基于数值模拟的冷拉钢丝表面精度Ra的优化

Optimization of surface accuracy Ra for the cold drawn steel wire based on numerical simulation

为研究拉拔参数对冷拉钢丝表面精度Ra的影响,采用有限元软件MARC建立了钢丝表面微观形态的分析模型,对钢丝拉拔过程进行了模拟仿真,利用正交试验设计法研究了主要拉拔参数(拉拔速度v、过渡圆弧半径R、模具定径带长度L、模具入模角α、摩擦系数μ)对钢丝成形表面精度Ra的影响,并对模拟结果进行了极差分析和方差分析.结果表明:冷拉钢丝在一定断面缩减率的条件下Ra最佳的拉拔参数组合为v=30 mm/s、R=1 mm、L=3 mm、α=11°、μ=0.4);各因素对Ra的影响程度次序为B(R)>C(L)>E(μ)>A(v)>D(α);随v和L的增大Ra先减少后增大,α、R及μ对Ra的影响并无明显规律.在此基础上对优化方案进行模拟仿真,发现钢丝表面粗糙度有了显著改善,这表明正交试验设计对冷拉钢丝表面精度优化的有效性.

To analyze the influence of drawing process parameters on surface accuracy Ra of cold drawn wire, the software MARC was used to establish the steel surface microcosmic structure analysis model and the wire cold drawing simulation was also. carried out. The influences of the main drawing parameters （ drawing velocity v, transition arc radius R, die sizing zone length L, the die semi-angle a, friction coefficientμ） on wire surface accuracy Ra were investigated by using the mathematical orthogonal experimental design method. The optimal drawing parameters （v = 30 mm/s, R = 1 mm, L = 3 mm, a = 11 ° ,μ = 0. 4 ） under certain reduction of section ar- ea and the effect on analysis index Ra were obtained according to the simulation results by range analysis and variance analysis. The effect degree of significance for Ra is B（R） 〉 C（L） 〉 E（μ） 〉 A（v） 〉 D（a）. Mean- while, the Ra firstly decreases and then increases with the increasing of v and L. while there does not exist obvi- ous influential law between Ra and R,μ, a. Furthermore, the optimal drawing parameters were simulated, and the surface finish Ra got an obvious improvement which confirmed the effectiveness of the orthogonal design in drawn wire surface accuracy optimization.