Development of high strength steels

Abstract

The physical metallury as a background to the strength and toughness of high strength, low-alloy wrought steels (yield strength above 350 MPa) is considered. The strengthening mechanisms: solid solution hardening by alloying, grain size control by thermontechnical processing, precipitation hardening by microalloying, as well as dislocation, substructure and texture hardening during rolling in the two-phase region are dealt with for low carbon ferritic-pearlitic steels. Acicular ferritic, bainitic and low alloyed martensitic quench and tempered steels are also briefly described. The benefits of low carbon equivalent and Ti-alloying for weldability ad inclusion shape control for formability in high strength structural steels are discussed.