ANALYSIS OF THE CAUSES OF WEAR ON WORKING SURFACES OF CRANKSHAFT JOURNALS

The paper presents a metal research analysis of crankshaft working surfaces, which is a critical element of the internal combustion engine. The study is aimed at identifying microstructural features, defects and patterns of surface wear under operational loads. The relevance of the study is due to the need to predict the service life of shafts and prevent emergency failures due to fatigue failure and intensive wear. The study objective is to find out formation patterns of the structure and properties of surface layers in areas of maximum contact and bending loads (main and rod journals, fillets, mounting surfaces), as well as to identify mechanisms of material degradation under operating conditions. The key mechanisms of material degradation are identified: fatigue microcracks, adhesive and abrasive wear, and local zones of plastic deformation. To achieve this objective, a set of methods was used: determination of the material chemical composition, determination of hardness on journal fragments, determination of the microstructure of samples. Criteria for estimating the residual life of the shaft based on metallographic features are proposed. The results of the study make it possible to optimize the operation and repair of crankshafts, increasing the reliability and durability of engines. The results can also be used in the design, manufacture and repair of crankshafts to improve engine reliability.