Submerged-arc welding (SAW) may be considered as a miniature casting and the final microstructure of a weld and a casting are both dendritic, but the differences are much greater than the similarities. The microstructure produced in a weld deposits is very complex and may contain several phases and hence has pronounced effect on the mechanical properties, such as hardness, strength and toughness.
The microstructure of the double sided welds joint is generally non-uniform, being composed of areas of as deposited weld metal (first weld) and areas that have reheated by subsequent pass (second weld). The hardness values (HV1/15) within double sided submerged-arc weld metals are different and depends to the exact positioning of the measurements. The obtained results using LM (Light Microscopy), SEM (Scanning Electron Microscopy) and Vickers hardness testing (HV1/15) are presented in this work and this is an attempt to clarify a correlation between microstructure and hardness gradient within double- sided submerged-arc weld metals from microalloyed steel API grade X60.