Monte Carlo Simulation Of Grain Growth In HAZ Of X70 Pipeline Steel

In this paper, Monte Carlo (MC) technique was used to research the austenite grain growth in heat-affected zone (HAZ) of X70 pipeline steel. We have developed the two dimensions non-isothermal MC simulation system, and applied it to simulate the austenite grain growth in the HAZ of X70 pipeline steel. Some factors influencing the grain growth were studied in detail. The MC simulation of grain growth can provide not only grain growth kinetics but also detailed information on grain morphology evolution. Furthermore, MC technique can easily simulate the "thermal pin"phenomenon caused by steep temperature gradient in HAZ. The experimental data based (EBD) model was used to establish the relation between Monte Carlo steps (tMCS) and real time (t) in our simulation. We obtained the parameters of the index of grain growth and activate energy by regression analysis. Through MC simulation test, the relation of average grain size and Monte Carlo steps was established and the parameters of MC model were work out by the method of regression analysis. In this paper, a 2D non-isothermal integrate MC simulation system was developed by C++ Builder, which is a Microsoft Windows computer program. Provided with the temperature field data and material properties, the program can simulate the evolution of grain structure. We apply the system to simulate grain growth in the HAZ of X70 pipeline steel with two different heat cycle. Our research indicates it is successful to simulate grain growth in HAZ by the technique of Monte Carlo.