The effect of post weld heat treatment on the creep-fatigue behavior of gas tungsten arc welded 308L stainless steel
The effect of post weld heat treatment on the creep-fatigue behavior of gas tungsten arc welded 308L stainless steel
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DOI：
10.1016/j.msea.2006.03.105
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发表时间：
2006-07
期刊：
影响因子：
6.4
通讯作者：
F. Liu;Y. Hwang;S. Nam
中科院分区：
文献类型：
--
作者：
F. Liu;Y. Hwang;S. Nam
采用308L不锈钢进行钨极气体保护焊(GTA)焊接。用透射电子显微镜观察了焊前和焊后热处理(PWHT)焊件蠕变疲劳试验前后的显微组织和相变。结果表明，高温PWHT处理后，由于位错的重新排列和残余应力的消除，一次循环软化被一次硬化所取代。在蠕变疲劳试验过程中，初生δ铁素体主要转变为Sigma相，残余δ铁素体的数量取决于热处理和蠕变疲劳试验条件。此外，高温热处理有延缓δ铁素体向σ相变的趋势，从而提高了焊件的蠕变疲劳抗力。
Gas tungsten arc (GTA) weld joints were made from 308L stainless steel. The microstructure and phase transformation of the as welded and post weld heat treated (PWHT) weldments before and after creep-fatigue test were examined using transmission electron microscopy (TEM). The results show that the primary cyclic softening is replaced by primary hardening after high temperature PWHT, which is due to the rearrangement of dislocation and the relief of residual stress. The primary δ-ferrite mainly transformed into sigma phase during the creep-fatigue test, and the remaining amount of δ-ferrite depends on the PWHT and creep-fatigue test conditions. Further more, high temperature PWHT shows a tendency to retard the δ-ferrite to σ-phase transformation, which in turn promotes the creep-fatigue resistance of the weldment.