双金属复合海底管道环焊缝坡口开发技术

Girth Weld Groove Development Technology of Bimetallic Composite Submarine Pipeline

为解决双金属复合海底管道海上铺设出现的环焊缝未熔合缺陷多、切管返修影响工期的问题,分析缺陷原因,认为焊缝坡口角度是形成未熔合缺陷的主要因素,进行不同角度焊接坡口的对比试验,确定优化后的焊接坡口角度,重新进行焊接工艺评定,并经工程项目验证,此举可使环焊缝未熔合缺陷数量大幅下降,焊接质量提高,保证了施工进度。

During the bimetallic composite submarine pipelines laying process,a lot of unfused defects in the girth welds are found,which lead to the repair of pipe cutting and affect the construction period.It was found that the angle of weld groove is the main factor to form the unfused defect after analyzing the reasons of defects.Comparison tests of welding groove at different angles were carried out to determine the optimized welding groove angle.After re-welding process evaluation and project verification,the number of unfused defects in girth welds was greatly reduced,so as to improve the welding quality and ensures the construction progress.