高压熔体管异种钢焊接接头失效分析

Failure Analysis of a Dissimilar Steel Welded Joint of High Pressure Fusion Tube

某厂一台压力容器制造完毕进行水压试验时,与其连接的高压熔体管异种钢焊接接头处发生渗漏失效事故。针对失效接头,采取宏观检查、材料化学成分分析、金相观察、显微硬度测试等方法进行了分析。结果表明,焊接施工操作不当引起的接头处组织异常、材料韧性降低及螺纹孔位置设计不当是引起接头泄漏失效的主要原因。

The leakage failure of dissimilar metal welded joint of high pressure fusion tube connected to a pressure vessel occurred when the pressure vessel was undergoing water pressure test after manufacture. The failure was analyzed by the means of macro inspection, material chemical composition analysis, metallographic observation and microhardness test. The analytical results showed that the abnormal basic structure caused by improper operation, lowing material toughness and improper design of thread hole were the main reasons for the welded joint crack failure.