超快冷终冷温度对轴承钢棒材组织性能影响

以GCr15轴承钢棒材为研究对象,研究了超快速冷却终冷温度对其组织性能的影响.研究发现:高温终轧后以大于100℃/s的冷却速度超快速冷却到一定温度后缓冷到室温,随着超快冷段终冷温度降低,珠光体球团直径和片层间距减小;终冷温度过高只能使晶界碳化物厚度减薄但不能抑制其呈网状析出,降低终冷温度到715℃以下就可以得到抑制了网状碳化物析出的细片层珠光体型组织;随着终冷温度继续降低显微硬度增加并有退化珠光体产生,其显微硬度可达到426 HV.

Influence of UFC Final Cooling Temperature on Structure and Microhardness of Bearing Steel Rod

GCr15 bearing steel rod was investigated to analyze the influence of UFC (ultra fast cooling) final cooling temperature on its structure and microhardness. It was found that along with UFC temperature drop the diameter of spheroidal pearlites and interval of lamellar pearlites both decrease if the UFC rate is higher than 100°C/sec after high-temperature final rolling to cool the workpiece to a certain degree then it is slowly cooled to ambient temperature. The higher temperature of final cooling can thin down the intercrystalline carbides but cannot suppress the precipitation of network carbides. However, the thinly lamellar pearlite structure is available by the precipitation of suppressed network carbides if the final cooling temperature is lower than 715°C, and the microhardness of workpiece increases up to 426 HV with degenerated pearlites taking place if the final cooling temperature further decreases.