X70管線鋼焊接HAZ晶粒長大的MC模擬.pdf

1、華中科技大學(xué)碩士學(xué)位論文X70管線鋼焊接HAZ晶粒長大的MC模擬姓名：沈滿德申請(qǐng)學(xué)位級(jí)別：碩士專業(yè)：材料加工工程指導(dǎo)教師：余圣甫20050428IIAbstract In this paper, Monte Carlo (MC) technique was used to research the austenite grain growth in heat-affected zone (HAZ) of X70 pipeline ste

2、el. 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

3、 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” phenom

4、enon 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 parameter

5、s 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

6、 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 d

7、ata 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