基于类等势场的粉末高温合金盘件预成形设计

Pre-forming design of P/M superalloy disc based on equipotential field

根据能量最小原理和最小阻力原理,利用塑性变形过程中坯料的流动规律与静电场等势线分布类似这一特性,提出一种能够进行预成形设计的新方法——类等势场法,并采用该方法对粉末高温合金盘件进行预成形设计,从中优选出6组预成形形状,利用MSC/Super Form商用有限元软件对上述预制坯的等温成形过程进行了数值模拟,得到了6组粉末高温合金盘件在预锻到终锻过程中的应力率参数和应变率梯度.通过对盘件轮毂、辐板和轮缘3个部位6个典型单元体应力率参数g的比较与分析,以及整体盘件应变率梯度的比较,并参考预锻变形量和终锻变形量,认为选择3号预锻模为最佳方案.

On the basis of the minimum energy theory and the minimum resistance pressure theory, a new method for the design of die shapes in forging process has been proposed as the equi-potential field method, and it was adopted to design the pre-forming forging shape of a new-type P/M superalloy disc. The isothermal forging of P/M superalloy disc was simulated by MSC/Superform software with six obtained typical die shapes. The stress ratio parameter and strain rate gradient distribution of them in the process of pre-forging and finishforging were obtained. The relationship curves of stress ratio parameter and deformation degree were established to be used for selecting the best pre-forming forging shape of superalloy disc. Through comparing the stress ratio parameter, the strain rate gradient distribution and the deformation degree, an optimal design for pre-forging die is recommended.