Promoting Ti4C2S2 strain induced precipitation during asymmetrical hot rolling to improve r value and advantaged texture in Ti stabilized IF steel

The kinetic of Ti4C2S2 strain induced precipitation in a Ti stabilized IF steel was investigated using two stage interrupted compression test with high true strain (0.5). The PTT (precipitation-time-temperature) diagram was obtained by plotting 1/Ar-time curves. TEM (transmission electron microscopy) observation confirmed that the evolution of Ti4C2S2 precipitate in the quenched samples of thermal simulation is in good agreement with the PTT diagram. Hot strips were produced at three different rolling temperatures with high strain and slight shear deformation. It was found that hot rolling at the nose temperature of the Ps line of the PTT diagram can effectively promote the precipitation of Ti4C2S2 and retard the precipitation of TiC. Cold rolled and annealed sheets from hot strip containing higher volume fraction of Ti4C2S2 exhibited higher r value and stronger γ fiber texture with equal {1 1 1}〈1 1 2〉 and {1 1 1}〈1 1 0〉 components. By contrast, cold rolled and annealed sheets from hot strips containing lower volume fraction of Ti4C2S2 represented lower r values and weaker γ fiber texture with significant drops from {1 1 1}〈1 1 2〉 to {1 1 1}〈1 1 0〉 component.