Abstract Rehabilitation of welded structures has gained increasing attention lately. This paper aims at investigating the efficiency of Tungsten Inert Gas (TIG)-remelting and TIG-remelting followed by High Frequency Mechanical Impact treatment (TIG-HFMI) in fatigue life extension. Fatigue tests were carried out on as-welded and cracked specimens after treatment. The lives of the treated specimens increased remarkably by the two methods (TIG and TIG-HFMI). Many of the treated specimens ran-out after 10 million cycles of loading and failed at the clamping location when tested at a higher stress range. The improvement in compressive residual stresses, hardness values and weld toe radii were the reasons behind the life extension. These factors were used for fatigue life estimation in as-welded and TIG-treated specimens using the base metal S N curve. Moreover, the test results together with results from previous tests in the literature demonstrated that these methods can be useful for crack retrofitting as for new structures.

中文翻译：

---

通过钨惰性气体重熔和高频机械冲击修复焊接结构的疲劳裂纹

摘要 近年来，焊接结构的修复受到越来越多的关注。本文旨在研究钨惰性气体 (TIG) 重熔和 TIG 重熔后高频机械冲击处理 (TIG-HFMI) 在延长疲劳寿命方面的效率。对处理后的焊态和裂纹试样进行疲劳试验。两种方法（TIG 和 TIG-HPMI）处理后试样的寿命显着增加。许多处理过的试样在 1000 万次加载循环后跑出，并在更高的应力范围内测试时在夹紧位置失败。压缩残余应力、硬度值和焊趾半径的改善是延长寿命的原因。这些因素用于使用母材 SN 曲线估算焊接态和 TIG 处理试样的疲劳寿命。