大干伸长多丝埋弧焊接工艺研究

Research on Multi-wire SAW with Longer Wire Extension

为了改善多丝埋弧焊大线能量焊接导致的高钢级管线钢焊缝及热影响区金相组织粗化、脆化的问题,采用焊接线能量较低的焊丝大干伸长多丝埋弧焊接工艺进行了焊接试验研究,并与常规四丝埋弧焊工艺进行了对比。经过相同壁厚、材质试板的焊接对比试验发现,焊丝大干伸长多丝埋弧焊工艺比常规四丝埋弧焊工艺焊接线能量降低约20%~25%,显著改善了焊缝及热影响区的低温冲击韧性,两种焊接工艺焊接接头抗拉强度变化不明显。

In order to improve coarsening and embrittlement of metallographic structure in high grade pipeline steel weld and heat affected zone（HAZ） caused by multi-wire submerged-arc welding（SAW） with high heat input, multi-wire SAW technology with longer wire extension and low heat input was studied, and compared with conventional four-wire SAW technology. After contrast welding tests of same wall thickness and material, the weld heat input of multi-wire SAW technology was 20%-25% lower than conventional four-wire SAW technology, low temperature impact toughness of weld and HAZ was improved markedly, and the tensile strength of welding joints with different technologies didn＇t change significantly.