The effects of cold work produced by peening processes in residual stress relaxation under elevated temperatures were investigated. Two types of peening processes namely shot peening and laser peening were used to generate different amount of cold work and residual stresses in the study. Characterisation of residual stress induced by cold working were carried out using X-ray diffraction coupled with electrochemical polishing method to measure the variation of residual stress with depth. Residual stresses in shot peened samples were observed to relax more rapidly than that of laser peened ones when subjected to thermal exposure. The data collected from the experimental investigation was then used to build a correlation function to model the effects of cold work on residual stress relaxation. A parameter describing cold work’s contribution to stress relaxation is introduced into the well-known Zener-Wert-Avrami (ZWA) model. The model was validated against experimental measurements and showed good agreement in both shot peened and laser peened samples.

研究了喷丸工艺产生的冷作对高温下残余应力松弛的影响。研究中使用了两种喷丸工艺，即喷丸和激光喷丸，以产生不同数量的冷作和残余应力。利用X射线衍射结合电化学抛光方法对冷加工引起的残余应力进行表征，以测量残余应力随深度的变化。当经受热暴露时，观察到喷丸处理后样品中的残余应力比激光喷丸处理后的残余应力释放得更快。然后将从实验研究中收集的数据用于建立相关函数，以模拟冷作对残余应力松弛的影响。众所周知的Zener-Wert-Avrami（ZWA）模型引入了描述冷作对应力松弛的贡献的参数。该模型针对实验测量进行了验证，并且在喷丸和激光喷丸样品中均显示出良好的一致性。