大型球罐裂纹分析及修复要点

Crack analysis and repair of large spherical tank

球罐是十分重要的压力容器,广泛地应用在石油化工行业,针对Q370R钢制液氨球罐,采用科学的方法确定了裂纹产生的原因。不严格执行正确的焊接工艺,造成焊接接头硬度高、残余应力大,产生了氢致裂纹,在介质作用下,引发了大量应力腐蚀裂纹。并给出了以硬度标准的返修判据和焊接操作要点,不仅能够保证返修质量,还能够防止产生新裂纹。

The spherical tank is one kind of very important pressure vessels,and it is widely applied in the petrochemical industry. The scientific methods were used to find the cause of cracks for liquid ammonia spherical tanks of Q370 R steel. The correct welding process was not strictly performed,which results in the high hardness and large residual stress of the welded joints,and leads to the hydrogen-induced cracks.Under the action of the medium,a large number of stress corrosion cracks are initiated. The criteria of repairing by the hardness standard and the points of welding operation were determined,which can not only guarantee the quality of the repairing work,but also prevent the occurrence of new cracks.