AerMet100超高强钢在热加工过程中的动态再结晶模型研究

Dynamic recrystallization models of AerMet100 ultrahigh-strength steel during thermo-mechanical processing

摘要:

为了准确预测AerMet100超高强钢在热加工过程中的微观组织演变，通过系列等温热压缩试验分析了合金在温度为800~1040℃、应变速率为0.01~10s-1、变形量为15~60%的热变形行为，并建立了动态再结晶(DRX)体积分数和晶粒尺寸的DRX模型。通过计算获得了AerMet100钢本构模型中的Zener-Hollomon参数，用于建立DRX模型。通过建立的DRX模型定量预测了热变形参数对合金微观组织演变的影响，结合微观组织观察发现，高温低应变速率和较大的变形程度有利于DRX充分发生，使组织细化和均匀化。模型预测结果与实验结果吻合较好，验证了所建立的DRX模型的准确性。结果表明，建立的DRX模型可以定量预测AerMet100钢在不同变形参数下进行热加工时的微观组织演变规律。

Abstract:

In order to accurately predict the microstructure evolution during thermo-mechanical processing of AerMet100 ultrahigh-strength steel, the dynamic recrystallization (DRX) models including DRX volume fraction and DRX grain size were established by conducting a series of isothermal hot compression tests. The hot deformation behavior of the alloy in a wide range of temperatures from 800 ?C to 1040 ?C, strain rates from 0.01 s-1 to 10 s-1 and deformation degree from 15% to 60% were analyzed. The Zener-Hollomon parameter in the constitutive model for the AerMet100 steel was obtained to establish DRX models. The effects of deformation parameters on the microstructural evolution were quantitatively predicted through the established DRX models. The microstructure observations showed that higher temperature, lower strain rate and larger deformation degree were beneficial to obtaining the homogenization and refinement of the microstructure due to the occurrence of DRX. The good agreement between the prediction and the experiment validated the accuracy of the established DRX models. And the results indicated that the DRX models could be used to quantitatively predict the microstructure evolution of AerMet100 steel components during thermo-mechanical processing at different hot deformation conditions.