keywords CARBON-STEEL COMPUTER-PROGRAM FUSION-BOUNDARY GAS TUNGSTEN ARC MECHANICAL-PROPERTIES METAL WELDS MICROSTRUCTURAL DEVELOPMENT Materials Science Materials Science, Multidisciplinary Metallurgy & Metallurgical Engineering PARENT GRAINS SUBMERGED-ARC WELDS Science & Technology TRANSITION JOINTS Technology dissimilar steel welds epitaxial growth incipient melting solidification microstructure thermokinetic modelling welding