Abstract:  Tempering of the holding time after different temperature of clad steel plate for saw blade steel has been carried out, the hardness of cladding plate and hase plate and the microstructure evolution are measured and observed. The results show that the lath martensite in substrate steel Q345 coarsens gradually during tempering, but the characteristics of lath can be retained after tempering at higher temperatures. However,the acicular martensite in cladding plate steel 45Mn2V degrades faster than that in substrate steel, so the characteristics of acicular could not be observed after tempering at 400℃ ., which results in the decreasing of hardness of cladding plate steel 45Mn2V after tempering is larger than that of substrate steel Q345. Therefore,the tempering temperature of the clad plate should not exceed 400℃. On the other hand,because of the high carbon content, the precipitation of carbides in steel 45Mn2V cladding plate is faster and more during tempering, so high hardness can still be maintained after tempering for 8 hours,while the Q345 substrate plate has obviously softened. Therefore,the optimum performace of steel can be got by oil quenching at 860 ℃ for 5 min and tempering at 360 ~ 390℃  for 6 h.

Key words: Clad Steel Plate, Steel for Saw Blade, Tempering, Microstructure Evolution ,

摘要： 对复合锯片用钢进行了不同温度和保温时间的回火处理,分别测定和观察了覆层与基板的硬度和显微组织。结果表明:Q345钢基板的板条马氏体在回火过程中逐渐粗化,但其基本特征经较高温度回火后仍能保留下来,而覆层45Mn2V钢的针状马氏体退化速度较快,400℃回火后已观察不到针状特征,导致回火后其硬度下降的趋势大于Q345钢基板,因此复合板的回火温度不宜超过400℃。另一方面,由于碳含量较高,45Mn2V钢覆层在回火过程中碳化物的析出较快且析出量较多,故经过8 h回火后仍能保持高的硬度,而Q345钢基板已经发生明显的软化,因此860℃保温5 min油淬,360～390℃保温6 h回火可获得最佳性能。