Fatigue behaviour analysis of EN8 steel subjected to various heat treatments created for shaft

Steel is a ubiquitous and popular material for engineering applications. The term “fatigue” was used for failure under cyclic or dynamic loading. The reason behind approximately 90 percent of the failure is fatigue. The purpose of this study is to know the different reasons, behaviour, and aspects of fatigue failure for solid shafts. The material selected for this current investigation is EN8 medium carbon steel containing 0.42 % carbon subjected to different heat treatment processes at different temperatures and different treatment times. The microstructure of different heat-treated samples at different temperatures and different processing times were recorded, the mechanical properties were calculated, and fatigue behaviour analysis was done to predict the best fatigue life of steel shafts. The findings revealed that the samples treated at low tempering temperatures (250 °C) for minimum treatment time (one hour) showed the best results in terms of hardness, yield stress, ultimate tensile stress, % of Elongation, and fatigue life. The increment in tempering temperature and treatment time for the medium carbon steel samples showed the results in terms of decreased value of hardness, yield stress, ultimate tensile stress, % of Elongation, and fatigue life.