轴承钢球毛坯热斜轧成形过程数值模拟

Numerical Simulation on Hot Helical Rolling Forming Process of blank for Bearing Steel Balls

轴承钢球毛坯螺旋孔型斜轧工艺设计和变形行为较为复杂,传统的解析计算和物理试验方法不能有效揭示其轧制变形机理。探讨总结了钢球毛坯热斜轧成形主要建模技术与方法,基于SIMUFACT有限元软件平台首次建立了钢球毛坯热斜轧成形三维热力耦合有限元仿真模型。基于有限元模拟结果详细分析了轴承钢球毛坯热斜轧成形过程等效应变、应力、温度和轧制力能参数的分布与演变规律,证明钢球毛坯斜轧心部疏松或空洞缺陷的产生是由其在轧制过程承受的循环交变切应力、较高水平的横向拉应力和由多向拉应力引起的较大负静水压应力(正的平均应力)共同作用的结果。

Due to the complexity of process design and deformation behaviors during the hot helical rolling of bland for bearing steel balls, the traditional methods of analytical calculation and physical experiments are difficult to investigate its rolling deformation mechanisms. The main modeling techniques and methods for hot helical rolling forming of steel balls are discussed and summarized,and a 3D coupled thermo -mechanical finite element simulation model is firstly developed based on SIMUFACT finite element software platform. Based on finite element simulation results, the distribution and evolution rules of equivalent strain,stress, temperature and rolling force and power parameters during hot helical rolling forming process of bland for bearing steel balls are analyzed in detail. It is proved that the central loosen or cavity defects during helical rolling of blank for steel ball is the combination result of circular - alternating shear stress, higher level transverse tensile stress and larger negative hydrostatic pressure （ positive mean stress） caused by multi - directional tensile stresses.