The fierce competition between different steelworks and between different alloy design approaches keep promoting the development of new microalloyed structural steels which must satisfy increasingly severe mechanical strength and toughness requirements. Another equally desirable aspects for these new materials are the supression of heat treatments and better weldability, which makes this evolution even more complex. As weldabiliby improvement requires minimization of the carbon content of the steel, these new steels must present hardening mechanisms which does not require the presence of this element. Up to this moment, the most feasible answers to this challenge are steels hardened by copper precipitation, like HSLA-80 or ASTM A710, and the so-called Ultra Low Carbon Bainite (ULCB) steels.
HY-80; microalloyed steel; mechanical properties
