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
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 %.
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.