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采用Gleeble3800热/力模拟试验机研究了终轧工艺和轧后冷速对GCr15Si Mn轴承钢相变组织转变的影响,结合动态CCT曲线及不同工艺下的组织与显微硬度分析。结果表明:变形速率对试验钢的组织转变没有太大影响;随着变形量的增加,二次碳化物析出增多,珠光体转变温度升高,珠光体转变量增加且球团直径减小;当冷速由1℃/s升高为5℃/s时,晶界处二次碳化物析出明显减少,网碳基本消失,组织将会出现马氏体,马氏体转变温度为163℃,终轧后控制冷却速度可以达到控制组织转变类型的目的。
The effects of the finish rolling process and cooling rate after cold rolling on the transformation of the microstructure of GCr15SiMn bearing steel were investigated by Gleeble3800 thermal / mechanical simulation test machine. The dynamic CCT curves and the microstructure and microhardness of the GCr15SiMn bearing steel were analyzed. The results show that the deformation rate has no significant effect on the microstructure and transformation of the test steel. With the increase of deformation, the precipitation of secondary carbides increases, the pearlite transformation temperature increases, the amount of pearlite transformation increases and the diameter of the pellets decreases. When the cooling rate increases from 1 ℃ / s to 5 ℃ / s, the precipitation of secondary carbides at the grain boundary obviously decreases and the net carbon disappears, the microstructure will appear martensite, the martensite transformation temperature is 163 ℃, and the final Controlled cooling rate after rolling can achieve the purpose of controlling the type of tissue transformation.