Influence of local heat treatment on residual stresses in electron beam welding

Abstract

Electron beam welding (EBW), as a high performance welding method, is also subject to requirements of high integrity welds which particularly include residual stresses affecting distortion and fatigue behaviour. In this context multiple beam technique may provide new applications of specific thermal weld treatment. The present work introduces a promising method of local post-heating in a certain distance to the current welding location applying multiple beams for the reduction in residual stresses in EB welded sheet metals. The conducted investigations include finite element analysis (FEA) and stress measurements in the weld seam area. Using a systematic approach within the FEA decisive process parameters are optimised with reference to the achievable reduction in residual stress. All simulation results are validated by experiments applying strain gauges for the stress measurement. Both simulations and experiments revealed a considerable decrease in residual stress achievable by appropriate positioning of additional heat sources combined with the right power input and beam focusing.

Numerical Investigation of Residual Stress in Thick Titanium Alloy Plate Joined with Electron Beam Welding

“…Cowles et al [7] developed a three-dimensional (3D) model to predict the residual stress of EBW on a high-pressure drum rotor and compared the simulated results with an experiment using hole-drilling technology in which the thickness of the component for the 3D model was 8.89 mm. Rosen et al [8] investigated the appropriate parameters of local postheating by applying multiple electron beams using the FEM and experiments with strain gauges in which the thicknesses of welded plates are 2 mm and 3 mm. Lundba¨ck and Runnemalm [9] developed a 3D FE model to predict the distortion and residual stresses in two plates with 6-mm and 7-mm thickness during EBW, and the predictive residual stress was validated by experiment using an incremental holedrilling technique.…”

Reduction of residual stresses in laser beam welds by means of defocused laser beams

“…This practice linked example verifies that this stress mitigating procedure provides a qualified tool for longitudinal stress mitigation in beam welds in complex components and weld geometries by drawing on the recommendations for the process parameter values which were reasoned in Ref. 17. As concerns the temperature the experimental results for the austenitic steel upgrade these recommendations by the fact that the most suitable temperature region to be generated in the heat treated zones depends on the temperature dependent material properties.…”

Basic alloy development of low-transformation-temperature fillers for AISI 410 martensitic stainless steel

“…Kattoura et al [9] reported the extremely prosperous effect of laser peening method on reducing the residual stresses. Also, many other researchers have focused on similar techniques for improving the integrity of structures [10][11][12]. However, the time and price consuming are the well-known problems of these techniques which make them undesirable at the industrial applications, especially in repair welding and welding of large components.…”