Abstract
In the age of global competition, achieving cent percent reliability for any system is a technical challenge to the engineers and researchers. For any machinery system fatigue properties of its component is one of the most influencing parameter for reliability analysis. In the present paper experimental investigation has been made to study the fatigue life (by applying reversal bending stress) of C-40 steel (used for chain conveyor pin) with different grades of surface finish and hardness. Hardness of specimen has been changed by various hardening methods: like water quenching and oil quenching. Subsequently an extensive micro structural study under Scanning Electron Microscope (SEM) has been carried out for fatigue failed surface. It is observed that there are noticeable differences in the modes of failure for plain, water quenched and oil quenched specimen. Finally a recommendation has been made for better fatigue life of the product.