基于CA法的高温合金IN690管材挤压变形动态再结晶组织演变规律研究

Study on Micro-structure evolution of Dynamic recrystallization during tube extrusion of IN690 super alloy based on Cellular Automata

摘要:

采用元胞自动机(CA)方法对高温合金IN690管材挤压变形过程中动态再结晶组织演变规律进行了数值模拟研究。确定了位错密度模型、回复模型、形核模型、晶粒长大模型等。分析了挤压变形过程中动态再结晶的过程,得到了变形过程中的晶粒形态、分布、取向和尺寸。研究结果表明,在相同挤压比条件下,管壁外部的平均晶粒尺寸小于管壁中部；在管材的相同部位,随着挤压比的增大,平均晶粒尺寸减小。平均晶粒尺寸的数值模拟结果与实验结果的相对误差小于16.6％。

Abstract:

Dynamic recrystallization of IN690 super alloy during tube extrusion had been simulated based on Cellular Automata(CA). It had been determined that model of dislocation density and model of reply and model of nucleation and model of grain growth. It had been obtained that grain morphology and distribution and orientation and size during the process of deformation. The results presented that the grain size of the external wall was smaller than that of the middle under the same extrusion ratio. With the increasing of extrusion ratio, the grain size at the same site of the tube decreased. The relative errors of the grain sizes of simulation and experiment were less than 16.6%.