25SiMn钢奥氏体等温相变过程的数值模拟  

Numerical Simulation of Isothermal Transformation of Austenite in 25SiMn Steel

作　　者：王狂飞[1] 莫亚林[1] 夏立军[2] 米国发[1] 傅恒志[1] 

机构地区：[1]河南理工大学材料学院,河南焦作454100 [2]中国科学院金属研究所,辽宁沈阳110016

出　　处：《铸造》2008年第8期798-801,共4页Foundry

基　　金：河南理工大学博士基金资助项目(648232)

摘　　要：建立了25SiMn钢奥氏体-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,铁素体的长大速度在相变过程中逐渐降低,当生长速度接近于0时,奥氏体相中相界面处平衡碳浓度为0.527 74%。此外,模拟结果也显示,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,奥氏体晶界上铁素体晶粒形貌为椭圆形。铁素体相的长大速度与奥氏体-铁素体相界面处的奥氏体相一侧碳原子浓度有关。A two dimensional cellular automaton model was developed to simulate the phase transformation from austenite to ferrite in 25SiMn steel. Results showed that, at a given isothermal temperature, the growth rate of ferrite grain decreases gradually during the austenite-ferrite transformation. As the average ferrite growth rate approaches to zero, the carbon concentration in austenite at the interface reaches the equilibrium carbon concentration of 0.527 74wt. %. In addition, the simulations also showed that both the carbon diffusion and mobility of austenite-ferrite interface at austenite grain boundaries are faster than that inside the austenite grain, and the morphology of ferrite grains at austenite grain boundaries is ellipsoidal. The growth rate of ferrite grain is related to carbon concentration in austenite at austenite-ferrite interface.

关 键 词：25SiMn钢 等温相变 元胞自动机 

分 类 号：TG142.11[一般工业技术—材料科学与工程]