高温变形GCr15连续冷却相变及显微组织分析

为合理确定GCr15轴承钢的轧后冷却工艺,利用Gleeble1500热模拟实验机,模拟830℃终轧的变形过程,测定GCr15轴承钢的动态CCT曲线;利用光学显微镜、扫描电镜等分析了冷却速度对珠光体片层厚度和网状碳化物析出的影响规律.实验结果表明:在一定的冷却速度范围内,随着冷速的增加珠光体片层变薄,当冷却速度过大时,会产生一种粗大的类珠光体组织;当冷却速度为10℃/s左右时,可以获得细片状珠光体组织,且可有效减少网状碳化物的析出.

Analysis of Continuous Cooling Transformation and Microstructure of Hot-Formed GCr15 Steel

Gleeble1500 thermal simulation machine was used to simulate the hot rolling process of GCr15 bearing steel with the aim to reasonably determine the cooling process after rolling, where the final-pass temperature was 830°C. The dynamic CCT curve was therefore given. Optical microscopy and SEM were employed to investigate the influence of cooling rate on the thickness of pearlite lamella and network carbide precipitation, and the results showed that the thickness of pearlite lamella thins with increasing cooling rate within a certain range of cooling rate, while a coarse pearlite-like structure takes place if the cooling rate is too high. When the cooling rate is about 10°C/s, the pearlite lamella structure is obtainable and the quantity of network carbide precipitation can be decreased efficiently.