlement according to claim 2 , further comprising one or more selected from the group consisting of, in terms of mass %,
Ti: 0.5% or less,
Nb: 0.5% or less, and
V: 0.5% or less.

7. The austenitic stainless steel having resistance to hydrogen embrittlement according to claim 2 , which is used for a high-pressure hydrogen gas and liquid hydrogen environment.

8. The austenitic stainless steel having resistance to hydrogen embrittlement according to claim 3 , which is used for a high-pressure hydrogen gas and liquid hydrogen environment.

9. A method for manufacturing the austenitic stainless steel having resistance to hydrogen embrittlement according to claim 2 , the method comprising:
subjecting a semi-finished product having a component composition comprising, in terms of mass %:
C: 0.2% or less;
Si: 0.2% to 1.5%;
Mn: 0.5% to 2.5%;
P: 0.042% or less;
S: 0.008% or less;
Ni: 10.0% to 20.0%;
Cr: 16.0% to 19.1%;
Mo: 3.5% or less;
Cu: 1.52% or less;
N: 0.01% to 0.50%;
O: 0.015% or less; and
one or more selected from the group consisting of, in terms of mass %,
Al: 0.3% or less,
Mg: 0.01% or less,
Ca: 0.01% or less,
REM: 0.10% or less, and
B: 0.008% or less;
with a balance being Fe and unavoidable impurities, to hot working;
performing a final heat treatment at a temperature of 1000° C. to 1200° C.; and
performing cooling after the final heat treatment,
wherein, in the cooling, an average cooling rate until a temperature reaches 750° C. is controlled to be less than 2.0° C./s.

10. A method for manufacturing the austenitic stainless steel having resistance to hydrogen embrittlement according to claim 3 , the method comprising:
subjecting a semi-finished product having a component composition comprising, in terms of mass %:
C: 0.2% or less;
Si: 0.2% to 1.5%;
Mn: 0.5% to 2.5%;
P: 0.042% or less;
S: 0.008% or less;
Ni: 10.0% to 20.0%;
Cr: 16.0% to 19.1%;
Mo: 3.5% or less;
Cu: 1.52% or less;
N: 0.01% to 0.50%;
O: 0.015% or less; and
one or more selected from the group consisting of, in terms of mass %,
Ti: 0.5% or less,
Nb: 0.5% or less, and
V: 0.5% or less;
with a balance being Fe and unavoidable impurities, to hot working;
performing a final heat treatment at a temperature of 1000° C. to 1200° C.; and
performing cooling after the final heat treatment,
wherein, in the cooling, an average cooling rate until a temperature reaches 750° C. is controlled to be less than 2.0° C./s.

Assignees

• Nippon Steel & Sumikin Sst
• Nippon Steel Stainless Steel Corp

Inventors

• Matsumoto Kazuhisa
• Hatano Masaharu

Classifications

• C21D8/00

  Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment (hardening articles or materials formed by forging or rolling with no further heating beyond that required for the formation C21D1/02) · CPC title

• F17C1/14

  constructed of aluminium; constructed of non-magnetic steel · CPC title

• C22C38/54

  with boron · CPC title

• C22C38/46

  with vanadium · CPC title

• F17C2203/0648

  Alloys or compositions of metals · CPC title