防止厚壁异种钢管道焊缝根部产生收缩沟的方法

Methods of preventing shrink ditch in weld root of thick-wall dissimilar steel pipes

分析了在核电站核岛安装工程中,对于管道壁厚大于14mm的超低碳不锈钢管(Z2CN18.10)和碳钢管(P280GH)组成的异种钢对接接头,焊接后在碳钢侧热影响区焊缝根部产生收缩沟的原因。根据获得的数据分析说明了收缩沟现象主要是由于碳钢侧热影响区碳迁移和焊接应力的共同作用造成的,并通过焊接试验验证了收缩沟原因分析的正确性,同时总结了合适的焊接工艺和操作方法,有效解决了收缩沟这一问题。

This paper analyzes the reasons of shrink ditch in weld root in carbon steel side heat-affected zone in the nuclear power island erection,in which the pipe wall thick is greater than the 14 mm made of ultra-low-carbon stainless steel pipe（Z2CN18.10） and carbon steel pipe（P28GH）,composed dissimilar steel butt joints.According to the data,this paper analysizes that shrink ditch phenomenon is mainly due to combined actions with carbon on transfer of the HAZ of steel carbon side and welding stress,with welding testing, the reasons analysis is correct ,and summarizes the suitable welding process and operating methods ,solves effectively the shrink ditch defects.