A full-field residual stress estimation scheme for fitness-for-service assessment of pipe girth welds: Part I – Identification of key parameters

Residual Stress Analysis in Girth-welded Ferritic and Austenitic Steel Pipes Using Neutron and X-Ray Diffraction

“…Under suitable conditions, pipe wall bending can occur, leading to compressive axial residual stresses at the weld toe of girth welds, but also to tensile residual stresses at the weld root, which was shown by other authors, see e.g. [2,3], and in previous studies on ferritic-pearlitic and austenitic steel pipes using X-ray diffraction [4][5][6]. In this work, these will be supplemented by neutron diffraction measurements and the results obtained from the two different steels will be compared.…”

“…Experimental and numerical analyses of welding residual stresses hardly ever show that the conservative assumptions made in the IIW recommendations hold. In girth-welded pipes, the pipe geometry and the heat input have been identified as the governing factors for the residual stress development [2,3], apart from material parameters. Under suitable conditions, pipe wall bending can occur, leading to compressive axial residual stresses at the weld toe of girth welds, but also to tensile residual stresses at the weld root, which was shown by other authors, see e.g.…”

Prediction of residual stresses in girth welded pipes using an artificial neural network approach

“…austenitic stainless steel girth welds, mainly considering the pipe geometry and welding heat input as the critical input parameters [12], [13] and [14]. In the present work, an artificial neural network (ANN) model has been developed which is trained using historical residual stress measurements to predict through-wall residual stress profiles along the weld-centre line of austenitic stainless steel pipes.…”

A full-field residual stress estimation scheme for fitness-for-service assessment of pipe girth welds: Part II – A shell theory based implementation

“…As a sequel to Part I [1], this paper presents a shell theory based formulation for generalizing key findings reported in Part I so that through-thickness residual stress profile can be estimated not only within weld region, but also at any position away from the weld region until residual stresses completely vanish. This paper starts with a two-part shell model in which the first part represents weld region and second part represents the rest of the component section.…”

“…In addition to weld region (e.g., weld centerline and weld toe locations) as discussed in Part I [1], needs often arise for describing residual stress distributions away from weld region, where residual stresses can be significant when a through-thickness axial residual stress distribution exhibits a "global bending" type as illustrated by Dong [2][3]. As recently discussed by Dong et al [4], there exists little guidance in current structural integrity assessment procedures [5][6][7] for estimating through-thickness residual stress profile as a function of distance away from weld region.…”