900A UIC54钢轨全长淬火工艺开发

文章介绍了900A UIC54钢轨淬火工艺的开发,通过产品性能检验,表明900A UIC54钢轨淬火性能稳定,质量好,满足客户要求。取得良好的经济效益。     

Si-Cr-Nb高强钢轨钢的研制

在实验室将Si-C-Nb钢轨钢与UIC900A、U71Mn等钢轨钢进行了对比试验研究.各钢种的力学性能测定和热模拟试验表明,Si-Cr-Nb钢轨钢具有良好的强韧性,适合于全长淬火,具有较好的焊接性能.     

Si-Cr-Nb高强钢轨钢的研制

在实验室将Si-Cr-Nb钢轨钢与UIC900A、U71Mn等钢轨钢进行了对比试验研究。各钢种的力学性能测定和热模拟试验表明，Si-Cr-Nb钢轨钢具有良好的强韧性，适用于欠速淬火，具有较好的焊接性能。工业性试验验证了实验室的研究结果，Si-Cr-Nb钢轨有望获得良好的性能。     

离线热处理钢轨中白亮层的产生和控制

文章主要以C900A材质的钢轨为例,结合包钢轨梁厂电淬火生产线设备改造后,开发欧洲标准热处理钢轨实验中的相关数据,对白亮层的微观组织结构、产生原因和产生位置进行分析,简述影响白亮层产生的因素,并提出控制措施。     

铁路大发展，钢铁要跟上

笔者在包钢轨梁厂工作期间,参加了我国的第一支60公斤/米钢轨的试制和钢轨的全长淬火实验研究,该厂生产的50公斤/米、60公斤/米钢轨和钢轨的全长淬火实验研究曾获得国家金奖和部级成果二等奖。为超前研究我国高速铁路用钢轨生产技术,鞍钢、     

百米淬火钢轨平直度控制技术研究

平直度是百米钢轨重要指标之一.钢轨平直度好坏直接关系到列车乘坐舒适性及运行安全性.文章重点研究了百米淬火钢轨生产过程中轧制、淬火冷却、矫直过程中平直度工艺控制.通过在万能连轧机上微张力轧制,精轧机延伸平衡轧制,淬火冷却采用轨头腰底平衡冷却技术,矫直采用轻压下技术,生产出满足高速铁路平直度要求的百米淬火钢轨.     

鞍钢建设钢轨全长淬火生产线的可行性分析

叙述了国内钢轨全长淬火技术发展情况和可供借鉴的国外钢轨热处理四个基本工艺,着重对鞍钢建钢轨全长淬火生产线的可行性进行了实事求是的分析,并提出了具体实施建议。鞍钢开发生产全长淬火钢轨是关系到鞍钢振兴,大型厂发展的战略性举措,已构成“八五”期间后3年亟待解决的重要课题。     

包钢900A、BNbRE重轨力学性能的研究

随着铁路高速化的发展，对钢轨的质量也提出了更高要求。《EN铁路用钢轨标准》中断裂韧性、裂纹扩展速率和金属轴向疲劳性能指标已先后被世界上很多国家采纳和应用，作为国际招标的标准。本文主要针对包钢生产出口900A钢轨和BNbRE高速轨的断裂韧性、裂纹扩展速率和金属轴向疲劳性能进行研究。     

淬火轨成分调整及工艺研究

通过研究目前铁路上使用的淬火轨,对包钢离线全长淬火钢轨成分进行调整,并制订了CPD3、CBNbRE热处理工艺参数,使淬火钢轨的综合性能明显提高.     

关于钢轨油中整体淬火生产线的探讨

包钢要从苏联引进年产25万吨钢轨油中整体淬火生产线。为作好引进的技术准备工作,论证了钢轨热处理强化的远景,淬火轨的经济效益。指出了筹建热处理生产线是加速铁路运输发展急需采取的对策之一。作者根据掌握的苏联各生产厂淬火轨试验、生产方面的资料,论述了整体油中淬火工艺的优点,同时也指出了该工艺存在的、有些是不可克服的缺点,供同志们参考。最后,根据世界淬火钢轨发展趋势及包钢进行的、经冶全部鉴定的“钢轨整体加热全长淬火新工艺”的经验,对包钢的钢轨热处理生产线提出了初步设想。     

Differential heat treatment of rails

Experimental data are presented regarding the differential quenching of rails in air and the properties of the first batch of differentially quenched rail (length 100 m) subjected to certification tests. The prospects for the new class of rails are assessed.     

U75V 75 kg/m钢轨淬火工艺研究

主要介绍了U75V 75 kg/m全长淬火钢轨的生产,包括化学成分的控制,部分淬火工艺设备的重新设计和改造,淬火工艺参数的调整和试验.在大秦线路试铺证明:性能稳定,易于焊接,耐磨性良好.     

