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对一台材质为16MnR的氮气储罐进行首次全面检验时发现封头拼接焊缝存在大量裂纹。通过材料、制造、焊接质量等方面对该储罐裂纹进行了原因分析。结果表明,焊接质量控制不当使焊接接头形成淬硬组织,同时由于存在大量扩散氢,使焊接接头产生较大的残余应力,最终导致冷裂纹的产生。针对上述问题对该台容器提出了可靠的返修工艺,保障了容器的安全运行。

Analysis and Repair of Cracking of Nitrogen Storage Tank

The large number of cracks in the head butt welds were found when the first comprehensive inspection was ma-de on a company’s nitrogen storage 16MnR tank. The cause of this tank cracking was analyzed from the aspects of material, manufacturing, welding quality and so on. The results showed that hardening microstructure occurred at welding joint due to the improper control of welding quality. At the same time, large residual stress of welded joints was formed due to the existence of hydrogen diffusion, eventually, leading to the cold cracking. In view of the above problems, the repair process for this container was put forward, which can guarantee the safe operation of the container.