Abstract: ]Kinetics behavior of MnS and AlN particles nucleation precipitation in low temperature grain oriented silicon steel at different heating temperatures during hot rolling was calculated and analyzed by using thermodynamics and kinetics interrelated theory．The results showed that the critical nucleation size of dislocation nucleation is the smallest. AlN particles are nucleated preferentially under the homogeneous nucleation and dislocation nucleation mechanisms, while the MnS particles are nucleated preferentially under the grain boundary nucleation mechanism. The main nucleation mechanism of MnS particles is grain boundary nucleation. The main nucleation mechanism of AlN particles is dislocation nucleation at the temperature below 1 323 K. During the hot rolling process, the precipitation time of AlN particles is the shortest at grain boundary when the temperature is higher than 1 425 K, while it is the shortest at dislocation when the temperature is below 1 425 K. The precipitation behavior of MnS particles is consistent with that of AlN particles, but the corresponding temperature is 1 450 K. After the slab is rolled out, AlN and MnS mainly precipitate at grain boundaries. After the rough rolling process, with the increase of deformation amount and the rise of dislocation density, it is conducive to the precipitation of inhibitors along dislocations.

Key words: grain oriented silicon steel, AlN, MnS, nucleation mechanism, precipitation