火车轮轧制用主轧辊环状裂纹原因分析

Analysis on the Causes of Ring Cracks in Main Roller for Rolling Train Wheel

主轧辊热处理后在精加工过程中发现内孔台阶处有环状裂纹。通过宏观分析、化学成分检测、力学性能试验、显微组织分析、扫描电镜断口分析等手段,对主轧辊开裂原因进行了分析。结果表明,主轧辊开裂是由于锻造局部控制不当造成晶界弱化,随后在热处理淬火时扩展产生周向环状开裂,属典型高温热裂纹。

After heat treatment,ring crack has been found in the inner hole step of main roller during finishing.By means of macroscopic analysis,chemical composition test,mechanical property test,microstructure analysis,scanning electron microscope fracture analysis,the cause of main roll cracking has been analyzed.The results show that the cracking of the main roll is caused by the weakening of grain boundary due to the improper local control of forging,and then the circumferential ring cracking occurs during quenching,which is a typical thermal crack at high temperature.