Keywords

Rolling Contact Fatigue, Scanning Electron Microscopy (SEM), Vacuum Carburizing

Track

Rolling Element Bearings VI (Session 8I)

Effect of Surface Hardening Technique and Case Depth on Rolling Contact Fatigue Behavior of Alloy Steels 

Surface hardening techniques are widely used to improve the rolling contact fatigue resistance of materials. For example, in marine outboard engines, some surface hardened components include connecting rods, crankshafts, driveshafts, gears, and propeller shafts. This study investigates the rolling contact fatigue resistance of hardened, ground steel shafts made from three different bearing-quality alloy steels (8620, 9310, and 4140), and hardened using different techniques (atmosphere carburizing, vacuum carburizing, and induction hardening) at different case depths. The fatigue life of the shafts is determined using a three ball-on-rod rolling contact fatigue test machine. After testing, the surfaces of the shafts are examined using scanning electron microscopy, and their microstructures are examined using metallographic techniques. The fatigue life is related to microstructural variables that help to explain the performance of the different hardening techniques.

Authors and Company/Institution 

Lechun Xie and Q. Jane Wang, Center for Surface Engineering and Tribology, Northwestern University, Evanston, IL
David Palmer, Marine Propulsion Systems Divison, BRP US, Inc., Sturtevant, WI
Frederick Otto, Midwest Thermal-Vac, Kenosha, WI