Rolling/sliding contact fatigue life prediction of sintered and hardened steels

Among the several competing mass production methods, powder metallurgy (PM) techniques give much contribution as a means of saving material and energy. It also delivers the material with good fatigue properties that are good substitute for the conventional materials. Application of PM parts is getting wider in many areas such as automotive parts, agricultural equipment, business machine, electrical and electronics, hardware and industrial applications, etc. Many structural machine components made of PM route like gears and bearings experiences rolling–sliding contact fatigue conditions (RSCF). Contact fatigue is a type of failure commonly found in the surface of bearings, gears etc., and this type of failures decide the useful life of these structural parts. Presence of friction between the bodies normally encountered in service, many influence the contact fatigue behavior. The use of new materials and in particular sintered materials requires a thorough understanding of contact fatigue behavior for better product design and development. RSCF on sintered and hardened of 7 gm/cc density (FLC 4608-110HT, Fe–Ni PM steel) were carried out in a specially designed test rig for different contact parameters such as contact stress and slide to roll ratio. Twin-disc type rolling/sliding experimental set-up has been developed in laboratory to simulate the sliding and rolling between two rollers. Contact stress distribution and RSCF life prediction models suitable for sintered and hardened steel were also developed. The predicted life was compared with the experimental RSCF life for sintered and hardened steel.