Electroslag Welding (ESW) for High-Performance Steel (HPS) and Fracture Critical Materials (FCMs)
During steel bridge fabrication where often thick plates must be butt welded together, the electroslag welding process is attractive for its efficiency and higher quality, being a single pass process. Historically, the process suffered from poor toughness and was not allowed for use in steel bridge fabrication of tension members from 1979 through 2000. In the 1980s and 1990s the Federal Highway Administration funded research to revamp the electroslag process (see references 1 through 9) that resulted in welds with improved toughness. The FHWA research resulted in what was adopted into the AASHTO/AWS D1.5 Bridge Welding Code (D1.5) as the narrow-gap electroslag welding (ESW-NG) process. As adopted into code, the process reflected in clause 4, part F of D1.5 is the narrow gap process but referred to there as “ESW”. Two barriers to broader acceptance of ESW-NG are, 1) it is not allowed for joining high-performance steel (i.e. ASTM A709 grades HPS50w, HPS70W, and HPS100W) and, 2) it is not allowed in fracture critical member. The first barrier is a function that HPS steel did not exist in the time period the ESW-NG process was in development, though these steels are being used in modern bridges. The second barrier does not represent a technical limitation of the welding process; it was a conservative approach taken by the committees overseeing the Bridge Welding Code to limit its use to let the welding process ease back into fabrication practice. It has now been 15 years since the ESW-NG welding process has been allowed for steel bridge fabrication and numerous fabricators now routinely use the process, and there is now a need to demonstrate its effectiveness for use with high performance bridge steels and in fracture critical members
The objective of this research is to establish the suitability of ESW-NG for welding high performance steel and fracture critical butt splices in steel bridges. The research must also provide design and fabrication specification recommendations associated with using ESW-NG in these applications.
This work supports AASHTO Subcommittee of Bridges and Structures 2013 Strategic Plan objective of “Optimize Structural Systems”.
|Sponsoring Committee:||AKC70, Fabrication and Inspection of Metal Structures
|Research Period:||12 - 24 months|
|RNS Developer:||Ronnie Medlock Vice President, High Steel Structures 1915 Old Philadelphia Pike Lancaster, PA 17602 firstname.lastname@example.org Justin Ocel, PhD, PE Structural Steel Research Program Manager Federal Highway Administration 6300 Georgetown Pike McLean, VA 22101 email@example.com|
|Source Info:||1. Atteridge, D. G., Devletian, J. H., and Wood, W. E. (1994). “Heat-Affected Zone Toughness of Electroslag Weldments.” Federal Highway Administration. McLean, VA.|
2. Atteridge, D. G., Devletian, J. H., Turpin, R. B., and Wood, W. E. (1994). “Industrial Field Trials of Oregon Graduate Institute Developed Electroslag Welding Technology.” Federal Highway Administration. McLean, VA.
3. Malin, V. (1995). “Training Manual for Narrow-Gap Improved Electroslag Welding for Bridges - Final Report.” Federal Highway Administration. Washington, D.C.
4. Malin, V. (1995). “Proposed Specifications for Narrow-Gap Improved Electroslag Welding - Final Report.” Federal Highway Administration. Washington, D.C.
5. Malin, V. (1996). “Process Operational Guide for Narrow-Gap Improved Electroslag Welding – Final Report.” Federal Highway Administration. Washington, D.C.
6. Malin, V. (1996) “Technical Information Guide for Narrow-Gap Improved Electroslag Welding – Final Report.” Federal Highway Administration. Washington, D.C.
7. Prine, D., Oleksy, J., and Malin, V. (1996) “Simulation of Electroslag Weld Defects - An Intermediate Report on Acoustic Emission Monitoring of Electroslag Welding.” Federal Highway Administration. Washington, D.C.
8. Wood, W. E., and Devletian, J. H. (1987). “Improved Fracture Toughness and Fatigue Characteristics of Electroslag Welds.” Federal Highway Administration. Washington, D.C.
9. Wood, W. E., Devletian, J. H., Atteridge, D. G., and Turpin, R. B. (1994). “Repair of Process Related Defects in Electroslag Welding.” Federal Highway Administration. Washington, D.C.
10. Swanson, J. A., Linzell, D. G., Bennett, C. R., and Lin. M. (2006). Verification of Performance and Design for High Performance Bridge Steels. Report Number FHWA/OH-2006/2. Ohio Department of Transportation. Columbus, OH.
|Index Terms:||Steel bridges, Prefabricated bridges, Butt welds, Electroslag welding, Toughness, Bridge members, Fracture properties, |
Bridges and other structures