In this study, double-sided submerged-arc-welded CSEF steel joints were considered for microstructural and mechanical (hardness, ductility and strength) characterisations for four different cases of preheating and PWHT processes. The XRD and EDS analyses were also performed to investigate the phase transformation and chemical composition. Preheating was observed to be an improving factor for ductility and hardness of the welds. Similarly, PWHT enhanced the uniformity in the hardness distribution owing to reduced austenitic grain size in the HAZ as well as equiaxed fine-grained ferrite matrix in the FZ. It was observed that preheating and combined preheating and PWHT increased the ductility of the weld by 16.9% and 56.3%, respectively, from the as-welded case. Furthermore, it was also observed that preheating individually and preheating combined with PWHT reduced the maximum hardness values by 8.2% and 60.2%, respectively.

在这项研究中，考虑了双面埋弧焊CSEF钢制接头在四种不同的预热和PWHT工艺情况下的微观结构和机械（硬度，延展性和强度）表征。还进行了XRD和EDS分析以研究相变和化学组成。观察到预热是改善焊缝延展性和硬度的因素。同样，由于降低了热影响区中的奥氏体晶粒尺寸以及降低了FZ中的等轴细晶粒铁素体基体，PWHT增强了硬度分布的均匀性。观察到，与焊接后的情况相比，预热，预热和PWHT的结合分别使焊缝的延展性提高了16.9％和56.3％。此外，