变极性等离子弧焊在壳体与法兰环焊缝焊接中的应用

Application of variable polarity plasma arc welding in girth welding of shell and flange

分析了铝合金变极性等离子弧穿孔焊工艺的特点,采用ER5356焊丝对厚度为7 mm的防锈铝合金5A06进行穿透型变极性等离子弧焊对接环焊缝的焊接试验,分析焊缝成形质量的影响因素,实现了变极性等离子弧焊在某水下产品中壳体与法兰环焊缝连接的应用,焊接过程分为起弧段、穿孔段、焊接段、搭接段、收孔段、收弧段共6个焊接阶段。利用X射线衍射仪、万能拉伸机对接头的质量及力学性能进行检测,结果表明5A06铝合金壳体与法兰对接环焊缝成形良好,焊缝质量满足GJB 294A-2005《铝及铝合金熔焊》Ⅰ级焊缝要求,接头抗拉强度为301 MPa,达到母材的90.2%,断裂位置处于近熔合线处,接头力学性能良好,满足产品的使用要求。

The technological characteristics of variable polarity plasma arc welding(VPPAW)of aluminum alloy are analyzed.The penetrating variable polarity plasma arc butt girth welding experiment of anti-rust aluminum alloy 5A06 with thickness of 7 mm is carried out by using ER5356 welding wire.The influencing factors of weld forming quality are analyzed,and the application of variable polarity plasma arc welding to shell-flange girth welding in an underwater product is realized.The welding process is divided into six stages:arc-striking,perforating,welding,lapping,hole-closing and arc-extinguish.The quality and mechanical properties of the joint are tested by X-ray diffractometer and universal stretcher.The results show that the girth weld of 5A06 aluminum alloy shell and flange is well formed.The weld quality meets the requirements of grade I weld of GJB 294A-2005"Fusion Welding of Aluminum and Aluminum Alloys".The tensile strength of the joint is 301 MPa,which is 90.2%of the base material.The fracture position is near the bond line.The mechanical properties of the joint are good and meet the requirements of the product.