基于数值模拟的某直升机动环模锻成形工艺研究

Research on Die Forging Process of a Helicopter Moving Ring Based on Numerical Simulation

采用数值模拟技术研究了某直升机动环模锻成形速度场、温度场、应力应变场的分布规律及变化,预测模锻件的成形效果及成形载荷。研究结果表明,锻件成形初始阶段,预制坯料与模具的接触面积较小,金属流动阻力较小,接触部分温度迅速下降且发生塑性变形,其它部位变形较小,坯料主体等效应力分布为30~60MPa。随着模压进行,预制坯料与模具的接触面积增大,金属填充受到的阻力急剧增加,金属径向流动速度与纵向填充速度增大;塑性变形产生热量导致坯料温度下降较少;坯料整体的等效应变略增加,锻件主体等效应力增至60~90MPa。锻件成形效果较好,温度、等效应力分布较均匀,未出现穿流现象。动环模锻件成形最大载荷为27288t。

The numerical simulation technology is used to study the distribution and variation of velocity field,temperature field,stress field and strain field in the die forging process of a helicopter's moving ring,and the forming performance and load of die forging are predicted.The research results show that at the beginning of the molding process,the contact area between prefabricated blank and die is small,the metal flow resistance is low;the temperature of the contact part decreases rapidly and the plastic deformation occurs in this area,while the deformation at other parts is small,and the equivalent stress distribution in most parts of the blank is 30-60MPa.With the die forging proceeding,the contact area between prefabricated blank and die increases,the resistance of metal filling increases sharply,the radial flow velocity and longitudinal filling velocity of metal increases;the heat generated by plastic deformation leads to less decrease of billet temperature;the equivalent stress of the whole blank increases slightly,and the equivalent stress of forgings in⁃creases to 60-90MPa.The forming performance of the die forgings is good,the distribution of temperature and equivalent stress is rela⁃tively uniform,there is no cross-flow phenomenon in metal flow;the maximum load of moving ring die forgings is 27288t.