Experimental and numerical investigation of the welding impact on residual stresses of the joint region of ASTM-A36 marine steel

The purpose of this study is to assess how the SMAW, CC-GMAW, and DP-GMAW methods affect longitudinal residual stresses, macrostructural properties, and joint region hardness of ASTM-A36 marine steel. Emerging DP-GMAW technique (dual pulse) is another type of pulse current, and the investigation of the effect of current amplitude as one of the parameters related to this technique at three levels of 10, 30, and 45 A on the hardness variation and longitudinal residual stresses are other aims of this study. According to the results, the DP-GMAW technique reduced the longitudinal residual stresses in the weld metal by 36 % and 29 %, respectively, compared with the SMAW and CC-GMAW processes. Moreover, the lowest amount of longitudinal residual stress occurred at a current amplitude of 30 A. Further benefits of the DP-GMAW technology over other procedures include sizable decreases in the weld bead width and the HAZ width, which suggest a reduction in the heat input under these circumstances. Another benefit of the DP-GMAW approach was an increase in the hardness of the joint region. The DP-GMAW technique's current amplitude of 45 A resulted in the weld metal's and the HAZ's maximum hardness. The weld metal's and the HAZ's hardness ratings were 223 and 220 HV, respectively.