MODIFIED THERMITE RAIL WELDING PROCEDURE

A modified thermite rail welding procedure was developed in which thermite steel that normally comprises the filler metal of a full fusion thermite rail weld was expelled from between the rail ends while in a liquid or partially solidified state. This expulsion was caused by applying an axial force to the rails to move their ends together. It was believed that the expulsion would alter the solidification microstructure and decrease the number and size of metallurgical discontinuities in the fusion zone by decreasing the volume of filler metal, thus improving the joint's fatigue properties. Modified and standard thermite welds were fabricated and compared using the results of chemical analyses, metallography, hardness tests, and tension tests. The application of force during solidification disrupted the directional patterns of solidification and caused a refinement of pearlite colony size compared with the standard thermite rail weld fusion zone. The modified thermite rail weld had a hardness similar to the standard thermite rail weld and tensile properties superior to standard thermite rail welds. The modified joint's tensile properties were similar to those of electric-flash-butt rail welds.

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/trr/1994/1470/1470-011.pdf
• Record URL:
  https://scholar.google.com/scholar_lookup?title=MODIFIED+THERMITE+RAIL+WELDING+PROCEDURE&author=G.+Fry&author=F.+Lawrence&publication_year=1994
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• Supplemental Notes:
  • This paper appears in Transportation Research Record No. 1470, Railroad Research Issues. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved
• Authors:
  • Fry, Gary T
  • Lawrence, Frederick V
• Publication Date: 1994

Language

• English

Media Info

• Features: Figures; Photos; References; Tables;
• Pagination: p. 93-98
• Monograph Title: Railroad research issues
• Serial:
  • Transportation Research Record
  • Issue Number: 1470
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Chemical analysis; Hardness tests; Metallography; Railroad rails; Railroad tracks; Tension tests; Welding
• Uncontrolled Terms: Modifications
• Old TRIS Terms: Rail welding; Thermite steel
• Subject Areas: Construction; Highways; Railroads;

Filing Info

• Accession Number: 00677731
• Record Type: Publication
• ISBN: 0309061016
• Files: TRIS, TRB
• Created Date: May 22 1995 12:00AM