基于强化散热的焊后冷源宽度对焊接残余应力的影响

鉴于冷源长度方向尺寸对焊趾位置残余应力峰值的影响不大,本文着重分析冷源宽度方向尺寸对焊后残余应力的影响。本文利用干冰作为焊后冷源介质跟随焊枪同步运动,基于热弹塑性有限元方法,对AH36高强钢薄板随焊激冷的焊接方法进行了模拟。分析了冷源相对于焊缝的宽窄关系对随焊激冷控制残余应力的影响,从而可以对干冰的喷嘴形状设计进行指导,以优化焊后冷源控制应力应变的效果,推进“低应力无变形”焊接技术在船舶领域的发展与应用。结果表明,在焊后施加冷源可以达到降低低应力无变形的效果。其中,在所施加焊后冷源宽度较焊缝宽的情况下,较其他两种宽度冷源控制应力与变形的效果更佳,板中心纵向残余应力可由常规焊的484Mpa减少到375Mpa,减少了109Mpa。

Influence of width of post weld cold source on welding residual stress based on the apprpach of heat dissipation enhancement

Considering that the length and direction of cold source have little influence on the peak value of residual stress in weld toe position, this paper mainly analyzes the influence of the width and dimension of cold source on residual stress after welding. In this paper, dry ice is used as the welding source of cold welding source to follow the synchronous movement of welding torch. Based on the thermo-elastic Plastic Finite Element Method, the welding method of AH36 high strength steel sheet is simulated. Analysis of the cold source relative to the width of the weld with trailing cooling control effect of residual stress, which can guide the dry ice shape of nozzle design, in order to optimize the welding stress and strain of cold source control effect, promote the "low stress no distortion" development and application of welding technology in the field of ship. The results show that the effect of low stress and non deformation can be achieved by applying cold source after welding. Among them, when the width of cold source is wider than the weld width, the effect of stress and deformation is better than the other two kinds of width cold source. The longitudinal residual stress of plate center can be reduced from 484Mpa of conventional welding to 375Mpa, reducing 109Mpa.