随焊干冰激冷冷源尺寸对焊接残余应力影响的有限元分析  

FEM analysis about effect of cooling source size during welding with dry ice on welding residual stress

作　　者：杨建国[1] 谢浩[1] 闫德俊 贺艳明[1] 钟美达 罗玖强 陈忠前 

机构地区：[1]浙江工业大学化工机械设计研究所,杭州310032 [2]中船黄埔文冲船舶有限公司,广州510715

出　　处：《焊接学报》2017年第2期14-18,共5页Transactions of The China Welding Institution

基　　金：中国博士后科学基金资助项目(2016M590821);国防基础科研计划资助项目(A0720133002);黄埔区重大专项资助项目(201518)

摘　　要：文中利用米粒状干冰颗粒作为冷却介质进行随焊激冷,通过将干冰颗粒与压缩空气混合,借助喷枪从喷嘴直接喷射于试板上,干冰颗粒与试件接触瞬间升华带走大量热量,实现局部快速冷却.基于热弹塑性有限元方法,对1561铝合金随焊激冷焊接的方法进行了模拟,分析不同长度和宽度的矩形冷源对随焊激冷控制残余应力的影响,从而对干冰喷嘴出口形状设计进行指导,以优化随焊激冷控制焊接应力与变形的效果.结果表明,最佳矩形冷源的长宽为40 mm×25 mm,板中心纵向残余拉应力由162 MPa降低为零,板两端纵向残余压应力由常规焊接的59.3 MPa减小到20.4 MPa,减小大约65.6%.Dry ice particles are used as cooling media during welding with trailing intense cooling and sprayed from nozzle after they are mixed with compressed air. After dry ice particles contact with the sheet,they sublimate instantaneously while much heat is taken away,then the local area is cooled.Based on thermal elastic-plastic FEM( finite element method),the technology of 1561 aluminum welding with trailing intense cooling was simulated. After analyzing the effect of rectangular cooling source of different lengths and widths,the optimum rectangular cooling source was then achieved. Thus the design of the nozzle exit shape was guided to optimize the effect of welding with trailing intense cooling on stress and deformation. In this thesis,the optimum length and width are 40 mm × 25 mm,the longitudinal residual tensile stress at the center of the plate decreases from 162 MPa to zero,and compressive stress on both sides from 59. 3 MPa to 20. 4 MPa,about 65. 6%.

关 键 词：随焊激冷 干冰 冷源 温度场 残余应力 

分 类 号：TG404[金属学及工艺—焊接]