激光辅助活性焊接法

Laser aided activating TIG welding

提出了激光辅助活性焊接的方法,研究了焊接参数对激光熔化处理后TIG焊接熔深、熔宽的影响.首先,使用极小功率激光在氧气保护下熔化焊件表面,使焊缝表面的氧含量增加.然后使用普通的TIG焊接,覆盖激光焊缝,达到增加熔深的目的.利用此方法,不使用活性剂就可以使TIG焊焊接熔深增加约2倍,与A-TIG焊相比没有表面熔渣,表面成形较好.小功率激光处理后焊缝中O元素含量增加,熔池表面张力温度系数由负变正,导致激光辅助活性焊熔深增加.

On the bases of the study for the mechanism of the increasing of A-TIG welding penetration,a new method of activating TIG welding,the laser aided activating TIG welding was proposed.At first,the surface of weld was melt by the mini power laser protected by oxygen.As a result,the oxygen content increases in the weld pool surface.Then the conventional TIG welding was used to cover the weld.The oxygen could change the direction of fluid flow in molten pool,which leads to the weld beads with narrower width and deeper penetration.Without the activating flux,the penetration can be increased by 2 times.There is no slag in the surface of weld and the appearance is good.The oxygen can change the temperature dependence of surface tension gradient from a negative value to a positive value;and cause the significant changes in the weld penetration.Fluid flow could be inward along the surface of the weld pool toward the center and then down.This fluid flow pattern transfers heat to the weld root and produces a relatively deep and narrow weld efficiently.This change is the main cause to increase the penetration.