铝/钢异种材料搅拌摩擦搭接焊接温度场和变形行为  

Temperature field and deformation behavior of friction stir lap welded dissimilar materials of aluminum/steel

作　　者：闫松涛 杨斌 YAN Songtao;YANG Bin(National Center for Materials Service Safety,University of Science and Technology Beijing,Beijing 102206,China;Chongqing Millison Technologies Inc.,Chongqing 401321,China)

机构地区：[1]北京科技大学国家材料服役安全科学中心,北京102206 [2]重庆美利信科技股份有限公司,重庆401321

出　　处：《焊接》2025年第3期59-67,共9页Welding & Joining

摘　　要：【目的】厘清搅拌摩擦搭接焊接过程中温度演化和材料流动行为,有利于解析搅拌摩擦多物理场对焊缝质量的影响。【方法】该研究在ABAQUS环境下,基于耦合的欧拉‒拉格朗日(CEL)模型,建立了准静态、高可靠性、高精度的铝钢异种合金搅拌摩擦搭接焊数值模型,研究了6061铝合金(上)与Q235钢(下)搭接焊过程中接头区域温度场、等效塑性应变场和应力场的演变规律。【结果】结果表明,搅拌针长度对搭接焊接头的温度和变形影响显著。在焊接过程中,接头纵向截面温度和应变均呈自上而下、自中心向两侧逐渐降低的趋势。搅拌针越长,产热和材料的变形越剧烈,从而促进材料流动;此时,材料内应力也会增大。此外,搅拌针的长度对铝合金板材中应力分布影响较小。材料混合后,单位体积内的欧拉体积分数(EVF)云图模拟结果表明,长搅拌针有助于界面处材料的混合,且后退侧材料混合更充分,形成钩状结构。【结论】在长搅拌针作用下,随着搅拌针伸入钢材,钢与铝发生机械咬合,较大的性能差异使得在前进侧和搅拌头的下端容易产生缺陷。因此,搅拌针长度作为影响焊接质量的重要因素,在开展异种材料的搅拌摩擦焊接试验前需要选择合理的搅拌针长度。[Objective]To clarify temperature evolution and material flow behavior of friction stir lap welding process was helpful to analyze influence of friction stir multiple physical fields on weld quality.[Methods]A numerical model with quasi-static,high reliability and high precision accuracy,was established for simulation of friction stir lap welded dissimilar alloys of aluminum and steel based on coupled Eulerian-Lagrangian(CEL)model in ABAQUS environment.Evolution of temperature field,equivalent plastic strain field and stress field in friction stir lap welded joints of 6061 aluminum alloy(top)and Q235 steel(below)were studied.[Results]The results indicated that probe length had significant impacts on temperature and deformation of lap welded joints.In welding process,temperature and strain of welded joints in longitudinal section decreased gradually from top to bottom and from center to both sides.Long probe could increase heat production and material deformation,which promoted material flow process.At this time,internal stress of material would also increase.Moreover,probe length had little effect on stress distribution in aluminum alloy plates.After material mixture,EVF cloud map indicated that long probe facilitated material mixture at the interface,and materials mixed more thoroughly in the retreating side,which accelerated formation of hook like structure.[Conclusion]Under the action of long probe,with the probe inserted into steel,steel and aluminum engaged mechanically,significant difference in mechanical performance made it easy to form defects in the advancing side and the below position of probe.Therefore,as an important factor affecting welding quality,probe length should be selected before conducting friction stir welding tests on dissimilar materials.

关 键 词：耦合的欧拉-拉格朗日模型 搅拌摩擦搭接焊 温度场 缺陷 材料混合 

分 类 号：TG456[金属学及工艺—焊接]