40CrNiMoA螺杆断裂分析

Analysis of 40CrNiMoA screw fracture

针对40CrNiMoA螺杆在斜拉车间张拉工段发生断裂问题,通过化学成分检测、扫描电镜观察、金相观察、常规拉伸试验力学性能分析等对断裂原因进行了研究。结果表明:断裂螺杆的探伤、化学成分正常,螺杆断裂方式为脆性断裂,力学性能不符合标准,回火时间不够,金相组织不均匀导致螺杆发生断裂。

Aiming at fracture problem of 40CrNiMoA screw in tension section of cable-stayed workshop,the cause of fracture was studied by chemical composition detection,SEM observation,microstructure observation,and mechanical property analysis of conventional tensile test.Results show that flaw detection and chemical composition of fractured screw is normal,screw fracture mode is brittle fracture,mechanical properties do not meet standard,and screw fracture is caused by uneven microstructure due to insufficient tempering time.