When heat input is controlled reasonably toe of weld is cleaned thoroughly and molten pool is protected rationally the non-defect surfacing layer with big thickness and area can be acquired .

合理控制堆焊热输入、对 焊道 焊 趾 部位的清理，以及堆焊过程中对熔池采取合理的保护，可获得无缺陷的大厚度、大面积堆焊层。

The distances from the failure planes of a HAZ ( heat affected zone ) to the center and the toe of the weld and the extensions of a HAZ and a RSZ ( reduced strength zone ) are measured .

通过试验得出对接焊缝临界失效面距焊缝中心及 焊缝边缘的距离、焊接热影响区及折算强度区的范围；

Fatigue cracks mainly initiate at the weld toe . The fatigue strengths of welded joints in welded structures are much lower than those of the base metal because there are stress concentrations and tensile residual stresses at weld toes .

原因是焊 趾 部位存在应力集中和 焊接残余拉伸应力，使得接头处的疲劳强度远低于基体金属的疲劳强度。

Weld toe UIT can reduce the residual stress of the toe and the weld .

焊 趾冲击不但使 焊趾表面产生压应力，也降低了 焊缝的残余应力。