焊条电弧焊和埋弧焊在大型LNG储罐内罐壁板焊接施工中的应用

摘要

LNG storge tank is core equipment of LNG storage and transportation and its construction technology is complex and strict. The welding technique of tank wall plate with 9％ Ni steel is the key of the construction of LNG storage tanks at low temperature.The welding joint is directly connected to the tank's construction quality, safety and reliability.The paper focuses on applications of SMAW and SAW during the construction of tank wall plate, including the choice of welding materials and parameters, designing welding groove,welding sequence and procedure specification. SM AW is applied to vertical position welding,and SAW is applied to horizontal position of girth welding. Welding procedure qualification is carried out and the properties of joints are measured.The results show that two weld joints are qualified.%大型LNG低温储罐是液化石油天然气储运过程中的核心设备,其建造技术复杂,要求严格.而9%Ni钢内罐壁板的焊接技术是大型LNG低温储罐建设的关键,其焊接接头性能的好坏直接关系到储罐的施工质量与安全可靠性.重点介绍了焊条电弧焊和埋弧自动焊在LNG储罐壁板焊接施工中的应用,包括焊接材料的选择、焊接工艺参数的确定、焊接坡口的设计、焊接施工顺序以及焊接施工的注意事项.焊条电弧焊常用于储罐壁板立焊缝的焊接,埋弧自动焊常用于储罐壁板横焊缝的焊接,并对焊接接头进行了焊接性评定.结果证明,两种焊接方法得到的焊接接头均符合LNG低温储罐的设计要求.