【摘要】 本文用对滚式接触疲劳试验机,测试了四种不同渗碳层深度试件的表面剥落过程,提出了剥落的形成模型,通过对剥落断口的宏观及微观分析,详细阐述了剥落的形成机理。关于剥落裂纹生核的控制应力,本文首次将最大剪应力τ_max等效转换为对称循环变应力τ_d,通过τ_d与平行或垂直于表面的平面内剪应力τ_yz在接触应力场中变化的对比分析,对不同层深的剥落提出了相应的计算准则。更多还原

【Abstract】 Surface spalling process of four specimens with different case carburizing depths was observed on a steel-roller contact fatigue testing machine. A model is thus offered to describe the spalling formation. Macro and micro analyses are made for discussing the mechanism of spalling in detail. In respect to the control stress for spalling crack nucleation, the maximum shearing stress τmax is transformed equivalently into the symmetrical alternating stress τtd, then the calculations of spallings respective to different depths of carburized layer are given by way of the variation analysis of τd in contact stress field by comparison with τyz.更多还原