Experimental and Computer Simulation of Grain Growth in HSLA-100/80 Steels During Welding and Cladding

Austenite grain size distributions in the heat-affected zone (HAZ) of weld and clad HSLA-100 and HSLA-80 steels is observed to increase to a peak grain size 150-200 μm away from the fusion line and then decrease with increasing distance from the fusion line. This represents a grain growth anomaly indicative of strong grain boundary liquation pinning. A Monte Carlo grain growth algorithm, modified to take grain boundary liquation pinning into account, is used to simulate grain growth in the HAZ of a microalloy-free heat of HSLA-100. For the Monte Carlo simulation, a liquation temperature of 100 K below the equilibrium solidus temperature was found to reproduce the grain size distribution found in the arc weld HAZ of the steel.