30Cr2Ni4MoV钢晶粒细化工艺方法研究

Research on Grain Refinement Techniques of 30Cr2Ni4MoV Steel

利用金相显微镜对不同热处理工艺下的显微组织进行观察,研究低压转子钢30Cr2Ni4Mo V晶粒度变化的规律。实验结果表明,粗大的奥氏体晶粒经临界区侧正火+850℃×3 h淬火后,30Cr2Ni4Mo V钢试样的晶粒度等级最高可达8.0级;粗大的奥氏体晶粒经高温正火+850℃×3 h淬火后,30Cr2Ni4Mo V钢试样的晶粒度等级可达6.5级。上述热处理工艺经二次正火加热后晶粒细化效果更佳。

The microscopic structures of 30Cr2Ni4 Mo V steel under different heat treatments are investigated by the metallographic microscope. The change rule of grain size is researched for the low pressure rotor steel 30Cr2Ni4 Mo V.The experimental results show that the grain size grade of 30Cr2Ni4 Mo V steel is up to grade 8 after critical region side normalizing ＋ quenching at 850 ℃ × 3 h for thick austenite grain,and the grain size grade of 30Cr2Ni4 Mo V steel is up to grade 6. 5 after high temperature normalizing ＋ quenching at 850 ℃ × 3 h for thick austenite grain. After the above heat treatment process is performed two times of normalizing,grain refinement effect is better.