IN690高温合金管材挤压变形动态再结晶模拟

Numerical simulation of dynamic recrystallization of IN690 super alloy during tube extrusion

对IN690高温合金管材挤压变形过程中的动态再结晶进行了模拟研究,获得了不同挤压工艺条件下动态再结晶与平均晶粒尺寸的变化规律。研究表明:在挤压速度和挤压比一定的条件下,随着挤压温度的升高,完全动态再结晶区域变大,平均晶粒尺寸增大;在挤压速度和挤压温度一定的条件下,随着挤压比的增大,完全动态再结晶区域变大,平均晶粒尺寸减小;管材壁厚方向上由内壁向外平均晶粒尺寸呈现先增大后减小的规律;平均晶粒尺寸的模拟值与实验值的相对误差小于12%。

Dynamic recrystallization( DRC) microstructure evolution of IN690 super alloy during tube extrusion process had been studied by numerical simulation. The evolution law of dynamic recrystallization and the average grain size at different extrusion parameters were obtained. The results show that when extrusion speed and extrusion ratio is constant,with the increasing of extrusion temperature,fully dynamic recrystallization region is expanded,while the average grain size increases. When extrusion speed and extrusion temperature is constant,with the increasing of extrusion ratio,fully dynamic recrystallization region is expanded,while the average grain size decreases.From the inside to outside of the tube wall thickness direction,the average grain size increases firstly and then decreases. The relative error of grain size between simulation results and experimental results is less than 12%.