球罐裂纹的成因分析及预防措施

Analysis and Preventive Measures of Cracks on Spherical Tank

本文以定期检验中发现裂纹的球罐为典型案例,现场进行了荧光磁粉检测、焊接接头残余应力测试和硬度检测,标定了裂纹产生的部位,结合现场检测数据和球罐安装资料,分析了Q370R的碳当量和冷裂纹敏感指数,球壳板焊接和焊后热处理情况。推断出裂纹是由于钢材的淬硬倾向、熔敷金属扩散氢及焊后残余应力共同作用产生的,在役环境下的工作应力导致了焊接裂纹的扩展,提出了相应的预防措施。研究结果对于预防球罐失效、保障其安全质量具有参考价值。

This paper took a typical case of a spherical tank with cracks found during periodic inspection,fluorescent magnetic particle testing,residual stress testing of welded joints and hardness testing were carried out on site,marked the area where the cracks were created,combined with field test data and spherical tank installation information,the carbon equivalent and cold crack sensitivity index of Q370R,spherical shell plate welding and postweld heat treatment were analyzed.It is inferred that the crack is due to the combined effect of the hardening tendency of the steel,diffused hydrogen of the deposited metal and residual stress after welding,working stresses in the inservice environment lead to the expansion of weld cracks,and the corresponding preventive measures are proposed.The results of the study are of reference value for preventing the failure of spherical tanks and ensuring their safety and quality.