基于有限元的400 MN大型模锻压力机温度场分析

Temperature Field Analysis of 400 MN Heavy Die Forging Press Based on Finite Element Method

模锻件热传导和辐射会造成钢丝缠绕模锻压机机架和动梁温度升高,使钢丝层蠕变加剧、预应力损失,液压介质性能下降,温度场分析至关重要。运用ABAQUS对400 MN模锻压力机进行稳态和瞬态温度场有限元分析,研究顶出缸、动梁钢丝层、机架钢丝层等部位温度场分布特征。结果表明,模具工作温度300℃时,48 h钢丝层温度不大于75℃,满足设计要求,8.4 h顶出缸油温大于70℃,超出设计允许值。鉴于改善散热条件无法有效降低油温,提出缸底、端部加隔热垫片(A)和模具、上模座间加隔热垫片(B)两种结构改进方案,经模拟验证,方案B效果佳,48 h顶出缸油温低于70℃,满足设计要求。有限元分析结果与温度场测量结果基本吻合验证了模型的合理性,温度场分析为压力机结构设计及锻造工艺制定提供有益参考。

Heat conduction and thermal radiation of workpiece could increase temperature of the steel wire wound frame and the moving beam, which may lead to huge creep deformation, pre-stress loss of steel wire and performance degradation of the hydraulic oil. So it is practically important to analyze the temperature field of the die forging press. Steady and transient temperature field analyses are performed for 400 MN forging press by using ABAQUS to study the temperature field characteristics of the ejection cylinder and steel wires of the moving beam and the frame. The results show that when working temperature of the die is 300℃, wire temperature is below 75℃ after 48 h, while oil temperature is above 70℃ after 8.4 h, the latter exceeds the permit limit. Since the improvement of heat dissipation could not decrease temperature effectively, scheme A in which the heat insulation gaskets are added to the bottom and the top of the cylinder and scheme B in which the insulation gaskets are added between the die and the die holder are proposed. It is verified by the simulation that the latter could decrease oil temperature effectively and meet the design requirements, the oil temperature could keep below 70℃after 48 h. The FEM results agree well with the experimental data, which verifies the validity of the FEM modeling. This work provides beneficial reference for structural design and forging process design.