3000 m^(3)丙烯球形储罐焊缝裂纹原因分析与预防措施

Cause Analysis and Preventive Measures of Weld Crack of 3000 m^(3) Propylene Spherical Storage Tank

在某大型化工企业球罐群定期检验期间,发现一台3000 m^(3)丙烯球罐内外表面存在大量焊缝裂纹,分类统计裂纹出现的位置和类别,分析典型裂纹缺陷形貌。总结出焊接技术水平欠佳、现场热处理未达到规范要求、焊接残余应力是导致球罐开裂的主要原因,并给出了具有针对性的处理建议及预防措施。在球罐制造过程中严格控制球壳板原材料质量和制造质量,把控焊接过程质量和焊后焊缝无损检测质量,在定期检验过程中重点关注上、下级环焊缝,可采用UT+TOFD的方法进行焊缝检测。

During the regular inspection of spherical tanks in a large chemical enterprise,there are a lot of weld cracks on the internal and external surfaces of the 3000 m^(3)propylene spherical tank.The cracks are found classified and counted according to the location and category,and the appearance of typical crack defects are analyzed.The causes of weld cracks are analyzed in depth,and the five major causes of weld cracks on the spherical tank are summarized,The targeted treatment suggestions,precautions for the construction,installation and regular inspection of spherical tanks in the future and preventive measures to avoid weld crack are given.The results show that poor welding technology,on-site heat treatment not meeting the specification requirements,and welding residual stress are the main causes of spherical tank cracking.During the manufacturing process of spherical tank,the quality of raw materials and manufacturing quality of spherical shell plate shall be strictly controlled,and the quality of welding process and non-destructive testing of welds after welding shall be controlled.In the regular inspection process,the upper and lower circumferential welds shall be focused on.The method of UT+TOFD can be used for weld testing.