GH4169合金楔横轧微观组织演变及动态再结晶机制

采用金相显微镜和电子背散射衍射(EBSD)技术分析了楔横轧制备的GH4169合金轧件的微观组织演变和动态再结晶机制；利用数值分析方法获得了楔横轧过程中等效应变、应变速率和温度的相互关系和变化规律,并探讨对楔横轧GH4169合金动态再结晶的影响。结果表明,楔横轧的变形特点是导致GH4169合金组织均匀和动态再结晶机制不同的主要原因,较大的断面收缩率有利于组织均匀化；轧件表面以非连续动态再结晶机制为主,而心部以连续动态再结晶机制为主。

Microstructure evolution and dynamic recrystallization mechanism of GH4169 alloy during cross wedge rolling

The microstructure evolution and dynamic recrystallization mechanism of GH4169 alloy rolled by cross wedge rolling were characterized by means of metallographic microscope and electron backscatter diffraction (EBSD). The effects of equivalent strain, strain rate and temperature on the dynamic recrystallization of GH4169 alloy during cross wedge rolling were investigated by numerical analysis. The results reveal that the shaping characteristics of cross wedge rolling are the main reasons that induce the homogeneous microstructure and different dynamic recrystallization mechanism of GH4169 alloy. Larger reduction of area is beneficial to improve the microstructure homogenization. The non-continuous dynamic recrystallization mechanism is the main form on the surface of the rolled piece, while the core is dominated by continuous dynamic recrystallization mechanism.