Material development for high-performance bridge steels

A program sponsored by the Federal Highway Administration (FHWA) is underway to develop high-performance (more weldable, high-strength, high-toughness) steels for the bridges of tomorrow. It is intended that these new high-performance steels be used in current-design bridges as well as in new bridge designs being developed as part of a parallel program sponsored by FHWA. A three-year steel development program to tailor candidate high-performance steels to bridge requirements is being implemented by the American Iron & Steel Institute (AISI). As part of an initial six-month laboratory screening study, U. S. Steel and Bethlehem Steel produced and evaluated plates of several experimental weathering steels (i.e. steels with good atmospheric corrosion resistance) that were processed by different rolling and heat-treatment practices. A hot-rolled and quenched-and-tempered 0.08%C A852 steel exhibited a very good combination of strength and toughness and appears to be an excellent candidate for a mom weldable 480 MPa bridge steel.