Operational damage to the structure and failure of the KAMAZ truck spring in the temperature–load conditions of the North

Resumo

Forecasting of the residual life of machine and structure elements requires consideration of the changes of the metal condition until it achieves its critical states. The failure of the KAMAZ truck spring during the cold operation period under the climatic and natural conditions of the North was studied taking the metal degradation in the zones of different loading into account. The structural damage was estimated using the microhardness and porosity parameters. The physical mechanisms that change the microhardness and the formation of the pore system in the spring steel were analyzed. It is shown that a deviation of the value of the metal microhardness from the normal distribution law is observed in the zone of development of a fatigue crack in the spring. Satisfactory resistance of the spring material to the development of a failure is revealed under the considered temperature–load conditions. A materials-engineering analysis confirmed the role of the road conditions as a more significant destructive factor during the working of the spring in the permafrost zone compared to the factor of the low temperatures.