大型LNG项目高压厚壁不锈钢管道焊接

High pressure thick-wall stainless steel pipe welding for large LNG projects

采用钨极氩弧焊打底、焊条电弧焊填充、盖面的组合工艺焊接厚壁不锈钢管。从选择焊接材料、确定焊接工艺参数、制定焊接顺序、控制焊缝根部质量及不锈钢管道焊接防污染措施等方面介绍厚壁不锈钢管焊接的关键控制点。详述了焊接施工的要求及厚壁不锈钢管焊接中存在的问题及控制措施。结果表明,采用上述工艺及措施,有效解决了厚壁不锈钢管出现的焊接缺陷,可保证焊缝质量;焊接一次合格率达到了94%以上,证明此焊接工艺的适应性,可以在施工生产中推广运用。

Combined process of backing welding with argon tungsten arc welding and filling welding and covering welding with shielded metal arc welding was carried out on the thick wall stainless steel pipe.Key control points of thick-wall stainless steel pipe were introduced from aspects of selecting welding materials,determining welding parameters,establishing welding sequence,controlling quality of weld root and anti-pollution measures of stainless steel pipe welding.The requirements of welding construction and problems and control measures in welding of thick wall stainless steel pipe were described in detail.The results showed that welding defects of thick-wall stainless steel tube was effectively solved by the above technology and measures to ensure weld quality.The first pass rate of welding was more than 94%,which proved the adaptability of this welding process and it could be popularized in construction and production.