IN690合金在热压缩过程中的再结晶行为

Recrystallization Behavior of the IN690 Alloy during Hot Compression

摘要:

采用热挤压工艺制备了新型高温IN690合金。采用Gleeble-3500热模拟试验机对IN690合金进行了等轴压缩试验，研究了不同温度、应变速率和变形量对IN690合金动态再结晶(DRX)的影响。采用金相显微镜和电子背散射衍射(EBSD)对IN690合金热变形前后的金相组织、晶粒取向、晶界分布和晶粒取向差进行了系统分析。试验得到的真应力-真应变曲线表明，随着温度的降低或应变速率的增加，IN690合金的流动应力增大。IN690合金变形过程中的软化机制主要是动态回复(DRV)和DRX;随着真应变的增加或应变速率的降低，大角度晶界所占比例增加，这是由于在大的真应变或低应变速率下的DRX形核所致。

Abstract:

A novel high-temperature IN690 alloy was prepared via a hot extrusion process. The Gleeble-3500 thermal simulation test machine was used to perform isometric compression tests to study the effects of different temperatures, strain rates, and deformations on the dynamic recrystallization (DRX) of IN690 alloy. Using metallographic microscopy and electron backscatter diffraction (EBSD), the metallographic structure, grain orientation, grain boundary distribution and grain orientation difference of the IN690 alloy before and after thermal deformation were systematically analyzed. The true stress-true strain curve obtained using the test showed that as the temperature decreased or strain rate increased, the IN690 alloy flow stress increased. The major softening mechanisms during the IN690 alloy deformation were the dynamic recovery (DRV) and DRX; The proportions of high-angle grain boundary increased with an increase in the true strain or a decrease in the strain rate due to the the DRX nucleation for a large true strain or low strain rate.