高温均匀化处理对1.3C-5Cr-0.7Mo-0.6V钢中碳化物形貌及力学性能的影响

Effect of high temperature homogenization on carbide morphology and mechanical properties of 1.3C-5Cr-0.7Mo-0.6V steel

为改善1.3C-5Cr-0.7Mo-0.6V钢中一次碳化物形貌,在1170℃下对其进行了不同时间的高温均匀化处理并水淬至室温,之后对其进行退火-淬火-回火处理。采用扫描电镜(SEM)、透射电镜(TEM)、X射线衍射仪(XRD)及压缩试验等方法对不同时间高温均匀化处理后样品的形貌、物相及力学性能进行分析。结果表明,高温均匀化处理可以有效改善一次碳化物的尺寸及形貌,由网状变为均匀分布的小球状。试验钢在高温均匀化处理3 h时取得了抗压强度4703 MPa、工程应变37.3%的压缩力学性能;较未均匀化处理的钢而言,其压缩强度和压缩应变分别提升14.5%和30.8%。

To improve the primary carbides of 1.3 C-5 Cr-0.7 Mo-0.6 V steel,high temperature homogenization(HTH)was carried out at 1170℃ for different time,followed by water quenching to room temperature.Subsequently,a conventional heat treatment process,annealing,quenching and tempering,was further employed to obtain the final microstructure of the steel.The microstructure and mechanical properties of the specimens were analyzed by means of scanning electron microscopy,transmission electron microscopy,X-ray diffraction and compression tests.The results indicate that the size and morphology of the primary carbide are considerably improved by HTH.The network carbides are refined into small and spheroidal ones that distribute homogenously on the matrix.An outstanding compression mechanical property,compression strength of 4703 MPa and engineering strain of 37.3%,is obtained for the specimen due to 3 h HTH treatment.Compared with the untreated steel,the compression strength is enhanced by 14.5%,accompanied by an increase of 30.8% of the compression strain.