MONTE-CARLO SIMULATION OF GRAIN-BOUNDARY PINNING IN THE WELD HEAT-AFFECTED ZONE

A methodology for obtaining a one-to-one correlation between Monte Car lo (MC) and real parameters of grain size and time is described. Using the methodology, and the MC grain growth algorithm, the grain structu re in the weld heat-affected zone (HAZ) of a 0.5 Mo-Cr-V steel has bee n simulated. The simulations clearly show that the kinetics of grain g rowth can be retarded by the presence of steep temperature gradients i n the weld HAZ. Additional pinning due to the formation of grain bound ary liquid near the solidus temperature has also been simulated. It is shown that in order to accurately predict the observed grain size in the weld HAZ of the 0.5Cr-Mo-V steel, the retardation in growth kineti cs due to temperature gradients as well as liquid pinning should be co nsidered.