【摘要】 推导了轴承钢球的热传导方程,采用球贝塞尔函数给出了热处理过程中钢球瞬态温度分布的解答,应用弹性力学热应力理论得出了热处理过程中钢球径向和切向应力公式,并以半径50 mm的大型轴承钢球为例,对钢球应力分布进行了分析。热处理过程中钢球的表面温度变化剧烈;靠近钢球中心位置为三向拉应力,并且同时达到最大值,开裂容易从中心部位开始发生。靠近钢球表面位置处于二向应力状态,径向应力为0 Pa,切向应力为压应力并达到最大值,导致钢球在锻造过程中产生的表面裂纹扩大,并导致钢球开裂。细化钢球中间部位晶粒,减少在锻造过程中钢球上的裂纹,放缓钢球的加热速度能减少热处理过程中钢球的开裂。更多还原

【Abstract】 The heat conduction equation of the steel ball was deduced.Using the spherical bessel function,the transient temperature of steel ball was calculated.Tangential and radial stress formula was deduced by the theory of thermoelasticity.The stress distribution of steel ball which radius is 50 mm was analyzed.In the heat treament process,the temperature change is large.The three dimensional tensile stress which result in the crack of the ball is the maxium in the center.The surface of the steel ball is the two dimensional stress state that the radial stress equals zero,and the tangential compressive stress is the maxium.The two dimensional stress results the extension of the ball’s crack until the ball is damaged.Refining the grain of the steel ball’s center,reducing the crack in the forge process,and slow down the speed of heating of steel ball in the heat treatment process can decrease the crack.更多还原