奥氏体不锈钢管窄间隙焊缝疲劳裂纹扩展研究

为了研究奥氏体不锈钢管焊缝的疲劳裂纹扩展行为，依照ASTM E647标准对窄间隙热丝气保焊焊缝进行了紧凑拉伸试验，预制缺口分别位于焊缝中心线、热影响区、熔合线及母材。对窄间隙热丝气保焊焊缝不同位置处的疲劳裂纹扩展速率进行对比，并将窄间隙热丝气保焊焊缝与常规手工电弧焊焊缝的疲劳裂纹扩展速率进行对比。结果表明，窄间隙焊缝的抗疲劳性能优于常规手工电弧焊焊缝；根据Paris公式，窄间隙焊缝和母材的抗疲劳性能高于热影响区，焊缝具有更高的裂纹扩展门槛值。

Fatigue Crack Growth Studies on Narrow Gap Pipe Welds of Austenitic Stainless Steel Material

In order to study the fatigue crack growth behavior of austenitic stainless steel pipe welds, a compact tensile test was carried out on narrow gap hot wire gas shielded welding welds according to the requirements of ASTM E647 standard. The prefabricated notches were located in weld centre line, heat affected zone, fusion line and the base metal respectively. The fatigue crack growth rates at different positions of narrow gap hot wire gas shielded welding welds were compared, and the fatigue crack growth rate of narrow gap hot wire gas shielded welding weld is compared with that of conventional manual arc welding weld. The results show that the fatigue resistance of narrow gap weld is better than that of conventional manual arc welding weld. According to Paris formula, the fatigue resistance of narrow gap weld and the base metal is higher than that of heat affected zone, and the weld has a higher fatigue crack growth threshold.