Pass-by-pass stress evolution in multipass welds

Abstract

In multipass welding, each successive thermal cycle will introduce local melting, solid state phase transformations, grain growth, grain refinement, recrystallisation and recovery, all of which lead to a complicated stress state. Most stress measurements performed on multipass welded components represent the final residual stress state. Information concerning stress evolution on a pass-by-pass basis is difficult to find. In this investigation, six pass welds were made on high strength quenched and tempered steel sections, and depth resolved strain measurements in two orthogonal directions were carried out after each weld pass using energy dispersive synchrotron X-ray diffraction. The residual stresses were calculated using biaxial Hooke's law. A thermalmetallurgical-mechanical welding model was constructed and validated with temperature and pass-by-pass stress measurements, which improves the reliability of the model. Cross-sectional stress distributions are presented after each pass, revealing the weld stress development in multipass welds.

Numerical simulation of a temperature field during multi-beads surface welding

“…In many of them, theoretical (numerical) considerations were subjected to experimental verification. In [7][8][9][10] the calculated temperature field was verified by comparing theoretical and measured (using thermocouples) welding thermal cycles. In [11][12][13][14][15], the calculated and real shapes and sizes of fusion zones were compared.…”

“…Numerous papers have been published since then, in which numerical methods were used for analysis of thermomechanical states of multi-pass welding, a.o. in [7][8][9][10][11][12][13][14][15]. In many of them, theoretical (numerical) considerations were subjected to experimental verification.…”

“…The above publications [4][5][6][7][8][9][10][11][12][13][14][15] present the results of numerical simulations for butt and fillet welded joints. Reed and Bhadeshia [16] first proposed a simple model for rebuilding by use of the welding process.…”

Investigation of the eects of the weld groove shape on the residual stress formation in the butt-welded plates

“…During the last decade, a signi cant progress has been made in the prediction of the residual stresses of di erent welding processes, and several commercial nite element codes can now handle this issue [1]. Gao et al studied pass-by-pass stress evolution in multipass welds using Finite Element (FE) technique [2].…”

Investigation on hot cracking during laser welding by means of experimental and numerical methods

“…Fixed constraints were applied to simulate the clamping condition. An elasto-plastic theory with isotropic hardening was used [22]. Green-Lagrange and second Piola-Kirchhoff theories were assumed in the FE model to calculate strain and stress.…”