Residual stress studies on arc welding joints of naval steel (DMR-249A)

Residual stress measurements were performed on DMR-249A steel weld joints fabricated by shielded metal arc welding (SMAW) and activated flux gas tungsten arc welding (A-GTAW) by X-ray diffraction (XRD) and ultrasonic methods. The residual stress values were found to vary significantly across the weld joints. The residual stress build up was observed to be maximum adjacent to the fusion boundary. The variations in residual stress values and micro hardness were observed to be comparable. The residual stress developed in double sided A-GTAW joint were marginally higher in comparison to five pass SMAW joint due to phase transformation associated with high heat input per welding pass for A-GTAW process. Considering benefits of high productivity and savings of labour and cost associated with A-GTAW compared to SMAW process, the minor variation in residual stress build up of A-GTAW joint can be neglected to develop A-GTAW as qualified alternative welding technique for DMR-249A steel.