RAIL ANALYSIS. VOLUME 4: METALLURGICAL EXAMINATION OF RAILS WITH SERVICE-DEVELOPED DEFECTS
A metallurgical analysis was made of 33 carbon-steel rail samples selected from service, 31 of which had service-developed defects. The program was formulated to attempt to establish the metallurgical characteristics that promoted the defects and to establish possible interrelationships among these characteristics, the in-location service stresses, and the defects. This work was performed by U.S. Steel Research under contract with the Ad Hoc Committee on Rail Research, which is comprised of representatives of the American Railway Engineering Association (AREA), the Association of American Railroads (AAR), and the American Iron and Steel Institute (AISI) Committee on Railroad Materials. The present report describes chemical analyses, hardness and tension tests, and the results of wear, deformation, metallographic, and fratographic analyses. A companion report describes the results of Charpy V-notch impact tests, fracture-toughness tests, and fatigue tests. The results of this investigation showed that (1) all the service-developed defects in the rail samples examined were fatigue cracks and (2) all these fatigue cracks initiated at sharp internal notches such as inclusions. A correlation between the metallurgical properties of the rail samples and defect formation could not be made. Overall, it is reasonable to conclude that the service lives of the rails investigated would have been longer if the inclusions responsible for crack initiation had not been present. However, it should be noted that most of these rails had service lives lasting 16 years (500 million gross tons or 455 million metric tonnes), with one sample lasting 22 years (755 MGT or 685 MMT). Furthermore, the service stresses, although unknown, were apparently severe, as evidenced in the deformation of the rail heads.
- Work performed as part of AISI-AREA-AAR Rail Research Program.
United States Steel Corporation125 Jamison Lane
Monroeville, PA United States 15146
- Sonon, D E
- Pellegrino, J V
- Wandrisco, J M
- Publication Date: 1978-3
- Features: Appendices; Figures; References; Tables;
- Pagination: 69 p.
- TRT Terms: Cracking; Defects; Metallography; Metallurgy; Rail (Railroads); Rail steel; Service life; Tests
- Uncontrolled Terms: Observations
- Old TRIS Terms: Rail steel metallurgy
- Subject Areas: Design; Railroads;
- Accession Number: 00183707
- Record Type: Publication
- Source Agency: United States Steel Corporation
- Report/Paper Numbers: R-300 Res Rpt.
- Files: TRIS
- Created Date: Dec 3 1978 12:00AM