高强度R400HT钢轨热处理工艺优化

Optimization of heat treatment process for high strength steel rail R400HT

以高强度过共析R400HT钢轨为研究对象,对R400HT钢轨冷却过程中组织转变和硬度进行测试分析,建立了R400HT钢轨的CCT曲线。在此基础上制定了R400HT钢轨的主要热处理工艺参数范围,并进行热模拟正交试验。结果表明,R400HT钢轨最优热处理工艺为入口温度780~800℃、出口温度480~510℃、冷却速率3.0~3.5℃/s。按照上述工艺进行了工业试制,试制R400HT钢轨踏面硬度425.5~428.3 HBW,抗拉强度1425~1440 MPa,显微组织为珠光体,达到了预期目标。

Taking high strength eutectoid rail R400HT as research object,and the microstructure transformation and hardness properties of the R400HT steel rail during cooling were tested,and the CCT curves of the R400HT steel rail was established.On this basis,the range of main heat treatment process parameters of the R400HT steel rail was developed,and the thermal simulation orthogonal experiment was carried out.Through statistical analysis of the test results,the optimal heat treatment process scheme of the R400HT steel rail was obtained.The results show that the optimal treatment process of the R400HT rail steel is that the inlet temperature of 780-800℃,the outlet temperature of 480-510℃,and the cooling rate of 3.0-3.5 ℃/s.The industrial trial production is carried out according to the above process.The hardness of the trial R400TH rail is 425.5-428.3 HBW,the tensile strength is 1425-1440 MPa,and the microstructure is pearlite,which achieves the expected goal.