基于新型回火焊道的焊接残余应力评价

Evaluation of weld-pass process on eliminating weld residual stress

某扩建工程为降低III类容器改建中的焊接残余应力,尝试采用新型回火焊道工艺.针对焊接工艺优化与评价问题,采用Q345钢焊接试板,对3种工艺(普通焊接及2种新型回火焊接)、2种模式(平板及T形板)的6块试板(600 mm×300 mm×30 mm)应用X射线法进行全面的测试与评价.结果表明,采用回火焊接工艺的1号及3号T形板在焊缝处的应力比普通焊接工艺试件分别降低46%及36%,回火焊接工艺使纵向应力降低,横向应力成为第一主应力;A面的残余应力高于B面25%以上.实际工程中为降低残余应力可去除焊缝余高.

In order to reduce the welding residual stress,researchers adopted tempering weld-pass treatment for the improvement of the class III vessels in an expansion project.Due to the optimization and evaluation of welding process,the researchers conducted a comprehensive test and evaluation by X-ray method on six Q345 steel welding test plates(600 mm×300 mm×30 mm),with three kinds of processes(welding and two kinds of new tempering welding treatment) and 2 patterns(flat butt and T-joint welded plate) and considering the weld metal polished(side B) while the other side(side A) not.The results showed that the welding residual stress in 1 and 3 T-plate decreased by 46% and 36% respectively than which is not with tempering welding treatment.Tempering weld-pass treatment reduced the longitudinal stress(LS),and the transverse stress(TS) became the first principal stress.The residual stress of A-side was 25% higher than that of B-side.To reduce the residual stress,the weld metal can be removed in practical engineering applications.