摘要:
A method of manufacturing a seamless steel pipe having excellent properties with high productivity in on-line processing, and an apparatus in which includes casting and heat treatment unit on-line. In the method the following steps (1) to (6) are successively performed. (1) A round billet is produced by continuous casting machine 1. (2) The billet is cooled to a temperature not higher than a Ar.sub.1 point, then heated and soaked in a furnace 3. (3) The billet is pierced by a piercer 5 at a strain rate of not higher than 200/sec and made into a hollow shell. (4) The hollow shell is elongated and finish rolled to make into a seamless steel pipe at an average strain rate of not lower than 0.01/sec and with a reduction ratio of not lower than 40%, and finishing the rolling at a temperature from 800.degree. C. to 1050.degree. C. (5) The seamless steel pipe is cooled to a temperature not higher than the Ar.sub.3 point at a cooling rate of not lower than 80.degree. C./min. (6) The cooled pipe is reheated to a temperature 850-1000.degree. C., held for 10 sec. to 30 min., then quenched and tempered.
摘要:
The manufacturing method of the present invention comprises steps (1) through (8) which are sequentially arranged, and the steps or equipment from the production of billets to end products are connected in the same single continuous manufacturing line:(1) a step of producing a round billet by continuous casting,(2) a step of cooling the billet to a temperature not higher than an A.sub.r1 transformation temperature,(3) a step of heating the billet to a temperature which allows piercing of the billet,(4) a step of piercing, at a strain rate of not higher than 200/sec, the billet to obtain a hollow shell,(5) a step to form a steel pipe by elongating and finish rolling the hollow shell using a continuous elongating mill and a finish rolling mill which are directly connected to each other, at a predetermined average strain rate, a predetermined reduction ratio, and at a predetermined finishing temperature,(6) a step of recrystallizing the steel pipe at a temperature of not lower than an Ar.sub.r3 transformation temperature,(7) a step of quenching the steel pipe from a temperature not lower than an A.sub.r3 transformation temperature, and(8) a step of tempering the steel pipe.
摘要:
A method of producing a tool steel comprises quenching a steel containing, by mass percent, C: 0.25 to 0.60%, Si: 0.10 to 1.20%, Mn: 0.20 to 1.50%, Ni: 0.50 to 2.00%, Cr: 1.00 to 4.20%, Mo: 0.30 to 2.00%, V: 0.10 to 1.00% and Al: 0.005 to 0.10%, in order to obtain a hardness H such that the hardness index defined below by the formula (1) becomes between 0.20 to 0.95; and then tempering the steel; K=(H−H2)/(H1−H2) (1) Where H1: Vickers hardness of the steel with 10 mm thickness after heating to a temperature of the Ac3 transformation point plus 50° C., and quenching into water; H2: Vickers hardness of the steel with 10 mm thickness after heating to the same temperature as defined above, and cooling to room temperature over 20 hours.
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:
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 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:
Disclosed is an electroluminescent element (10) which includes an anode layer (12), a cathode layer (14), a first low refractive index layer (13) that is formed between the anode layer (12) and the cathode layer (14), a recessed portion (16) that penetrates at least the anode layer (12) and the first low refractive index layer (13), a second low refractive index layer (19) that is formed on the bottom of the recessed portion (16), and a light emitting portion (17) that is formed on the second low refractive index layer (19). The electroluminescent element (10) is also characterized in that the refractive index of the first low refractive index layer (13) and the refractive index of the second low refractive index layer (19) are lower than the refractive index of the light emitting portion (17). The electroluminescent element (10) provides an electroluminescent element which has high light-emitting efficiency when the light emitted from the light emitting portion is taken out from the substrate side.
摘要:
There is provided a method for manufacturing a seamless steel pipe for line pipe, capable of improving the toughness of the seamless steel pipe for line pipe. A round billet having a chemical composition, by mass percent, of C: 0.02 to 0.15%, Si: at most 0.5%, and Mn: 0.5 to 2.5%, the balance being Fe and impurities, is heated. The heated round billet is piercing-rolled to produce a hollow shell. The hollow shell is elongated and rolled and sized to produce a seamless steel pipe. The seamless steel pipe is water cooled, and the water cooling is stopped when the temperature of the seamless steel pipe reaches at most 450° C. The water-cooled seamless steel pipe is quenched, and the quenched seamless steel pipe is tempered.
摘要:
The present invention provides an induction-hardened hollow driving shaft that comprises, as a raw material, a steel pipe that contains, by mass %, 0.30 to 0.47% C, 0.5% or less Si, 0.3 to 2.0% Mn, 0.018% or less P, 0.015% or less S, 0.15 to 1.0% Cr, 0.001 to 0.05% Al, 0.005 to 0.05% Ti, 0.004% or less Ca, 0.01% or less N, 0.0005 to 0.005% B and 0.0050% or less O (oxygen) and the balance Fe and impurities and of which Beff defined by an equation (a) or (b) below is 0.0001 or more, wherein a prior austenite grain size number (JIS G0551) after the hardening is 9 or more. Here, in the case of Neff=N−14×Ti/47.9≧0, Beff=B−10.8×(N−14×Ti/47.9)/14 . . . (a), and, in other cases, Beff=B . . . (b). According to the present invention, a hollow driving shaft that is simultaneously provided with excellent cold workability, hardenability, toughness and torsional fatigue strength and can exert stable fatigue lifetime can be obtained and can be widely utilized.
摘要:
A seamless steel pipe for line pipe having a high strength and good toughness and corrosion resistance even though having a thick wall has a chemical composition comprising, in mass percent, C: 0.02-0.08%, Si: at most 0.5%, Mn: 1.5-3.0%, Al: 0.001-0.10%, Mo: greater than 0.4% to 1.2%, N: 0.002-0.015%, Ca: 0.0002-0.007%, and a remainder of Fe and impurities, wherein the contents of the impurities are at most 0.03% for P, at most 0.005% for S, at most 0.005% for O and less than 0.0005% for B and wherein the value of Pcm calculated by the following Equation (1) is at least 0.185 and at most 0.250. The steel pipe has a microstructure which primarily comprises bainite and which has a length of cementite of at most 20 micrometers: Pcm=[C]+[Si]/30+([Mn]+[Cr]+[Cu])/20+[Mo]/15+[V]/10+5[B] (1) wherein [C], [Si], [Mn], [Cr], [Cu], [Mo], [V] and [B] are numbers respectively indicating the content in mass percent of C, Si, Mn, Cr, Cu, Mo, V and B.