20CrMnTi钢花键轴开裂失效分析

Analysis on Cracking of 20CrMnTi Steel Spline Shaft

经渗碳、淬火和回火处理的20CrMnTi钢花键轴在使用中其轴肩的根部开裂。对开裂的花键轴进行了宏观、微观分析和硬度测试。结果表明,花键轴的显微组织没有达到要求,导致韧性降低;轴肩根部不是圆角而是直角,造成应力集中,最终导致花键轴开裂失效。

Shoulder root of 20CrMnTi steel spline shaft subjected to carburizing,hardening and tempering cracked in service.The cracked spline shaft was macro-and micro-examined,and hardness tested.The results show that microstructure of spline shaft do not conform with the requirement,resulting in lower toughness,moreover,the shoulder root is not filleted corner but right angle causing stress concentration,leading to the spline shaft cracking. Key wodrs： 20CrMnTi steel;spline shaft;cracking;microstructure