Fatigue and crack growth behavior of Inconel 718-AL6XN dissimilar welds
Fatigue and crack growth behavior of Inconel 718-AL6XN dissimilar welds
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DOI：
10.1016/j.msea.2018.12.087
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发表时间：
2019-02-04
期刊：
影响因子：
6.4
通讯作者：
Jaramillo, D.
中科院分区：
文献类型：
--
作者：
Cortes, R.;Rodriguez, N. K.;Jaramillo, D.
研究了EFtNiFeCr-2填料与Inconel 718和AL6XN合金气体钨极电弧焊接的疲劳和裂纹扩展行为。对比了IN718和AL6XN整体合金和IN718-AL6XN异种焊接接头的Wohler曲线。尽管维氏显微硬度曲线显示IN718母材的热影响区存在软区，但疲劳裂纹在靠近AL6XN的熔合区形核并沿焊缝扩展。尽管在AL6XN/焊缝界面处存在未混合区，但焊接接头和AL6XN母材表现出相似的高周疲劳行为。疲劳裂纹扩展试验结果表明，由于存在Laves和NbC等脆性二次相，焊缝金属的扩展速率最高。实验数据得到的疲劳裂纹扩展速率与断口表面条纹间距离的测量值比较，两者非常接近。
The fatigue and crack growth behavior of Inconel 718 and AL6XN alloys joined with an EFtNiFeCr-2 filler by the gas tungsten arc welding process was evaluated. A comparison between Wohler curves for the monolithic IN718 and AL6XN alloys and the IN718-AL6XN dissimilar welded joint were obtained. Although Vickers microhardness profiles revealed the presence of a soft region in the heat affected zone of the IN718 base material, the fatigue crack nucleated at the fusion zone near to the AL6XN and propagated across the weld bead. The welded joint and the AL6XN base material presented a similar high cycle fatigue behavior despite the presence of an unmixed zone at the AL6XN/weld metal interface. The results of the fatigue crack growth test indicated that the weld metal has the highest growing rate owing to the presence of brittle secondary phases such as Laves and NbC. The fatigue crack growth rates obtained from experimental data were compared with measurements of the distance between striations on the fracture surfaces, both were very close.