Abstract δ ferrite and residual stress are known to affect the corrosion behavior of AISI 304 stainless steel welds. To improve the corrosion resistance of a weld, shot peening is often carried out. This study aimed to investigate the effect of shot peening time on the residual stress evolution in both δ ferrite and γ austenite in a 304 stainless steel weld. The residual stresses of both δ and γ phases were significantly transformed from tensile to compressive after shot peening, and in addition, their surface residual stress deviations were lowered as the peening time increased. The stress versus depth profiles revealed a distinct plastic zone and an effective peening depth. The full width at half maximum (FWHM) of both phases increased as the peening time increased, but that of δ reached to a near stable value at peening 4 min. The FWHM change might be an index of surface coverage of peening, depending on the alloy phases. The electrochemical testing showed that shot peening effectively reduced the corrosion current intensity (Icorr) of the weld to a lower value than that in welds peened by other processes. Both the grain refinement and compressive stress enhanced the corrosion resistance of the weld.

中文翻译：

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喷丸时间对AISI 304焊缝δ/γ残余应力分布的影响

摘要 δ 铁素体和残余应力会影响 AISI 304 不锈钢焊缝的腐蚀行为。为了提高焊缝的耐腐蚀性，经常进行喷丸处理。本研究旨在研究喷丸时间对 304 不锈钢焊缝中 δ 铁素体和 γ 奥氏体残余应力演变的影响。δ相和γ相的残余应力在喷丸后由拉伸显着转变为压缩，此外，它们的表面残余应力偏差随着喷丸时间的增加而降低。应力与深度曲线显示了明显的塑性区和有效的喷丸深度。两相的半峰全宽 (FWHM) 随着喷丸时间的增加而增加，但 δ 的半高宽在喷丸 4 分钟时达到接近稳定的值。FWHM 变化可能是喷丸表面覆盖率的指标，具体取决于合金相。电化学测试表明，喷丸处理有效地将焊缝的腐蚀电流强度（Icorr）降低到低于其他工艺喷丸处理的焊缝的值。晶粒细化和压应力均提高了焊缝的耐蚀性。