轮毂轴承外圈整体淬火过程的数值模拟

Numerical Simulation on Overall Quenching Process for Outer Rings of Hub Bearings

使用材料性能模拟软件JMat Pro得到GCr15钢的热物理参数,以第1代轮毂轴承外圈为例,建立外圈淬火的温度-组织-应力/应变多场耦合模型,研究轮毂轴承外圈在淬火过程中的温度场、组织场和应力/应变场的演化规律。结果表明:轮毂轴承外圈上不同部位的温度变化有着明显差异,表面冷却速度最快,心部冷却速度最慢,心部与表面的最大温差达280℃;淬火后外圈的最大残余应力主要分布在外壁中部和滚道处;淬火后外圈马氏体的分布较为均匀,含量为92.7%,心部与表面硬度一致;淬火过程使轮毂轴承外圈的内外径均略有膨胀,外圈外壁中部膨胀量比两端部大。

The thermal physical parameters of steel GCrl5 are obtained by using material performance simulation soft- ware JMatPro. Taking outer rings of the first generation hub bearings as examples, the temperature - microstructure - stress/strain multi - field coupled model is established for quenching of outer rings. The evolution rule of temperature field, microstructure field and stress/strain field are studied during quenching. The result show that the temperature va- ries obviously in different parts of outer rings of hub bearings, the surface cooling velocity is the fastest while the core cooling velocity is the slowest, and the maximum temperature difference between surface and core is 280 ℃. The maxi- mum residual stress of outer rings are mainly distributed in the middle of external wall and raceway after quenching. The martensite distribution of outer rings after quenching is relatively homogeneous and the content is 92.7%. The core hardness is in accordance with surface hardness. The bore and outside diameter of outer rings of hub bearings are ex- panded, and the expansion quantity in the middle of external wall of outer rings is bigger than both ends.