ACOUSTIC EMISSION MONITORING OF SHOP AND FIELD WELDS OF RAIL

A short program was conducted utilizing state-of-the-art acoustic emission instrumentation to monitor both thermite cast welding and electric flash butt welding of rail. The primary objective of the program was to investigate the applicability of acoustic emission techniques for establishing the quality of the weld. Welds on continuous rail strings were monitored during electric flash butt welding, weld cool-down and weld anneal. The specimen welds were fabircated to represent a variety of good and poor conditions. Piped rail sections, for example, were joined to good rail and electrode burns were purposely made, as were good welds. The acoustic emission data, both location and number have been correlated with mechanical properties established by physical tests of the welds. Fractographs of the rail sections are shown. The acoustic emission data gathered during the weld anneal cycle shows a tentative relationship with the strength of the weld. A total of seven welds were monitored where acoustic emission data was obtained. Thermite cast welding, as used in the field joining of rail, was also monitored with the same acoustic emission instruments. Variations in the weld procedure were used to produce good and poor quality welds during this portion of the program. The acoustic emission data was obtained both during the pour and subsequent weld cool-down. A total of three welds were monitored. The instruments, techniques and test results present a clear description of the ease of performing acoustic emission monitoring. Due to the limited number of thermite welds monitored, the data by itself is inconclusive, however, analysis of the weld sections provides some rationale which tends to support the creditability of the technique. The data obtained during the electric flash butt welding shows a good to excellent possiblity of usefulness as a quality control monitor.

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 71 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00098082
  • Record Type: Publication
  • Source Agency: Association of American Railroads
  • Report/Paper Numbers: R-162
  • Files: TRIS
  • Created Date: Aug 13 1976 12:00AM