Precipitation of Aluminium Nitride in a Low Carbon, Aluminium and Calcium Deoxidized Steel during Recrystallization

Abstract

By means of a low frequency internal friction method the combined effect of nitrogen and aluminium of the cold rolled rimmed steel, aluminium and calcium deoxidized steels has been studied during isothermal or isochronal annealing. For these materials which formed typically elongated pancake grains as shown in a previous report, the lowering of nitrogen in solution during the recovery to the early stage of recrystallization was attributed to fine precipitation of aluminium and nitrogen on the grain boundaries or subboundaries of the matrix. It has been assumed that the aluminium calcium deoxidized steel possesses the superior characteristics of a stabilized steel, because the solubility of carbon and nitrogen in α iron of the aluminium calcium deoxidized steel was considerably low compared with that of aluminium deoxidized steel.