大功率机车齿轮钢（16R2Ni2A）性能的研究

简述了１６Ｃｒ２Ｎｉ２Ａ大功率机车齿轮钢的成份设计思想，研究了该钢的常规力学性能和特殊性能，建立ＴＴＴ衅和ＣＣＴ图，分析了钢中酸溶铝含量与奥氏晶粒度之间的关系，测定了奥氏体晶粒粗化温度和末端淬透性曲线。通过产品装车运行效果的全面调研，得出１６Ｃｒ２Ｎｉ２Ａ能满足大功率机车齿轮用钢的技术要求。     

高强度齿轮钢的开发

本文根据外刊资料，综述阐述了汽车用的高速高强度齿轮钢的开发情况。从齿轮的特性。齿轮的破坏机理出发，探讨了合金设计和新钢种的开发状况。重点阐述了高强度齿轮钢，特别详细的介绍了高弯曲疲劳强度齿轮钢，耐点蚀齿轮钢和０．１８Ｃ－０．７Ｍｎ－１．０Ｃｒ－０．４Ｍｏ高强度齿轮钢的试验研究结果，最后还简要的介绍了喷丸技术在提高齿轮钢强度上的应用情况。本文可供开发新型的高速高强度汽车齿轮用钢参考。     

我国中重型载货汽车用齿轮钢品种发展概况

简要介绍我国中、重型载货汽车用齿轮钢的品种及其发展概况，并提出莱钢齿轮钢品种开发建议。     

转炉试制22MnTiBRE齿轮钢

介绍了用大型转炉生产２２ＭｎＴｉＢＲＥ钢的工艺及其产品性能，通过出钢前向钢包内加入２００ｋｇ／炉的钙基脱氧剂，以及喂铝线，喂加包有Ｃａ，Ｂａ，ＲＥ，Ｓｉ，Ｃ，Ｆ的复合包芯线来净化钢液。并采用浇注时吊挂稀土棒和光亮剂，解决了大型转炉生产的钢液氧含量高，钢液分难以控制，大钢锭成分偏析大和普钢厂清理能力弱，钢材顶锻性能易保证的问题，保证了齿轮钢的淬透性带宽度，晶粒度及清洁度。表明了用转炉加精炼工艺可以生     

浅析齿轮钢及热处理工艺对汽车用齿轮性能的影响

齿轮是汽车上关键的传动部件,决定着汽车的安全性和舒适性.汽车齿轮的生产工艺复杂,影响其质量的因素较多,本文综述了钢材、热处理工艺两方面对汽车齿轮质量的影响.     

圆环链用钢20Mn2的研制

介绍了圆环链用钢20Mn2钢中主要元素对钢材性能的影响，总结了安阳钢铁集团有限责任公司生产20Mn2钢的工艺。     

奔驰载重汽车用Mo-Cr系列齿轮钢的研制

试制的奔驰载重汽车用Mo-Cr系列齿轮钢的化学成分、清洁度、淬透性已达到DBL4027要求.     

高端淬透性齿轮钢27MnCr5JV的研制

设计了用于汽车的高端淬透性齿轮钢及其生产工艺,通过对化学成分、金相、扫描电镜和力学性能进行分析,结果表明:研制的高端淬透性齿轮钢化学成分控制精确,钢水洁净度高,w(O)达到1.0×10-5;热轧态组织为铁素体和珠光体,珠光体片层平均为245nm,晶粒度达到7.5级以上,其淬透性带平均为1.5HRC,满足汽车高端齿轮钢的要求。     

The high temperature transformation of high speed steel

Low tempered hardnesses on high speed steels which had been hardened in vacuum or atmosphere furnaces and gas quenched led to a search for a reaction occurring above 1400°F and probably initiated as a result of the slower cooling rate of the gas quench. A standard TTT evaluation was carried out on Ml, M2 high carbon, M3, and M7 high speed steels, quenching from conventional hardening temperatures, into salt baths maintained at 2000° to 1500°F. Examination of these specimens indicated the presence of a reaction occurring at all temperatures investigated but having its maximum rate at 1700° to 1800°F. The reaction involved precipitation of an MoC/Mo₂C carbide at grain boundaries and within the grains, with the amount of precipitate increasing with time. The precipitation of MoC/Mo₂C is directly related to the loss in tempered hardness and apparently causes this effect by 1) reducing precipitation hardening on tempering, 2) drastically lowering retained austenite contents, and 3) reducing as-quenched hardnesses.     

高速钢轧辊在棒材生产线上的应用

介绍了高速钢轧辊的特性以及优点,并通过对西林钢铁集团轧钢总厂三轧作业区全连续棒材生产线在高速钢轧辊使用过程中,使用条件、事故处理以及使用效果等方面的总结,介绍高速钢轧辊的应用前景与效益。     

