基于微观组织优化的锻造工艺预成形及毛坯形状优化设计

Shape optimization design of the preform and billet of the forging process based on the microstructure optimization

以锻件晶粒尺寸细小均匀为目标,以预成形形状设计为对象,提出了锻造成形过程微观组织优化设计方法,构建了晶粒尺寸、锻件形状子目标函数以及无量纲化的总目标函数,确定了预成形形状作为优化过程的设计变量;给出了优化设计的具体步骤,采用微观遗传算法和有限元模拟方法开发了基于预成形设计的锻造过程微观组织优化程序;并对典型的圆柱体镦粗进行了面向微观组织优化的预成形设计,给出了能够获得具有良好微观组织的镦粗成形预成形模具型腔形状。通过分析不同高径比的初始毛坯形状对微观组织优化目标函数值的影响,给出了较为合理的初始毛坯形状高径比取值范围。

An optimization design method of the microstructure in forging process is proposed. The optimal objective is to obtain the fine and symmetrical grain size. The optimal object is the perform shape. The grain size sub-objective function, the shape sub-objective function and the whole objective function for the multiple objective function optimization are put forward, respectively. The perform shape is used as the optimal design variables. The steps of the optimization design are given. Using the genetic arithmetic and FEM simulation, the software for optimal design method of the microstructure in forging process based on perform design is developed. The perform design of the cylinder upsetting process realizes the optimization of the final microstructure, and the shape of the perform die is given. The reasonable scope of the HID ratio of the initial billet is suggested according to the value of the objective function with the different HID ratio of the initial billets.