摘要:
A high-strength stainless steel for oil well having corrosion resistance excellent in a high-temperature environment, having excellent SSC resistance at normal temperature, and having better workability than 13% Cr steels has a chemical composition containing, by mass percent, C: at most 0.05%, Si: at most 1.0%, Mn: at most 0.3%, P: at most 0.05%, S: less than 0.002%, Cr: over 16% and at most 18%, Mo: 1.5 to 3.0%, Cu: 1.0 to 3.5%, Ni: 3.5 to 6.5%, Al: 0.001 to 0.1%, N: at most 0.025%, and O: at most 0.01%, the balance being Fe and impurities, a microstructure containing a martensite phase, 10 to 48.5%, by volume ratio, of a ferrite phase and at most 10%, by volume ratio, of a retained austenite phase, yield strength of at least 758 MPa and uniform elongation of at least 10%.
摘要:
The chemical composition of a stainless steel in accordance with the present invention consists of C: not more than 0.05%, Si: not more than 0.5%, Mn: 0.01 to 0.5%, P: not more than 0.04%, S: not more than 0.01%, Cr: more than 16.0 and not more than 18.0%, Ni: more than 4.0 and not more than 5.6%, Mo: 1.6 to 4.0%, Cu: 1.5 to 3.0%, Al: 0.001 to 0.10%, and N: not more than 0.050%, the balance being Fe and impurities, and satisfies Formulas (1) and (2). Also, the micro-structure thereof contains a martensitic phase and a ferritic phase having a volume ratio of 10 to 40%, and the ferritic phase distribution ratio is higher than 85%. Cr+Cu+Ni+Mo≧25.5 (1) −8≦30(C+N)+0.5Mn+Ni+Cu/2+8.2−1.1(Cr+Mo)≦−4 (2)
摘要翻译:根据本发明的不锈钢的化学组成由C:不大于0.05%,Si:不大于0.5%,Mn:0.01至0.5%,P:不大于0.04%,S:不大于 0.01%以上,Cr:16.0以上18.0%以下,Ni:4.0以上5.6%以下,Mo:1.6〜4.0%,Cu:1.5〜3.0%,Al:0.001〜0.10% N:不大于0.050%,余量为Fe和杂质,并满足式(1)和(2)。 此外,其微结构含有马氏体相和体积比为10〜40%的铁素体相,铁素体相分布比高于85%。 Cr + Cu + Ni +Mo≥25.5(1)-8≦̸ 30(C + N)+ 0.5Mn + Ni + Cu / 2 + 8.2-1.1(Cr + Mo)≦̸ -4(2)
摘要:
A high-strength stainless steel for oil well having corrosion resistance excellent in a high-temperature environment, having excellent SSC resistance at normal temperature, and having better workability than 13% Cr steels has a chemical composition containing, by mass percent, C: at most 0.05%, Si: at most 1.0%, Mn: at most 0.3%, P: at most 0.05%, S: less than 0.002%, Cr: over 16% and at most 18%, Mo: 1.5 to 3.0%, Cu: 1.0 to 3.5%, Ni: 3.5 to 6.5%, Al: 0.001 to 0.1%, N: at most 0.025%, and O: at most 0.01%, the balance being Fe and impurities, a microstructure containing a martensite phase, 10 to 48.5%, by volume ratio, of a ferrite phase and at most 10%, by volume ratio, of a retained austenite phase, yield strength of at least 758 MPa and uniform elongation of at least 10%.
摘要:
A high strength Cr—Ni alloy material excellent in hot workability and stress corrosion cracking resistance, and seamless pipe for oil well application which consists of, by mass percent, C: 0.05% or less, Si: 0.05 to 1.0%, Mn: 0.01% or more and less than 3.0%, P: 0.05% or less, S: 0.005% or less, Cu: 0.01 to 4%, Ni: 25% or more and less than 35%, Cr: 20 to 30%, Mo: 0.01% or more and less than 4.0%, N: 0.10 to 0.30%, Al: 0.03 to 0.30%, O (oxygen): 0.01% or less, and REM (rare earth metal): 0.01 to 0.20% with the balance being Fe and impurities, and also satisfies the conditions in the following formula (1). N×P/REM≦0.40 formula (1) where P, N, and REM in the formula (1) respectively denote the contents (mass %) of P, N, and REM. The high strength Cr—Ni alloy material may further contain one or more types of W, Ti, Nb, Zr, V, Ca, and Mg, instead of part of Fe.
摘要:
[Object] To provide a high strength Cr—Ni alloy material excellent in hot workability and stress corrosion cracking resistance, and seamless pipe for oil well.[Solution] A high strength Cr—Ni alloy material which consists of, by mass percent, C: 0.05% or less, Si: 0.05 to 1.0%, Mn: 0.01% or more and less than 3.0%, P: 0.05% or less, S: 0.005% or less, Cu: 0.01 to 4%, Ni: 25% or more and less than 35%, Cr: 20 to 30%, Mo: 0.01% or more and less than 4.0%, N: 0.10 to 0.30%, Al: 0.03 to 0.30%, O (oxygen): 0.01% or less, and REM (rare earth metal): 0.01 to 0.20%, with the balance being Fe and impurities, and also satisfies the conditions in the following formula (1). N×P/REM≦0.40 formula (1) where P, N, and REM in the formula (1) respectively denote the contents (mass %) of P, N, and REM. The high strength Cr—Ni alloy material may further contain one or more types of W, Ti, Nb, Zr, V, Ca, and Mg, instead of part of Fe.