某20Cr2Ni4A钢轴开裂原因分析  

Cause Analysis on Cracking of a 20Cr2Ni4A Steel Shaft

作　　者：高学平 GAO Xueping(Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials,Ministry of Education,Shandong University,Jinan 250061,China;School of Materials Science and Engineering,Shandong University,Jinan 250061,China)

机构地区：[1]山东大学材料液固结构演变与加工教育部重点实验室,济南250061 [2]山东大学材料科学与工程学院,济南250061

出　　处：《理化检验（物理分册）》2020年第6期42-47,共6页Physical Testing and Chemical Analysis(Part A:Physical Testing)

摘　　要：某20Cr2Ni4A钢轴经两次渗碳处理,静置4d(天)后,发生开裂。采用宏观分析、化学成分分析、断口微观分析、金相检验、气孔及夹杂物分析等方法对钢轴的开裂原因进行了分析。结果表明:不合理的热处理工艺使钢轴产生了过大的内应力,在表层的夹杂物和气孔等缺陷处产生了应力集中。裂纹在缺陷处萌生并扩展,最终导致钢轴发生静置开裂。A 20Cr2Ni4 Asteel shaft was carburized twice and cracked after standing for four d(days).The cracking causes of the steel shaft were analyzed by means of macro analysis,chemical composition analysis,fracture micro analysis,metallographic examination,blowhole and inclusion analysis.The results show that the unreasonable heat treatment process caused the excessive internal stress of the steel shaft,and the stress concentration was formed at the defects such as inclusion and porosity.The cracks initiated and propagated at the defects,which eventually led to the static cracking of the steel shaft.

关 键 词：20CrNi4A钢轴 开裂 夹杂物 气孔 冶金缺陷 带状组织 

分 类 号：TG115[金属学及工艺—物理冶金]