磨损是农机触土部件失效的主因，我国因触土部件磨损造成的损失年均超过150亿元。由于触土部件作业环境复杂，磨损影响因素多，没有哪种材料能够满足各类磨损条件下的使用要求。因此，揭示应用环境下土壤对触土部件的磨损机制与特性极为必要。课题拟从耕层土壤特性入手，采用图像分析和统计学方法，分析土壤粒度表面分形特性、土壤中磨粒的表面形貌、尺寸、形状及分布规律对触土部件耐磨性的影响机制；分析不同类型土壤硬度随含水量、有机质含量及时间历程的变化规律，借助摩擦学理论建立多种磨粒条件及多个磨损机制协同作用下的随机磨粒磨损模型和应用环境条件下触土部件综合磨损概率表达式，并通过室内和田间试验进行验证和优化。依据概率理论和零件磨损寿命预测模型，建立典型触土部件失效图谱，提出磨损寿命可靠性估算算法。通过模糊优化，寻求触土部件使用寿命与制造成本兼顾的优化值，为触土部件的结构设计、材料选择、表面强化及热处理工艺提供依据。

Abrasion is the main reason for the failure of agricultural soil-engaging components and the annual economic losses caused by abrasion is more than 15 billion Yuan. Due to the complicated working environment and the many factors affecting wear of the soil-engaging components, no material can meet the virous requirements under different conditions. Therefore, it is very necessary to reveal the wear mechanism and characteristics of topsoil in the application environment. Focusing on the analysis of topsoil properties, image analysis and statistical analysis methods are used to analyze the effect of fractal dimension of topsoil, surface topography of gravel and distribution rule on wear mechanism of soil-engaging components. The change law of various soil hardness with water content and organic content is analyzed. Based on the tribology theory, stochastic modeling of abrasive wear under multi-abrasive particles’ coupling and multiple wear mechanisms is developed and probability distribution function of comprehensive wear under the practical application environment is established, and then are validated and optimized by field testing. Probability theory and existing wear life prediction models are applied to develop the failure pattern. Failure criterion and reliability estimation algorithm of wear life are put forward. By fuzzy optimization method, optimal compromise between service life and manufacturing cost is exploited, which can provide the evidence for soil-engaging components design, material selection, surface strengthening and heat treatment procedure.