On the Development of Computer Model for the Economic Analysis of Alternate Tie/Fastener Configuration
Date
1991-12
Authors
Zarembski, Allan M.
Palese, J. W.
Martens, J. H.
Journal Title
Journal ISSN
Volume Title
Publisher
American Railway Engineering Association
Abstract
The recent trend in rail manufacturing has focused on the development and manufacture of "clean steel", which has been defined as steel with a significantly reduced level of inclusions. This trend has been in response to the increasingly severe loading environment that today's rail is subject to, together with an increasing emphasis on reduction in rail failures (defects), and a corresponding increase in the rail's service life, particularly under conditions where fatigue is the dominant mode of service failure. As a direct result of this, steel manufacturers have been upgrading their steel making process to eliminate inclusions and impurities that could result in rail defects. This trend has been accentuated by recent indications of a relationship between increased rail cleanliness and a reduction in the development of fatigue defects in the rail [1,2]. However, this relationship appears to be quite complex, depending on the definition of rail cleanliness (using such techniques as the ASTM-volume fraction of oxide inclusions or the total length of oxide stringers [3]), the type of inclusions, as well as other metallurgical properties such as rail hardness [2]. However, data showing a direct correlation between changes ("improvements") in manufacturing process, aimed at increasing the level of cleanliness, and reduction in the level of rail fatigue defects in service, has been extremely limited. The purpose of this report is to present two such sets of data relating the in service performance of rail, made by one rail manufacturer, Bethlehem Steel Corporation, to changes in the rail steel making process. These two sets of data represent actual fatigue defect histories on two major u.s. railroads under a broad mix of traffic. The objective of this activity was to analyze the performance and behavior of standard carbon rail and fully heat treated rail produced by Bethlehem Steel Corp. and to define the relationships between performance, specifically development of fatigue defects, and manufacturing process and practice as defined by the time period of rail manufacture.
Description
Keywords
Rail Manufacturing
Citation
Zarembski, A. M., Palese, J. W., & Martens, J. H., “ The Effect of Improved Rail Manufacturing Process on Rail Fatigue Life”, American Railway Engineering Association, Bulletin 733, Volume 92, December 1991.