400 Commonwealth Drive, Warrendale, PA 15096-0001 U.S.A. Tel: (724) 776-4841 Fax: (724) 776-5760 SAE TECHNICAL PAPER SERIES 1999-01-0289 Development of Special Heat Treatment to Improve the Bearing Fatigue Life Hyounsoo Park, Seung Cheal Jung and Tae Won Lim Hyundai Motor Company International Congress and Exposition Detroit, Michigan March 1-4, 1999Downloaded from SAE International by University of Auckland, Sunday, August 05, 2018The appearance of this ISSN code at the bottom of this page indicates SAE’s consent that copies of the paper may be made for personal or internal use of specific clients. This consent is given on the condition,however, that the copier pay a $7.00 per article copy fee through the Copyright Clearance Center, Inc.Operations Center, 222 Rosewood Drive, Danvers, MA 01923 for copying beyond that permitted by Sec-tions 107 or 108 of the U.S. Copyright Law. This consent does not extend to other kinds of copying such ascopying for general distribution, for advertising or promotional purposes, for creating new collective works,or for resale. SAE routinely stocks printed papers for a period of three years following date of publication. Direct your orders to SAE Customer Sales and Satisfaction Department. Quantity reprint rates can be obtained from the Customer Sales and Satisfaction Department.T o request permission to reprint a technical paper or permission to use copyrighted SAE publications in other works, contact the SAE Publications Group. No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior wr itten permission of the publisher. ISSN 0148-7191 Copyright 1999 Society of Automotive Engineers, Inc. Positions and opinions advanced in this paper are those of the author(s) and not necessarily those of SAE. The author is solely responsible for the content of the paper. A process is available by which discussions will be printed with the paper if it is published in SAE T ransactions. For permission to publish this paper in full or in part, contact the SAE Publications Group. Persons wishing to submit papers to be considered for presentation or publication through SAE should send the manuscript or a 3 00 word abstract of a proposed manuscript to: Secretary, Engineering Meetings Board, SAE. Printed in USAAll SAE papers, standards, and selected books are abstracted and indexed in the Global Mobility DatabaseDownloaded from SAE International by University of Auckland, Sunday, August 05, 20181 1999-01-0289 Development of Special Heat Treatment to Improve the Bearing Fatigue Life Hyounsoo Park, Seung Cheal Jung and Tae Won Lim Hyundai Motor Company Copyright © 1999 Society of Automotive Engineers, Inc. ABSTRACT A new technique of heat treatment is developed for the bearings of automotive transmission and chassis to max-imize their service life under contaminated and severeenvironments. This study demonstrates an improvementof the microstructure of bearing steels by applying spe-cial heat treatments. The microstructure is developed byoptimizing various heat treating parameters (tempera-ture, cycle time and gas atmosphere, etc.) as well as bymodifying the quenching processes (double quenchingand press quenching). We obtained a desirable micro-structure of dense and fine martensite with optimum lev-els of retained austenite and compressive residual stresson the subsurface. The size and distribution of carbidesand grains are found to be very fine and homogeneous.The endurance test results show that the specimens withnew treatment have an excellent fatigue life comparedwith the conventional bearing samples. INTRODUCTION High performance rolling bearings are more widelydemanded by the automakers to meet the stringent dura-bility requirements as well as the extended warranty stan-dards. Many researches have been carried out toimprove the service life of rolling bearings for the automo-bile transmissions and the wheel hubs where the bear-ings are us