同批次液压油缸外筒在服役中先后发生爆裂事故。利用宏观和微观检验、化学成分分析和硬度测试等方法对油缸外筒爆裂的原因进行了分析。结果表明: 主要原因是存在焊接裂纹, 造成应力集中和氢元素富集, 在工作应力和焊接残余应力的共同作用下, 发生了氢致延迟脆性断裂。

Two outer canisters of the same batch of hydraulic oil cylinder bursted successively in use. Macro and micro examination, chemical composition analysis, hardness testing and so on were carried out to analyze the bursting reason of oil cylinder. The results showed that the weld cold cracking existed on the oil cylinder. These preexisting cracks made stress concentration, so the hydrogen in material moved to the crack tip and was enriched due to stress induced diffusion . While the hydrogen content come to the up-limited of the fracture hydrogen content under work stress and welding residual stress, finally,the hydrogen-induced delayed brittle fracture occurred in the oil cylinder.