超大高径比棒料连续镦粗工艺及材料变形规律

目的研究超大高径比棒料连续镦粗制坯的工艺方法及变形规律。方法通过设计带有一定锥度的可拆卸凸凹模模块对坯料失稳进行约束,通过选择合适的锥度、镦粗次数和锻造速度,避免折叠现象的产生,并研究棒料断面不平整对变形失稳的影响。结果与常规镦粗方法相比,可有效提高镦粗变形的均匀性。结论提出了一种适用于超大高径比棒料连续镦粗的锥形模具结构及其成形工艺方法。

Continuous Upsetting Process and Material Deformation Rule of Large Height-diameter Ratio Bars

The paper aims to study the continuous upsetting process and the material deformation rules of large height-diameter ratio bars. A series of detachable upper punch and lower die modules with a certain taper were designed to constrain the instability of bars. By choosing appropriate taper, upsetting times and forging speed, the folding phenomenon could be avoided effectively. Influences of bar cross section on deformation instability were also studied. Compared with the conventional upsetting method, the forming process and die presented in this paper could improve the uniformity of metal deformation effectively. A conical die structure and forming process suitable for the continuous upsetting of large height-diameter ratio bars is proposed.