限定晶粒取向差的多晶马氏体相变行为的相场法研究

Phase Field Study on Martensitic Transformation in Polycrystals with Limited Grain Orientation

基于Welch-Powell算法限定多晶体取向,采用相场法研究了晶粒取向差对多晶马氏体相变的影响。结果表明:大晶粒较小晶粒马氏体的板条形貌更规则,晶界降低了马氏体的生长速度;晶粒取向角比晶粒尺寸对马氏体相变体积分数的影响更大。马氏体相变初期ω值越大,马氏体生长速度越快,ω=60°时的平衡马氏体体积分数高于其他ω值下的平衡马氏体体积分数,随ω值的增大平衡马氏体体积分数减小。

Based on the Welch-Powell algorithm to limit the polycrystalline orientation,the effect of grain orientation difference on the martensitic transformation(MT)in polycrystals was studied by phase field method.The results showed that the morphology of martensitic laths in large grains was more regular than that in small grains,and the grain boundaries reduced the growth rate of martensites.The effect of grain orientation angle on volume fraction of MT was greater than that of grain size.In the initial stage of MT,the higher theωvalue,the faster the growth rate of martensites.The volume fraction of equilibrium martensites atωangle of 60°was higher than that of equilibrium martensites at others angles,and with the increase inωvalue,the volume fraction of equilibrium martensites decreased.