轧辊开裂原因浅析  

Elementary Analysis on the Causes of Roll Cracking

作　　者：田志平 王会强[1] 王浩伟 郝策 柯稳 TIAN Zhiping;WANG Huiqiang;WANG Haowei;HAO Ce;KE Wen(college of Mechanical and Electrical Engineering,Hebei Agricultural University,Baoding 071001,Hebei China)

机构地区：[1]河北农业大学机电工程学院,河北保定071001

出　　处：《热处理》2020年第5期61-64,共4页Heat Treatment

基　　金：河北省高等学校科学技术研究重点项目(ZD2017035)。

摘　　要：一批42CrMo钢轧辊表面淬火后发现其表面有裂纹。为分析开裂的原因,对开裂轧辊进行了化学成分分析、金相检验、断口试验、硬度测定和低倍检验。结果显示:轧辊心部由于调质处理的淬火冷却速率不足,形成了强度较低、塑性较差的不良组织上贝氏体,加之轧辊在调质前未进行正火处理,内应力较大,产生了裂纹;随后表面淬火时温度过高,应力进一步增大,裂纹扩展导致轧辊开裂。A batch of 42CrMo steel rolls were found to exhibit surface cracks after being surface hardened.The cracked roll was subjected to chemical composition analysis,metallographic examination,fracture test,hardness measurements and macro-check for the purpose of discovering the cause of the roll cracking.The results showed that undesired upper bainite which had lower strength and poor plasticity and resulted from insufficient cooling in quenching and tempering presents in core of the roll,in addition,the rolls were not normalized before quenching and tempering,had larger internal stress,resulting in initiation of crack.Subsequently,the stress increases further due to excessive temperature in surface hardening,causing crack extension and the roll cracking.

关 键 词：42CRMO钢 应力 开裂 上贝氏体 

分 类 号：TG174[金属学及工艺—金属表面处理]