Fragmentation of the grain structure of quenched rails

Transmission electron microscopy permits layer-by-layer structural analysis (along the central axis and in the direction of the rounded corner) of bulk-quenched and differentially quenched rails at distances of 0, 2, and 10 mm from the working surface. Regardless of the direction and the distance from the working surface, the structure of all the rails consists of plate-pearlite grains and ferrite grains, containing cementite particles of different shape (ferrite–carbide mixture) and grains of structure-free ferrite (ferrite grains that do not contain carbide phase, grain-boundary ferrite). The morphology and defect substructure of the phases are studied; the locations of the stress concentrators are established. Formulas are derived for the fragmentation parameters of the grains in the ferrite–carbide mixture as a function of the heat-treatment conditions and the distance from the working surface.     

44Si2CrV钢弹簧的室温蠕变

试验结果得出,44Si2CrV钢弹簧经淬火+中温回火处理并除掉表面脱碳层后,在室温下所受应力超过临界蠕变应力值时即发生蠕变;钢的抗拉(或剪切)强度越高,临界蠕变应力越高。44Si2CrV钢900℃淬火,500℃回火,临界蠕变应力 τ_cc =700 MPa;900℃淬火,380℃回火, τ_cc =800 MPa。蠕变开始时的塑性变形速率较大,之后急剧减小,在一定应力下保持一定时间后蠕变停止。经长时间压缩,蠕变变形已经停止的弹簧,于200℃保温2 h后空冷,弹簧的自由高度伸长,并且在原来的应力下加载,弹簧蠕变又重新开始。     

热处理工艺对海洋工程用高强度耐低温H型钢组织及性能影响

摘要：以热轧耐低温H型钢为研究对象,采用光学显微镜、扫描电镜、透射电镜分析和力学性能测试等手段,研究了完全淬火和亚温淬火对试验钢微观组织和力学性能的演变规律。结果表明,试验型钢经780℃亚温淬火+600℃回火处理后,形成回火索氏体+铁素体的网状组织;试验型钢900℃淬火+600℃回火处理后,转变得到具有马氏体位向的回火索氏体,碳化物分布更加细小均匀,位错密度下降。2种热处理工艺制备H型钢综合力学性能优良,屈服强度均达到500MPa以上,900℃淬火+600℃回火处理后钢的屈服强度和抗拉强度更高。-40℃低温冲击韧性比热轧状态下出现大幅度提高,随着淬火温度升高冲击功更加稳定。     

Effect of Heat Treatment on Microstructure, Mechanical Properties and Fracture Behaviour of Ship and Dual Phase Steels

 Grade A (GA) and high strength steel DH36 ship steels possessing different chemical compositions were used, and strength properties of GA steel and DH36 steel were compared. Additionally, 4 types of dual phase (DP) steels with different martensite volume fractions (MVFs) were produced from GA steel by means of heat treatment and they were compared with other steels through conducting microstructure, microhardness, tensile and impact tests. The fracture surfaces of specimens (DH36, GA and DP steels) exposed to tensile and Charpy impact tests were investigated by scanning electron microscope. Furthermore, it was found that the specimens quenched from 800 and 900 ℃ had better strength than DH36 steel. The tensile test results indicated that the tensile strength of DP steel water quenched from 900 ℃ was 3 times that of GA steel and twice that of DH36 steel.     

Production of powders of cast iron shavings and special features of production of components from these powders. III. Structure and strength of heat-treated alloys

Conclusions Quenching the specimens from 800°C does not lead to the redistribution of the carbide in the volume of the alloys of the iron-cast iron system. The most homogeneous structure of the alloys is formed only in quenching from 900°C. However, quenching from 1000°C increases the size of voids and causes supinating of the alloys, although their homogeneity increases.Heat treatment increases the tensile strength of the alloys which contain 10–50% of low-alloy cast iron. The alloys quenched from 800°C have the maximum strength after tempering of 300°C, whereas the alloys quenched from 900 and 1000°C with a maximum strength at tempering temperatures of 250 and 200°C, respectively.The highest hardness was recorded for the alloys after quenching from 900°C. All the alloys quenched from 800, 900, and 1000°C are characterized by sufficiently higher hardenability to a depth of 4mm.An increase of the tempering temperature of the alloys in the range 200–300°C reduces their impact toughness. This fact is not in agreement with the generally recognized interpretations. However, an increase of the cast iron content usually greatly reduces the KC value of the specimens, regardless of the quenching and tempering temperatures.Translated from Poroshkovaya Metallurgiya, No. 1(325), pp. 47–53, January, 1990.