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用定量金相法研究了30Cr2Ni4MoV低压转子钢在不同原奥氏体晶粒度条件下(1.0级与6.0级)以30℃/h加热至840℃保温10 h后过冷奥氏体在不同等温温度(575、600、625℃)下珠光体转变量与等温时间的关系。根据试验结果拟合得到表征珠光体转变动力学的Avrami方程,进而绘制了分别适用于低压转子锻后热处理与性能热处理的30Cr2Ni4MoV钢珠光体等温转变的时间-温度-转变量曲线(TTT曲线)。在拟合得到考虑原奥氏体晶粒度因素的修正Avrami方程的基础上,比较了不同的原奥氏体晶粒度对珠光体转变的影响。
The quantitative metallographic method was used to study the microstructure and mechanical properties of 30Cr2Ni4MoV low-pressure rotor steel with different austenite grain sizes (1.0 and 6.0) heated at 30 ℃ / h to 840 ℃ for 10 h, and then undercooled austenite at different isothermal temperatures 575,600,625 ° C) pearlite transformation volume and isothermal time relationship. According to the experimental results, the Avrami equation characterizing the kinetics of pearlite transformation was fitted and then the time-temperature-transformation curve (TTT curve) of the isothermal transformation of 30Cr2Ni4MoV steel pearlite, which was suitable for heat treatment and heat treatment of low-pressure rotor respectively, was drawn. On the basis of the modified Avrami equation which is fit to the original austenite grain size, the effect of different original austenite grain size on the pearlite transformation is compared.