采用宏观观察、硬度分析与金相检验等方法对汽车转向机构的滑动轴套破裂失效原因进行了分析。结果表明:滑动轴套热处理工艺不合理导致硬度差异悬殊及材料内部存在微裂纹等缺陷,从而降低了滑动轴套承受冲击载荷的能力,且在使用过程中又保养不善,锈蚀严重,这些是转向机构发生故障的主要原因。

The failure reasons of sliding axle sleeve in automobile steering mechanism were analyzed using macroscopical observation,metallographic analysis and hardness testing. It was shown that the unreasonable heat treatment induced the great disparity of hardness and microcrack inside material,debased the ability of enduring impact of sliding sleeve. The steering mechanism was not maintained well and rust badly. All above factors led to the failure of automobile steering mechanism.