Steel Supplier Evaluation Techniques To Assure Bearing Performance

Abstract

The internal quality of steel is one of the critical factors in the performance of bearings. A multi- national company using steel from many sources around the world must have a detailed and comprehensive program for evaluating steel suppliers to assure ongoing, consistent bearing performance. There are many techniques that have been developed and used over the years such as blue fracture test, microscopic evaluation, oxygen analysis, sophisticated ultrasonic techniques and longer range tests such as fatigue life testing. The control of the process steps in making steel is a critical part of clean steel technology. Timken has developed an ultrasonic technique as well as specific sample preparation requirements to assure the quality of steel will meet the stringent requirements of bearing performance. Recent data from evaluation of many world steel suppliers will be summarized to demonstrate the importance of assuring clean steel. Ultrasonic data from several configurations of samples as well as reduction ratios will demonstrate the importance of a tightly controlled evaluation program.