关于焊接应力变形两个问题的进一步探讨

讨论了焊缝是否存在压缩塑性变形问题和拉达伊D应力应变原理图存在的问题。指出刚刚经历熔化—凝固过程的焊缝不存在压缩塑性变形 ,一直承受拉伸塑伸变形。拉伸塑性变形区的范围要比拉达伊D的原理图上给出的大得多 ,对拉达伊D的原理图进行全面修改 ,提出新的焊接热应力应变原理图。在新原理图中 ,三组曲线分别是升温—降温、压缩—拉伸和拉伸弹性—塑性变形的分界线。将等温线所处的温度明确为熔点 ,它包围的区域为熔池。取消弹性卸载区的提法 ,改为弹性变形区。整个焊接板由弹性变形区、压缩塑性变形区、拉伸塑性变形区和熔池组成。

Further Discussion on Two Problems of Welding Stress and Deformation

In this paper,the problems on compressive plastic deformation in the weld and the principle of welding stress and strain described by D.Ladayi have been discussed.It was pointed out that there is no compressive plastic deformation,but tensile plastic deformation for the weld undergoing melting solidification process.The range of tensile plastic deformation zone is much larger than that indicated by D.Ladayi.The principle diagram put forward by D.Ladayi was modified,and an new principle diagram of welding thermal stress and strain was advanced.In the new diagram,3 curves are heating up cooling down,compressive tensile and tensile elastic deformation tensile plastic deformation respectively.The temperature positioned on the isothermal line was definitely called as melting point,the range surrounded by it is welding melting pool.The concept of elastic unload was chaged into elastic deformation zone.Whole weldment includes practically elastic deformation zone,compressive plastic deformation zone,tensile plastic deformation zone and melting pool.