Abstract Narrow gap welds have been increasingly used in pressure vessels and pipe components due to their unique advantages. A recent comprehensive investigation into residual stress distributions in narrow gap is presented in this paper, covering component wall thickness from 1” (25.4 mm) to 10” (254 mm), component radius to wall thickness ratio from 2 to 100, and linear welding heat input from low (300 J/mm) to high (18,000 J/mm). By means of a residual stress decomposition technique, two key parameters that govern through-thickness residual stress distributions in terms of their membrane and bending content have been identified. One is component radius to wall thickness ratio (r/t) and the other is a characteristic heat input density ( Q ˆ ) having a unit of J/mm3. With these two parameters, a unified functional form for representing through-thickness residual stress profile in narrow gap welds is proposed for supporting defect assessment. Its adequacy for estimating residual stress distribution trends is further confirmed by comparing with thermomechanical finite element residual stress analyses for a number of selected narrow gap weld cases.

中文翻译：

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窄槽环焊缝中的残余应力和适用性评估的应用

摘要 窄间隙焊缝以其独特的优势在压力容器和管道部件中得到越来越多的应用。本文介绍了最近对窄间隙残余应力分布的综合研究，涵盖了从 1 英寸（25.4 毫米）到 10 英寸（254 毫米）的部件壁厚、从 2 到 100 的部件半径与壁厚比以及线性焊接从低 (300 J/mm) 到高 (18,000 J/mm) 的热输入。通过残余应力分解技术，已经确定了控制全厚度残余应力分布的两个关键参数，即薄膜和弯曲含量。一个是组件半径与壁厚之比 (r/t)，另一个是特征热输入密度 (Q ˆ )，单位为 J/mm3。有了这两个参数，提出了一种用于表示窄间隙焊缝全厚度残余应力分布的统一函数形式，以支持缺陷评估。通过与一些选定的窄间隙焊缝情况的热机械有限元残余应力分析进行比较，进一步证实了它对估计残余应力分布趋势的充分性。