15SiMn钢奥氏体等温相变的元胞自动机模拟

建立了15SiMn钢奥氏体一铁素体相变的二维元胞自动机介观模型.模拟结果显示,对于某一给定温度,铁索体的长大速度在相变过程中逐渐降低.当生长速度接近0时,奥氏体相中相界面处平衡碳的质量分数为0.523 95%.此外,模拟结果还显示,由于奥氏体晶界上的碳原子扩散和奥氏体-铁素体相界面移动都较奥氏体晶内更快,所以奥氏体晶界上铁素体晶粒形貌为椭圆形.

Cellular Automaton Modeling of Isothermal Transformation of Austenite in a 15SiMn Steel

A two-dimensional meso-scale cellular au-tomaton model was developed to simulate the transfor-mation of austenite to ferrite in 15SiMn steel. The simulated results show that, at a given isothermal temperature, the average growth rate of ferrite is de-creased gradually during the austenite transformation. With the ferrite growth rate decreasing to zero, the carbon concentration in the austenite at the interface reaches equilibrium carbon concentration ot 0.52395%. In addition, the morphology of ferrite grains on austenite boundary exhibits ellipsoidal, which is attributed to carbon diffusion and movement of austenite-ferrite interface higher in the austenite boundaries than that in austenite interiors.