IN690高温合金管材挤压过程微观组织模拟

Numerical Simulation of Microstructure Evolution during Tube Extrusion of IN690 Super Alloy

对IN690高温合金管材挤压过程进行了微观组织数值模拟,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试验值的相对误差小于12%。

Microstructure evolution of IN690 superalloy during extrusion tube process was visualized by numerical simulation.The evolution process of dynamic recrystallization（DRC）and the average grain size at different extrusion parameters were presented.The results show that at given extrusion speed and extrusion ratio,with the increase of extrusion temperature,complete dynamic recrystallization region is expanded,and the average grain size is increased too.At fixed extrusion speed and extrusion temperature,with the increase of extrusion ratio,complete dynamic recrystallization region is expanded,while the average grain size is decreased.From the inside to outside of the tube wall thickness direction,the average grain size is increased firstly and then decreased.The relative error of grain size between simulation results and experimental ones was less than 12%.