Cryogenic Super-Tough Steel for Bridges and Other Applications

Higher toughness in steels permits the presence of longer fatigue cracks prior to rupture making it less likely that they would escape detection. Since steels become brittle at cryogenic temperatures, a steel with higher fracture toughness at low temperatures than existing steels is of interest for infrastructure applications such as bridges and tank cars. A steel (ASTM A710 Grade B) was developed at Northwestern University with FHWA and ITI financial support and with Illinois Department of Transportation (IDOT) participation for bridge and other infrastructure applications This steel has a minimum of 70-ksi-yield strength significantly outperform previously used ASTM A36 and ASTM A588 bridge steels in strength, weldability and fracture toughness at low temperatures. There is interest in a steel with even much higher than for A710 Grade B steel fracture toughness at cryogenic temperatures for use by Northern states Departments of Transportation (DOTs) and also for tank cars that transport cooled liquids such as liquid chlorine. The project proposes to develop and test a cryogenic super-tough steel by composition modification of our previously developed A710 Grade B steel. Based on prior steel-development experience the project will select 2-3 compositions, order heats from CANMET and in collaboration with IDOT and Union Tank Car Company (UTLX) will thoroughly investigate the mechanical, fracture, microstructural, welding and corrosion properties of steels. The project will select the optimal composition for commercial implementation. The project will contact Northern states DOTs and steel mills to market the steel for infrastructure as well as for other applications. The project expects that at least one steel company will produce a small commercial heat and evaluate the mechanical properties. During the performance of the project we will prepare documentation for inclusion of the steel into appropriate standard. The project also expects the cryogenic super-tough steel to respond to a need for a more fracture resistant steel for infrastructure, tank car, Homeland Security and other fracture critical applications.


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Filing Info

  • Accession Number: 01468454
  • Record Type: Research project
  • Source Agency: Center for the Commercialization of Innovative Transportation Technology
  • Contract Numbers: Y1-02
  • Files: UTC, RiP
  • Created Date: Jan 3 2013 3:51PM