Residual stress and distortion control using low transformation temperature effect and welding heat field for high- and low-alloy steels using electron beam welding

Residual stress and distortion are ongoing issues in the welding of high- and low-alloy steels, frequently resulting in dimensional inaccuracies, reduced structural performance, and increased susceptibility to cracking. This study investigates a novel approach for reducing these effects through electron beam welding (EBW), utilizing the low transformation temperature (LTT) effect in combination with meticulous regulation of the welding heat field. The LTT effect involves the strategic selection of materials that experience martensitic transformation at reduced temperatures during cooling, producing advantageous compressive stresses that mitigate the tensile residual stresses commonly developed in the weld zone and heat affected zone.In this work, EBW was conducted on both high-alloy (EN1.4301) and low-alloy (S235) steels using LTT-compatible parameters to promote the formation of transformation-induced compressive stresses. The process was carefully controlled to optimize heat input, cooling rates, and weld geometry to achieve the LTT effect effectively. Energy-dispersive x-ray spectroscopy (EDS), distortion measurement, dilatometry analysis and residual stress measurements were used to assess the impact of the LTT effect and heat field on residual stress control and distortion reduction. This study establishes an effective, material- and process-driven approach to minimizing residual stress and distortion in EBW. By integrating the LTT effects along with the heat field, it provides a robust pathway for enhancing weld quality, fatigue life and dimensional stability.