Volume 3, Issue 2 (February 2006)
Continued Developments in Easily Carburizable High Speed Steel Alloys
A technical update on how bearing fatigue life in high speed steels (HSS) is enhanced by modifying the carbide distributions and morphologies is presented. A brief review of the laser glazing process as applied to bearings (U.S. Patents 5,861,067 and 5.879,480) will be presented. For wrought M50 steel, this processing resulted in an increase in bearing L10 % fatigue life of approximately 10×. The microstructural enhancements created by this processing will be illustrated. How the knowledge gained from the laser glazing process led to the development of the easily carburizable high speed steel alloys (U.S. Patent 6.702,981) will be discussed. Developments made for these alloys since the last bearing steel symposium in 2001 will be presented. The most notable achievement in the development process is a 20× increase in bearing L10 % fatigue life for the easily carburizable version of M50 as compared to standard M50 HSS. Other data pertinent to these alloys will be presented.