The effect of rolling contact loading on the texture of retained austenite in tapered roller bearings

Understanding the effect of rolling contact loading on the microstructure of tapered roller bearings used in the railroad industry is the key to developing bearings for long life applications. The microstructure of these bearings consists of a mixture of tempered martensite and retained austenite. The amount of retained austenite has been the subject of much debate for many years. Retained austenite in steel is a metastable phase that has the ability to transform to martensite under the proper conditions. The transformation to martensite is associated with a volume change that can change critical dimensions and be detrimental to the service life of the bearing. While this area of study has been researched for decades, little is known about the texture of retained austenite and its effect on bearing life. Previous works have measured the texture of the bearing in the as-produced state and after service conditions. This work utilizes these results to develop a model for the texturing of retained austenite in the bearing race during service. Good experimental agreement was obtained between simulations conducted using the Taylor polycrystal plasticity theory and the experimental data.