摘要
在金属构件的热成形过程中,变形温度、应变速率和应变等工艺参数对构件的微观组织影响显著,调控工艺参数获得理想显微组织是提高构件综合力学性能的一种有效手段.本文总结了一种基于热加工性能优化的构件锻造工艺参数设计方法,其大致步骤包括热变形行为表征与流变应力数据扩充、基于扩充流变应力数据的热加工图建立和加工参数窗口识别、基于识别的加工参数窗口优化工艺参数、优化工艺参数应用.综述了描述材料高温流变行为的本构模型,主要包括唯象模型、基于物理机制的本构模型和智能模型;材料热加工图的构建方法,主要包括原子模型和动态材料模型;动态再结晶模型,主要包括位错模型和唯象模型.最后,通过两个具体案例说明了该方法在获得较优热加工性能锻件的可行性.
Abstract
In the hot forming process of metal components,the process parameters such as deformation temperature,strain rate and strain have a significant influence on the microstructure of the components.Controlling the process parameters to obtain the ideal microstructure is an effective means to improve the comprehensive mechanical properties of components.This paper summarizes a design method for the process parameters of forging of components based on the optimization of hot-working properties,the general steps of which include the characterization of hot deformation behavior and the expansion of flow stress data,the establishment of hot-working diagram based on expanded flow stress data and the identification of machining parameter windows,the optimization of process parameters based on identified machining parameter windows,the application of optimized process parameters.This paper summarized the constitutive models describing the high-temperature flow behavior of materials,including phenomenological model,constitutive models based on physical mechanism and intelligent models,the construction method of hot-working diagram of materials,which mainly includes atomic model and dynamic material model,and the dynamic recrystallization model,which mainly includes dislocation model and phenomenological model.Finally,the feasibility of this method in obtaining the forgings with better hot-working properties is illustrated by two specific cases.
维普
万方数据