大轴径比工件辊锻过程宽展变形研究

Research on wide stretching deformation of large shaft-to-diameter ratio workpiece during roll forging process

针对现有的塔尔诺夫斯基宽展模型在设计辊锻模具过程中无法获得重剑等大轴径比锻件的辊锻宽展系数的问题,开展了大轴径比锻件平锻实验研究,解析了平锻实验宽展数据,并补充了塔尔诺夫斯基宽展模型。基于扩展后的模型设计了某型重剑剑条14道次的辊锻拔长模具,建立了剑条辊锻拔长过程的塑性有限元模型,模拟了第5道次剑身辊锻拔长过程,并采用应变分析和应力分析得到了辊锻变形区的金属流动规律。结果显示:宽展主要来源于锻件高度方向的压缩变形区,有限元模型预测的宽展量与平锻实验得到的等效宽展量吻合较好。该研究成果可用于指导大轴径比锻件辊锻模具设计及辊锻工艺优化。

For the problem that the existing Tarnovsky wide stretching model cannot obtain the roll forging wide stretching coefficient of forgings with large shaft-to-diameter ratio such as epee swords during the design process of roll forging mold,an experimental study on flat forging of forgings with large shaft-to-diameter ratio was carried out,the experimental wide stretching data of flat forging was analyzed,and the the Tarnovsky wide stretching model was supplemented.Based on the suppled model,a 14-pass roll forging stretching mold for a certain type of epee sward bar was designed,the plastic finite element model of the roll forging stretching process of sword bar was estab-lished,and the roll forging stretching process of the 5th pass of sword body was simulated.Finally,the metal flow law in the roll forging deformation zone was obtained by strain analysis and stress analysis.The results show that the wide stretching mainly comes from the com-pression deformation zone in the height direction of forgings,and the wide stretching predicted by the finite element model is in good agreement with the equivalent wide stretching obtained in the flat forging experiment.Thus,the research results can be used to guide the design of roll forging molds and the optimization of roll forging process for forgings with large shaft-to-diameter ratio.