ABSTRACT Creep crack growth is known to be the dominant failure mechanism in high-temperature components. Particularly in welded structures operating at elevated temperatures, cracks are often found to initiate and propagate in the vicinity of the weld region which can eventually penetrate into the base material after a long period of operation. In this study, creep crack growth tests have been performed on specimens extracted from an ex-service 316 H welded component to examine the crack initiation and growth behaviour in near-weld regions. The results show that the cracking behaviour of the base metal in near-weld specimens is similar to the as-received 316 H data set, suggesting that the material inhomogeneity would not influence the crack propagation behaviour in service-exposed components. Moreover, the test results show that the crack initiation and growth behaviour of the HAZ specimens can be estimated in much shorter time scales by performing tests on pre-compressed material.

中文翻译：

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316H 型钢退役部件的近焊缝蠕变裂纹扩展行为

摘要 蠕变裂纹扩展是高温部件的主要失效机制。特别是在高温下运行的焊接结构中，经常发现裂纹在焊接区域附近开始并扩展，在长时间运行后最终会渗透到母材中。在这项研究中，对从退役 316 H 焊接部件中提取的试样进行了蠕变裂纹扩展测试，以检查近焊区的裂纹萌生和扩展行为。结果表明，近焊缝试样中母材的开裂行为与接收到的 316 H 数据集相似，表明材料的不均匀性不会影响暴露在役部件中的裂纹扩展行为。而且，