TC4钛合金锥形环辗轧整圆曲线设计及其影响规律

Design Method of Calibrating Curve and Its Effects on Conical Ring Rolling Process for TC4 Titanium Alloy

TC4钛合金锥形环辗轧过程整圆阶段的芯辊进给速度曲线形式,对成形环件的几何(圆度、壁厚均匀性)、温度与应变分布等具有重要影响作用。针对同一TC4钛合金锥形环件热辗轧过程,提出'上凸形'、'下凹形'、'阶梯形'和'直线形'四种整圆芯辊进给速度曲线(整圆曲线)的设计方法;进而采用基于ABAQUS软件平台的建模仿真方法,模拟揭示四种整圆曲线对成形环件圆度、壁厚均匀性以及温度与应变场的影响规律。结果表明,'上凸形'、'直线形'、'阶梯形'、'下凹形'整圆曲线下,成形环件圆度及壁厚均匀性依次变好;成形环件平均温度依次变低,温度分布均匀性依次变好;平均等效塑性应变依次变大,等效塑性应变分布均匀性依次变差。综合考虑环件圆度、壁厚均匀性以及温度与应变情况,'下凹形'整圆曲线相对更适合于TC4钛合金锥形环辗轧过程。

The feed speed curve of the mandrel at the end stage of the conical ring rolling process for TC4 titanium alloy （calibrating curve） plays an important role in the geometric accuracy, temperature and strain fields of the rolled ring. Design methods for four kinds of calibrating curves which are convex, concave, ladder, and linear forms are proposed. The effect rules of four calibrating curves on roundness, thickness uniformity and temperature and stain fields of the rolled ring are explored through numbers of simulations based on ABAQUS software platform. The results show that, under the convex, linear, ladder and concave calibrating curves, the roundness and thickness uniformity of the rolled ring orderly tend to be better; the temperature distribution of the rolled ring orderly becomes more homogeneous but the temperature average is orderly decreasing; and the equivalent plastic strain distribution orderly becomes more inhomogeneous but the average of equivalent plastic strain is orderly increasing. So the concave calibrating curve is the relatively adequate selection among the above four calibrating curves for the conical ring rolling process for TC4 titanium alloy billets.