Volume 3, Issue 8 (September 2006)
Developing ASTM E 2283: Standard Practice for Extreme Value Analysis of Nonmetallic Inclusions in Steel and Other Microstructural Features
The statistical nature of bearing failures has been studied using Weibull probability statistics for over 50 years. Historically it has been demonstrated that the origin of many bearing failures is the presence of large nondeformable nonmetallic inclusions in the bearing steel. Methods for predicting the presence of large inclusions in bearing steels using extreme value statistics were presented in the late 1980s. Several papers presented in the ASTM A 01.28 Bearing Steel Technology Symposium in 1996 discussed this method of analysis. Unfortunately in these and other investigations, standardized methodologies for performing the analysis were not utilized. This paper discusses how ASTM E 2283 was developed. The results of a recently completed interlaboratory round robin testing program are discussed. The application of the standard to microstructural features other than inclusions will be illustrated.