轨道客车铝合金厚壁构件激光-MIG复合焊接特性
Welding Characteristics of Laser-MIG Hybrid Welding of Aluminum Alloy Thick-Walled Components for Railway Vehicles
方喜风 1韩晓辉 1杨志斌 2李帅贞 1李刚卿1
作者信息
- 1. 中车青岛四方机车车辆股份有限公司技术工程部,山东青岛 266111
- 2. 大连交通大学材料科学与工程学院,辽宁大连 116028
- 折叠
摘要
为实现轨道客车铝合金厚壁构件高质量焊接,针对20 mm厚6005A-T6铝合金开展激光-MIG复合焊接特性研究,优化坡口尺寸,分析接头组织特征、硬度分布及拉伸性能.结果表明,U形坡口钝边高度8 mm、组对间隙2 mm时,基于优化复合焊接工艺参数采用三层三道方法可以实现高质量焊接.焊缝中心和熔合线附近组织分别为等轴晶和柱状晶,相比填充焊缝区和盖面焊缝区,打底焊缝区的等轴晶尺寸较粗大且柱状晶区宽度最宽;焊缝区和热影响区硬度低于母材区硬度,熔合线附近硬度最低;接头的平均抗拉强度约为191 MPa,达母材抗拉强度的76％,试样断裂在熔合线附近,总体呈现韧脆混合断裂的特征.
Abstract
This study investigates the laser-MIG hybrid welding of 20 mm thick 6005A-T6 aluminum alloy components for rail-way vehicles,aiming to optimize welding parameters and achieve high-quality joints.Through optimization of groove dimen-sions,the use of a U-shaped groove with a root face height of 8 mm and an assembling clearance of 2 mm,coupled with a three-layer and three-pass welding method,yielded optimal results.The microstructures in the weld center and near the fusion line were equiaxed crystal and columnar crystal respectively.Compared with the filling and covering weld zone,the equiaxed crystal size was coarsest and the columnar crystal zone was widest in the backing weld zone.The microhardness of the weld zone and heat affected zone was lower than that of the base metal,and the lowest microhardness was found near the fusion line.Despite this,the average tensile strength of the joints reached 191 MPa,representing 76％of the base metal strength.The samples fractured near the fusion line,and the fracture morphologies generally showed the ductile-brittle mixed fracture features.
关键词
激光技术/激光-MIG复合焊/铝合金/厚板/焊接特性/轨道客车Key words
laser technique/laser-MIG hybrid welding/aluminum alloy/thick plate/welding characteristics/railway vehicles引用本文复制引用
基金项目
中国博士后科学基金(2019M650053)
辽宁省教育厅科学研究经费项目(JDL2020026)
出版年
2024
NETL
NSTL
万方数据