Simulation and measurement of aluminium-nitride precipitation in hot rolled Al killed low carbon steel coil.

Aluminium-nitride precipitation is of great importance in the deep drawability of Al killed low carbon steels. The industrial processing of Al killed steel has some critical points at which the drawability of the final product is strongly influenced by the processing parameters (hot rolling end temperature, coiling temperature). The nitrides are dissolved at the slab reheating temperature (1250°C), and most of the nitrogen remains in solid solution until the hot rolling finishes. The precipitation of nitrides in ferrite occurs more quickly than in austenite, consequently the coiling temperature must be enough low to keep the nitrogen in solid solution. The main purpose of this paper is to describe the aluminium-nitride precipitation process in hot rolled coil. Moreover, on the basis of a phenomenological model of the precipitation process the precipitated fraction of nitrides coiling has been calculated. [ABSTRACT FROM AUTHOR]