Solidification of M2 high speed steel

The freezing process in AISI type M2 high speed tool steel (6 pct W, 5 pct Mo, 4 pct Cr, 2 pct V, 0.8 pct C) was studied by metallographic and thermal analysis techniques. Unidirectional solidification of small laboratory melts in a modified crystal growing apparatus was employed to provide metallographic sections of known macroscopic growth direction. Also cooling curves were obtained on 40 g specimens solidified in thimble crucibles. X-ray microradiography, electron probe scanning techniques, and quantitative microanalysis of dendrites and interdendritic carbides were extensively used to supplement conventional metallography. Carbon and vanadium contents of M2 were varied in order to observe the effect of an austenite and ferrite stabilizer on the thermal analysis curves and microstructure. The nonequilibrium freezing process in M2 includes three major liquid-solid reactions: 1) Liquid → Ferrite, 1435°C; 2) Liquid + Ferrite → Austenite, 1330°C; 3) Liquid → Austenite + M₆C + MC, 1240°C. These reactions account for the as-cast structure of the commercial alloy. The addition of carbon depresses the liquidus (1) and solidus temperatures (3) and narrows the gap between the liquidus (1) and peritectic transformation (2). This gap is eliminated at > 1.39 wt pct C, where the initial freezing reaction is the crystallization of austenite. The accompanying microstructural change is the elimination of σ eutectoid dendrite cores. The addition of vanadium promotes ferrite formation by strongly depressing the peritectic reaction and thus widening the gap between the liquidus and the peritectic.     

Technological developments for high speed casting of sensitive steel grades

Several years ago, in response to the trends in continuous casting technology, Paul Wurth undertook a program to develop and improve casting technology for high quality billet and bloom production. The goal of the program was to simplify the casting machine and design the equipment to be able to produce high quality billets at higher casting speeds. The approach was three-fold: first, design a new oscillation system with more control and flexibility; second, improve the spray conditions to support the higher casting speeds; and third, implement longer mold designs.     

Niobium-Alloyed high speed steel by powder metallurgy

A philosophy for the use of strong carbide formers like niobium in high speed steels is described. It follows the concept of independently optimizing the compositions of the matrix (for maximum secondary hardening potential) and the volume fraction of the blocky carbides (for protection against abrasive wear). Normally, the two are interdependent through the action of the solidification equilibria, but separate control becomes possible when the blocky carbides are formed by a strong carbide former such as niobium. During normal ingot solidification, such strong carbide formers would produce very large primary carbides. This can be avoided by atomization and powder metallurgical processing. In this way, a steel has been produced whose matrix composition is similar to that of AISI M2, and whose primary carbides are all of NbC type. Its composition is 1.3C, 2W, 3Mo, 1.6V, 3.2Nb (wt pct). Because of its high stability, NbC is a much more effective obstacle to grain growth than the normal high speed steel carbides, and this allows substantially higher austenitization temperatures to be used. Despite its leaner composition, the Nb-alloyed steel matches the cutting performance of AISI M2, and its secondary hardening seems to be more persistent at high temperatures.     

高品质齿轮钢28MnCr5的开发

山东莱芜钢铁集团股份有限公司采用"EAF→LF→VD→CC"工艺开发了28MnCr5齿轮钢,通过精确控制钢中C、Si、S、P等元素,得到能够满足成分要求的钢水。试验结果表明:采用该工艺生产高品质汽车用28MnCr5齿轮钢铸坯w(T.O)≤15×10-6,夹杂物种类、形态和尺寸得到有效控制,淬透性满足要求。     

Carbides in M-50 high speed steel

The carbides in M-50 high speed tool steel were studied in detail. The dissolution of carbides as a function of austenitizing temperature, and their precipitation as a function of tempering temperature were characterized by X-ray diffraction and microchemical analysis. The carbides in the annealed steel are M₂₃C₆, M₆C, M₂C, and MC. Upon austenitizing, with increasing temperatures, the carbides dissolve in the order: M₂₃C₆, metastable M₂C, M₆C, and MC. The residual carbides in the heat treated steel are MC and stable M₂C. The solvus temperatures of M₂₃C₆ and M₆C were determined. Upon tempering the hardened steel, with increasing tempering temperatures, carbides precipitate in the order: M₂₃C₆, metastable M₂C, MC, and M₆C. It is shown that the composition of the precipitated metastable M₂C is different from that of the residual stable M₂C and it varies with the tempering temperature.     

Microstructure characteristics of spray-formed high vanadium and cobalt high speed steel

The microstructure of high vanadium and cobalt high speed steel(high-V/Co HSS) and the morphology of its carbides were analyzed by optical microscope(OM),scanning electron microscope(SEM),electron probe microanalysis(EPMA),X-ray power diffraction(XRD),atomic force microscopy(AFM) and single phase erosion(SPE).The results suggest that the as-sprayed high-V/Co HSS has fine equiaxed grains(about 20 μm in size),which were homogeneously distributed.The carbides have two classical morphologies:one is fine particles(about 2 μm in size) distributed along the grain boundaries and the other is needle-like one,distributed on the grain boundaries.There are MC carbides,M2C carbides,M6C carbides and Cr2WC2 carbides in the as-sprayed high-V/Co HSS samples,however,in the as-cast high-V/Co HSS,there are MC carbides and Cr2WC2 carbides only.The SPE results show that there are two types of MC carbides in the as-sprayed HSS:the sphere one and the particle-like one.The former is about 2 μm in size and the latter is less than 1 μm,dispersed inside the grains,quite different from the MC carbides in the as-cast HSS.According to the AFM results,the skeleton-like M6C carbides of the as-sprayed high-V/Co HSS are embedded in the matrix along the grain boundaries.It is found that there are sharp membrane pieces on the carbides.Some small bamboo-shoot-like MC carbides grow from the matrix and are dispersed inside the grain.Those larger MC carbides are spherical particles embedded at the grain boundary junctions.