摘要
某安装工程中作为承力构件的17-4PH不锈钢拉杆在使用过程中发生断裂,对失效拉杆进行化学成分分析、断口形貌和金相组织观察以及力学性能测试,并与完好拉杆进行了对比分析。结果表明:不锈钢拉杆是在腐蚀及应力的共同作用下发生了应力腐蚀断裂;由于热处理不当,导致失效拉杆中块状δ-铁素体的大量存在,时效过程中晶界上碳化物的析出造成材料抗腐蚀能力下降,以及材质"硬脆"共同导致拉杆发生断裂。
A 17-4PH stainless steel rod fractured during service.Chemical composition analysis,fracture surface and microstructure examination and mechanical property testing were carried out on the failed rod,and the results were compared with those of an undamaged one.The results show that the stainless steel rod was stress corrosion fracture under the co-effect of the corrosion and stress.The corrosion resistance was declined because of the carbide precipitating in the grain boundary during aging and the massively existed δ-ferrite block caused by the improper heat treatment,which together with the ＂hard and brittle＂ material resulted in the failure of the rod.
出处
《失效分析与预防》
2010年第3期182-186,共5页
Failure Analysis and Prevention
关键词
不锈钢
拉杆
断口
失效分析
stainless steel
rod
fracture
failure analysis
