25MN电极压机压制过程模拟及模具的结构优化

目的 针对25MN电极压机压制自耗电极过程中模具发生断裂失效这一问题，利用数值模拟的方法分析模具产生断裂失效的原因，并对模具结构进行改进。方法 首先建立了压机模具的三维模型，利用有限元分析软件Deform-3D对自耗电极的压制过程进行了数值模拟。其次通过对压制出的电极块密度、电极块表面等效应力以及电极块表面温度等进行综合分析，找到模具结构的薄弱位置，并对其进行了结构优化改进。最后利用有限元分析软件ANSYS Workbench及Deform-3D对改进前后的模具分别进行了约束模态对比分析及自耗电极压制过程的对比分析。结果 在工作过程中，电极压机的顶模比底模更易产生断裂失效，其薄弱位置分布在左右两侧的尖角部位。优化后顶模的各阶模态变形量均小于优化前的各阶模态变形量;优化后的顶模压制出的电极块相对密度更大，由原来的0.89增大为1，电极块的致密性更好;电极块表面温度降低，顶模发生塑性变形的概率减小;顶模尖角内侧受电极块的反作用力减小，发生断裂失效的风险降低。结论 上述研究结果验证了本文对顶模结构优化的合理性，并为电极压机模具的结构优化提供了一定的理论参考。

Process Simulation of 25MN Electrode Press and Structure Optimization of Die

The work aims to analyze the reason of fracture failure of the die by numerical simulation, and improve the structure of the die to solve problem of die fracture failure in 25MN electrode press pressing consumable electrodes. In this work, a 3D model of the press die was first established, and the finite element analysis software Deform-3D was used to numerically simulate the pressing process of the consumable electrode. Through comprehensive analysis on the density of the pressed electrode block, the equivalent stress on the surface of the electrode block and the surface temperature of the electrode block, the weak position of the mold structure was found and the structure was optimized and improved. Finally, the finite element analysis software ANSYS Workbench and Deform-3D were used to carry out comparative analysis on the constrained mode of the die before and after the improvement and comparative analysis of the consumable electrode pressing process. The simulation results showed that the top die of electrode press was more prone to fracture failure than the bottom die in the working process, and its weak position was distributed in the sharp corners of the left and right sides. The modal deformation of the top die after optimization was smaller than that before optimization. The relative density of electrode block pressed with the optimized top die was higher, which increased from 0.89 to 1, and the density of the electrode block was better. When the surface temperature of electrode block decreased, the probability of plastic deformation of the top die decreased. The reaction force of the electrode block inside the tip corner of the top die was reduced and the risk of fracture failure was also reduced. The above research results verify the rationality of the structure optimization of the top die in this paper, and provide a theoretical reference for the structure optimization of the electrode press die.