路灯灯管支架断裂失效分析

Failure Analysis of the Street Lamp Bracket

目的研究路灯灯管支架出现批量断裂失效的原因。方法通过化学成分分析、力学性能分析、断口扫描分析、金相组织分析、能谱分析等测试手段,对灯管支架的断裂模式及失效原因进行了分析。结果材料中存在贯穿性的带状硅、钙类非金属夹杂物,严重破坏了组织连续性;同时,晶界析出过多链状或断续网状三次渗碳体,导致了晶界脆性增大。结论材料内部缺陷会严重降低材料综合力学性能,通过对原材料冶炼工艺及后续热处理工艺进行改进,问题得到了有效解决,杜绝了此类失效事故再次发生。

This article aims to investigate the failure reasons of the batch street lamp bracket. The fracture modes and the failure reasons were analyzed by means of chemical composition analysis,mechanical performance analysis,SEM analysis,metallographic examination and energy spectrum analysis. It was found that the silicon and calcium-based nonmetallic inclusions throughout the material severely damaged the continuity of the metallurgical structure. At the same time,the chain or intermittent excessive tertiary cementite which separated from grain boundary increased the brittleness of grain boundaries. Internal defects in materials could severely degrade the mechanical properties,but the problem has been effectively resolved after improving the smelting process and subsequent heat treatment process,and such failure accidents never happened again.