PHYSICAL AND MATHEMATICAL MODEL OF ABRASIVE WEAR OF SORMAITE SURFACES AFTER VACUUM HEAT TREATMENT

The working bodies of tillage machinery are subject to abrasive wear. A fundamentally new microscopic model for assessing abrasive wear for multilayer systems is proposed using the example of L53 steel with sormite surfacing after vacuum annealing. Unlike traditional macroscopic models, the proposed approach takes into account microstructural features: hardness gradients, diffusion processes, phase transformations, damage accumulation, and destruction energy at nano- and microscales. A mathematical model of the hardness profile in the interface zone is constructed based on Fick's second law. It was found that vacuum annealing leads to significant strengthening of the deposited layer: the hardness increases from 4.24 to 8.58 GPa due to diffusion alloying and precipitation of finely dispersed carbides. The energy criterion of wear, in which the volume of removed material is defined as the ratio of the work of destruction to the specific energy of surface destruction, depending on the local hardness, has been developed. The accumulation of damage under cyclic loading was taken into account, which allows predicting wear under conditions of repeated contact with abrasive particles. A detailed calculation example demonstrating a decrease in total wear by 41.7% after heat treatment is given. The theory is accompanied by the derivation of calculation formulas, numerical verification. The research results allow not only to explain the mechanisms of increasing wear resistance, but also to optimize the surfacing and annealing modes for industrial applications. The developed model is applicable not only to the L53 steel - sormite system, but also to other multilayer materials with gradient properties. The work has both fundamental and applied significance in the field of tribology, materials science and engineering physics, etc.