合成氨高压废热锅炉环缝泄漏性裂纹成因分析

THE ANALYSIS OF CAUSE FOR LEAKING CRACKS IN THE ANNULAR WELD METAL OF HIGH PRESSURE-WASTE HEAT BOILER

焊缝的泄漏性裂纹问题在国内外均时有发生,严重威胁着工厂的正常生产与安全.就四川沪天化公司合成氨一分厂高压废热锅炉管板管箱环缝在安装运行仅一年多即发生泄漏起火,焊补后不到一年再次出现严重泄漏事故,通过工况调查,钢材焊接性分析,金相和断口分析,焊接结构应力测试等,对开裂原因进行了分析研究,认为严重的氢渗透、氢诱导以及长期高温工作的再热倾向和应力腐蚀是开裂的基本原因.^为割除原环缝,重新焊接提供了参考依据.

There are many leaking cracks of weld metal in 2 1/4 Cr-Mo synthetic ammonia equipment in the world, which are dangerous to common production and safety of factories. A failure analysis was presented according to the failure of a high pressure waste heat boiler in the factory in the southwest of China. The tube-plate annular weld metal in the boiler leaked and fired after working more than one year, and this weld metal leaked again after repair welding in less than one year. Through the analysis of work condition, steel weldability, metallurgical, fracture surface and welding structure stress, etc. , the cracking reason was discussed and proposition was given.