以自行开发的贝氏体轴承钢为研究对象,采用热模拟试验机在变形温度900~1 200 ℃、应变速率0.01~5 s^-1条件下进行单道次热压缩试验,研究了该钢的热压缩变形行为,基于真应力、真应变数据,建立热变形本构方程,并绘制热加工图。结果表明:当变形温度不低于1 000 ℃、应变速率低于0.1 s^-1时,试验钢在热压缩过程中的动态再结晶较明显。在相同应变速率下,变形温度越高,峰值应力越小,到达峰值应力的真应变也越小;在相同变形温度下,应变速率越大,峰值应力越大,达到峰值应力的真应变也越大。试验钢的变形激活能为479.119 kJ·mol^-1,明显大于传统GCr15马氏体轴承钢,说明在相同变形温度下试验钢更难以变形。试验钢适宜的热加工区间为变形温度900~1 100 ℃、应变速率1.4~2 s^-1。

Taking self-developed bainite bearing steel as research object, the single pass hot compression tests were carried out with thermal simulator at deformation temperatures of 900-1 200 ℃ and strain rates of 0.01-5 s^-1, and the hot compression deformation behavior of the steel was studied. The constitutive equation was established based on true stress and true strain data, and hot processing map was drawn. The results show that when the deformation temperature was not lower than 1 000 ℃ and the strain rate was below 0.1 s^-1, the dynamic recrystallization of the test steel during hot compression deformation was obvious. At the same strain rate, the higher the deformation temperature, the smaller the peak stress and the true strain at the peak stress; at the same deformation temperature, the greater the strain rate, the greater the peak stress and the true strain at the peak stress. The deformation activation energy of the test steel was 479.119 kJ·mol^-1 and was significantly higher than that of the traditional GCr15 martensitic bearing steel, indicating that the test steel was more difficult to deform at the same deformation temperature. The suitable hot processing range of the test steel was deformation temperature of 900-1 100 ℃ and strain rate of 1.4-2 s^-1.