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 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 problem to be solved is the provision of a high-strength stainless steel pipe having a sufficient corrosion resistance in a high-temperature carbonic acid gas environment and having an excellent sulfide stress cracking resistance at normal temperature. A high-strength stainless steel pipe consist of, by mass %, C: 0.05% or less, Si: 1.0% or less, P: 0.05% or less, S: less than 0.002%, Cr: more than 16% and 18% or less, Mo: more than 2% and 3% or less, Cu: 1% to 3.5%, Ni: 3% or more and less than 5%, Al: 0.001% to 0.1% and O: 0.01% or less, Mn: 1% or less and N: 0.05% or less, and Mn and N in the above ranges satisfy formula (1), and the balance being Fe and impurities; and the metal micro-structure of the stainless steel pipe mainly includes a martensitic phase and comprises 10 to 40% of a ferritic phase by volume fraction and 10% or less of a retained γ-phase by volume fraction. [Mn]×([N]−0.0045)≦0.001 (1) wherein the symbols of elements in formula (1) respectively represent the contents (unit: mass %) of the elements in the steel.
摘要:
A stainless steel for an oil country tubular good according to the invention includes, in percent by mass, 0.001% to 0.05% C, 0.05% to 1% Si, at most 2% Mn, at most 0.03% P, less than 0.002% S, 16% to 18% Cr, 3.5% to 7% Ni, more than 2% and at most 4% Mo, 1.5% to 4% Cu, 0.001% to 0.3% rare earth metal, 0.001% to 0.1% sol. Al, 0.0001% to 0.01% Ca, at most 0.05% O, and at most 0.05% N, and the balance consists of Fe and impurities. The stainless steel according to the invention includes REM and therefore has high SCC resistance in a high temperature chloride aqueous solution environment.
摘要:
An oil country tubular good for expansion according to the invention is expanded in a well. The oil country tubular good for expansion according to the invention is formed of duplex stainless steel having a composition containing, in percentage by mass, 0.005% to 0.03% C, 0.1% to 1.0% Si, 0.2% to 2.0% Mn, at most 0.04% P, at most 0.015% S, 18.0% to 27.0% Cr, 4.0% to 9.0% Ni, at most 0.040% Al, and 0.05% to 0.40% N, and the balance consisting of Fe and impurities, a structure including an austenite ratio in the range from 40% to 90%. The oil country tubular good for expansion according to the invention has a yield strength from 256 MPa to 655 MPa, and a uniform elongation more than 20%. Therefore, the oil country tubular good for expansion according to the invention has a high pipe expansion characteristic.
摘要:
A method for producing a high-strength Cr—Ni alloy seamless pipe comprising preparing an alloy billet with a chemical composition consisting, by mass %, of C: 0.05% or less, Si: 1.0% or less, Mn: less than 3.0%, P: 0.005% or less, S: 0.005% or less, Cu: 0.01 to 4.0%, 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, REM (rare earth metal): 0.01 to 0.20%, and the balance being Fe and impurities, and satisfying the formula N×P/REM≦0.10, wherein P, N and REM represent the contents (mass %) of P, N and REM, respectively. The pipe is hot worked using cross roll piercing, solution heat treated, and cold worked. The pipe is excellent in hot workability, stress corrosion cracking and does not laminate during cross piercing.
摘要:
A martensitic stainless steel comprising C: 0.01-0.10%, Si: 0.05-1.0%, Mn: 0.05-1.5%, P: not more than 0.03%, S: not more than 0.01%, Cr: 9-15%, Ni: 0.1-4.5%, Al: not more than 0.05% and N: not more than 0.1% in mass %, and further comprising at least one of Cu: 0.05-5% and Mo: 0.05-5%, the residual being Fe and impurities, is provided, wherein the contents of Cu and Mo satisfy the following formula (a) or (b), 0.2%≦Mo+Cu/4≦5% (a) 0.55%≦Mo+Cu/4≦5% (b) and wherein the hardness is 30-45 in HRC and the carbide amount in grain boundaries of the prior austenite is not more than 0.5 volume %. The marensitic stainless steel has excellent properties regarding the sulfide stress cracking resistance, the resistance to corrosive wear and the localized corrosion.
摘要翻译:一种马氏体不锈钢,其包含C:0.01〜0.10%,Si:0.05〜1.0%,Mn:0.05〜1.5%,P:0.03%以下,S:0.01%以下,Cr:9〜15%,Ni :0.1-4.5%,Al:0.05%以下,N:0.1质量%以下,进一步含有Cu:0.05〜5%和Mo:0.05〜5%中的至少一种,残留物为Fe 提供Cu和Mo的含量满足下式(a)或(b):0.2%< NlE; Mo + Cu / 4≦̸ 5%(a)0.55%≦̸ Mo + Cu / 4& 5%(b),硬度在HRC中为30-45,前奥氏体的晶界中的碳化物量不大于0.5体积%。 锰矿不锈钢具有耐硫化物应力开裂性,耐腐蚀性和局部腐蚀性等优异性能。
摘要:
A martensitic stainless steel having a resistance to sulfide stress corrosion cracking superior to Super 13 Cr steel and having a strength and corrosion resistance comparable to dual phase stainless steels has a chemical composition consisting essentially of, in mass %, C: 0.001-0.1%, Si: 0.05-1.0%, Mn: 0.05-2.0%, P: at most 0.025%, S: at most 0.010%, Cr: 11-18%, Ni: 1.5-10%, sol. Al: 0.001-0.1%, N: at most 0.1%, O: at most 0.01%, Cu: 0-5%, solid solution Mo: 3.5-7%, the composition satisfying the following Equation (1), optionally at least one element selected from at least one of the following Groups A-C, and a remainder of Fe and impurities and undissolved Mo, if undissolved Mo is present. Ni-bal.=30(C+N)+0.5(Mn+Cu)+Ni+8.2−1.1(Cr+Mo+1.5Si)≧−4.5 Equation (1) Group A—W: 0.2-5% Group B—V: 0.001-0.50%, Nb: 0.001-0.50%, Ti: 0.001-0.50%, and Zr: 0.001-0.50% Group C—Ca: 0.0005-0.05%, Mg: 0.0005-0.05%, REM: 0.0005-0.05%, and B: 0.0001-0.01%
摘要:
A martensitic stainless steel oil country tubular good contains, by mass, 0.005% to 0.1% C, 0.05% to 1% Si, 1.5% to 5% Mn, at most 0.05% P, at most 0.01% S, 9% to 13% Cr, at most 0.5% Ni, at most 2% Mo, at most 2% Cu, 0.001% to 0.1% Al, and 0.001% to 0.1% N, with the balance being Fe and impurities, and the pipe has a Cr-depleted region under the surface. The martensitic stainless steel oil country tubular good according to the present invention does not have a passive film on the surface and corrodes wholly at low speed. In addition, the Ni content is reduced, which allows uneven corrosion to be prevented. Therefore, SCC can be prevented from being generated in spite of the presence of a Cr-depleted region.