摘要:
The medium carbon, microalloyed forging steel for machine structural use has a small deformation upon fracture in a hot-rolled, hot-forged, or any other hot-worked state, has an inexpensive ferrite-pearlitic microstructure and consists of C: 0.3 to 0.6 wt %, Si: 0.1 to 2.0 wt %, Mn: 0.1 wt % or more and less than 0.4 wt %, P: 0.01 to 0.1 wt %, S: 0.01 to 0.2 wt %, V: more than 0.15 wt % and up to 0.4 wt %, and the balance: Fe and unavoidable impurities, in which the unavoidable impurities include less than 0.005 wt % N. The microalloyed forging steel for machine structural use may further contain Al: 0.005 to 0.05 wt %, one or both of Ti: 0.005 to 0.05 wt % and Nb: 0.05 to 0.2 wt %, and/or one or both of Cr: 0.1 to 0.5 wt % and Mo: 0.1 to 0.5 wt %.
摘要:
A method of heat-treating a steel member including carburizing a steel member in a carburizing gas under a reduced pressure. The steel member is then cooled in a cooling gas having a pressure lower than atmospheric pressure. A desired portion of the cooled steel member is then heated using high-density energy. The steel member is then quenched.
摘要:
A process for preparing silver halide emulsions having high sensitivity and contrast by adding water-soluble iridium compounds during precipitation or physical ripening and adding water-soluble iodide compounds and sulfer sensitizers during chemical ripening.
摘要:
A carburizing and hardening method enhances strength while sufficiently reducing hardening strain, without increasing the production cost, and a carburized and hardened member produced thereby. The raw material is an alloy steel which contains Fe as a main component, 0.10 to 0.50 wt. % C and 0.50 to 1.50 wt. % Si and having a hardenability J, based on an end quenching test, in a range of 35 to 50 (at 12.5 mm). After the raw material is formed into the desired shape, a carburized layer is formed by carburizing in an oxidation inhibiting atmosphere. After the carburizing, quenching is performed with cooling, uninterrupted by temperature rise, from a pearlite transformation point (A1 point) to a martensite transformation start point (Ms point), and with a severity of quenching H in a range of 0.01 to 0.08 (cm−1).
摘要翻译:渗碳硬化方法提高强度,同时充分降低硬化应变,而不增加生产成本,并且由此生产的渗碳硬化构件。 原料是含有Fe作为主要成分的合金钢,0.10〜0.50重量% %C和0.50〜1.50wt。 %Si,并且基于终止淬火试验具有淬透性J,在35〜50(12.5mm)的范围内。 在原料形成所需形状之后,通过在氧化抑制气氛中渗碳形成渗碳层。 渗碳后,从珠光体相变点(A1点)到马氏体相变开始点(Ms点)的冷却不间断地进行淬火淬火,淬火强度H在0.01〜0.08的范围内( cm -1)。
摘要:
A method of heat-treating a steel member including carburizing a steel member in a carburizing gas under a reduced pressure. The steel member is then cooled in a cooling gas having a pressure lower than atmospheric pressure. A desired portion of the cooled steel member is then heated using high-density energy. The steel member is then quenched.
摘要:
A high strength bold superior in delayed fracture resistant property has a bolt tensile strength of 1200 N/mm2. A high strength bolt comprised of a head portion and shaft portion formed by a steel material, wherein the relation between a bolt tensile strength TS (N/mm2) and tempering temperature T (° C.) satisfies the following expression (1), the relation between the bolt tensile strength TS (N/mm2) and the carbon equivalent Ceq (%) calculated from the chemical composition of the steel material used for the high strength bolt satisfies the following expression (2), and the tensile strength of the bolt is refined to a range of 1200 N/mm2 to 1600 N/mm2 by quenching and tempering: TS≦1.1T+850 (1) TS≦550Ceq+1000 (2) where, C eq = C + ( Mn / 6 ) + ( Si / 24 ) + ( Ni / 40 ) + ( Cr / 5 ) + ( Mo / 4 ) + ( V / 14 ) .
摘要:
A steel component formed by carburizing and then induction-hardening of a steel consisting essentially of, by mass, C: minimum 0.08% and less than 0.3%; Si: maximum 2.0%; Mn: from 0.2% to 3.0%; P: maximum 0.03%; S: from 0.005% to 0.05%; Ni: maximum 1.5%; Cr: maximum 3.0%; Mo: maximum 1.0%; O: maximum 0.0025%; and N: from 0.005% to 0.03%; and further including either or both of, by mass, Al: from 0.005% to 0.05%, and Ti: from 0.005% to 0.05%; and still further including either or both of, by mass, V: maximum 0.3%, and Nb: maximum 0.3%; and a balance including Fe and unavoidable impurities. The hardness of the surface layer is at least 55 HRC and the hardness of the core portion is from 20 to 50 HRC. The core portion does not include a martensite structure.
摘要:
A steel component formed by carburizing and then induction-hardening of a steel consisting essentially of, by mass, C: minimum 0.08% and less than 0.3%; Si: maximum 2.0%; Mn: from 0.2% to 3.0%; P: maximum 0.03%; S: from 0.005% to 0.05%; Ni: maximum 1.5%; Cr: maximum 3.0%; Mo: maximum 1.0%; O: maximum 0.0025%; and N: from 0.005% to 0.03%; and further including either or both of, by mass, Al: from 0.005% to 0.05%, and Ti: from 0.005% to 0.05%; and still further including either or both of, by mass, V: maximum 0.3%, and Nb: maximum 0.3%; and a balance including Fe and unavoidable impurities. The hardness of the surface layer is at least 55 HRC and the hardness of the core portion is from 20 to 50 HRC. The core portion does not include a martensite structure.
摘要:
This invention provides a steel for cold forging, excellent in surface layer hardness and softening properties by annealing, which contains, in terms of wt %, C: 0.1 to 1.0%, Si: 0.1 to 2.0%, Mn: 0.01 to 1.50%, P: not greater than 0.100%, S: not greater than 0.500%, sol. N: not greater than 0.005% and the balance consisting of Fe and unavoidable impurities, wherein a pearlite ratio in the steel structure is not greater than 120×(C %) % and the outermost surface layer hardness is at least 450×(C %)+90 in terms of the Vickers hardness HV, and a production method thereof. The invention provides also a steel for cold forging, which has a structure wherein a ratio of graphite amount to the carbon content in the steel exceeds 20%, a mean grain diameter of graphite is not greater than 10×(C %)⅓ &mgr;m and a maximum grain diameter is not greater than 20 &mgr;m.