高强螺栓断裂原因分析

对断裂的高强度螺栓断口及其腐蚀产物、螺栓表面存在的微裂纹进行了观察分析；对螺栓材料进行了热处理、氢脆敏感性和力学性能试验。结果表明，引起断裂发生的裂纹源─—微裂纹是Ｃｌ￣－应力腐蚀及氢脆交互作用的结果。断裂螺栓材料变脆是由于时效致使晶界产生铁铬碳化物偏聚引起的。对断口形貌和断裂过程用断裂力学方法提出了解释。

Analysis of fracture causes of high strength bolts

Analyses and obervations of the fracture of a failed high-strength bolt and its corrocion products and tiny cracks on its surface were made. For the bolt material, heat treatment and hydrogen embrittlement sensitiveness testing and mechanical testing were conducted. The results indicate that the tiny cracks-a crack-ing source causing the bolt failed-results from the interaction of Cl￣-stress corrcoion and hydrogen embrittle-ment, and the embrittlement of the failed bolt material is contributed to the fact that carbides of Fe-Cr are segregated on the grain beundries by aging.The fracture appearance and fracture course are explained by fracture mechanics.