Nb(C,N) precipitation kinetics in the bainite region of a low-carbon Nb-microalloyed steel

Nb(C,N) precipitation in the bainite region (580–660 °C) of a low-carbon Nb-microalloyed steel was investigated by electrical resistivity and transmission electron microscopy. Nb(C,N) particles started precipitating after 100–200 s at isothermal temperatures after bainite transformation and cementite formation, and precipitation finished in 1000–2000 s. The precipitation-time–temperature diagram of Nb(C,N) in the bainite region of a low-carbon microalloyed steel was a type of C-curve, with a nose temperature of about 615 °C.