Hardenability of austenite in a dual-phase steel

A low-carbon, low-alloy steel was intercritically heat treated and thermomechanically processed to study the martensitic hardenability of austenite present. Rolling of the two-phase (α+γ) microstructure elongated austenite particles and reduced their martensitic hardenability because the α/γ interface where new ferrite forms during cooling was increased by the particle elongation. The martensite particles obtained in rolled material were also elongated or fibered in the rolling direction. Therefore, the thermomechanical processing of a two-phase (α+γ) mixture has the detrimental effect of increasing the quenching power needed to yield a specific amount of martensite.