风电铁塔高强度螺栓断裂失效分析

Failure Analysis on High Strength Bolts of Power Tower

本文对断裂螺栓进行化学成分分析、力学性能检测、断口形貌和金相组织观察,并对其断裂原因进行分析。结果表明:断裂螺栓表面存在全脱碳现象,且脱碳层极不均匀,螺栓表面的抗应力和抗疲劳强度下降明显,在使用过程中产生的交变应力冲击下,裂纹从螺纹尖角应力作用点开始出现并不断地快速扩张,从而产生断裂失效。

The chemical composition, mechanical properties, fracture morphology and microstructure of the broken bolt were analyzed, and the fracture reasons were analyzed in this paper. The results showed that there was complete decarburization on the surface of broken bolt, and the decarburization layer was very uneven, which significantly reduced the stress resistance and fatigue strength of the bolt surface. Under the impact of the alternating stress generates in the process of use, the crack began to appear at the stress action point of the sharp corner of the thread and continued to expand rapidly, resulting in fracture failure.