Abstract: The behaviors of different inhibitors including their composition, size, distribution, coalescence and coarsening were experimentally studied. It was observed that during secondary recrystallization of the tested steel, the key inhibition effect was produced by Cu₂S and AlN, but not MnS. With the increase of temperature, the size distributions of AlN and Cu₂S were changed to some extent. However, significant changes in particle size were not observed. The initial temperature of abnormal growth was determined by measuring the evolution of particle sizes and their distribution density during heat treatment. AlN and Cu₂S are the dominant inhibitors and both are necessary, which is verified by calculating the Zener factor.