SERVICE LIFE ESTIMATION METHOD FOR BEARING STEEL

摘要

PROBLEM TO BE SOLVED: To provide a method for accurately estimating the service life of bearing steels in a short time and to provide high-reliability bearing steels having a long service life determined by using its service life estimation formula as an index. SOLUTION: A preliminary life estimation formula is derived by executing a multiple linear regression analysis by selecting plural life dominant parameter candidates from contents of impurities contained in the bearing steels and the size of a nonmetal intermediate to use all the life dominant parameter candidates as explanation variables and by using an objective variable as an actual service life in a life test. The explanation variable maximizing a contribution rate subjected to double adjustment in terms of the degree of freedom is obtained from the life dominant parameter candidates, a final life estimation formula is obtained by executing the multiple linear regression analysis again by using the explanation variable, and the service life of the life test using the bearing steels is estimated by the final life estimation formula.