Experimentally Based Study on the Effect of Initial Grain Size for Characterization of the Grain Coarsening Phenomenon During Hot Rolling of a Medium Carbon Steel

摘要

Laboratory experiments using a hot deformationsimulator were carried out to clarify the effect of initial grain sizeon the grain coarsening phenomenon in hot metal working withlight reduction. As an example of amdium carbon steel, AISI1045was adopted and specimens of various grain sizes were preparedby changing the thermo-mechanical histories. They weresubjected to a hot deformation testing by the simulator. Thethreshold grain size to cause the grain coarsening phenomenonwas then determined and a criterion was presented to ensure afine grain after hot rolling. The validity of the new criterion waschecked through hot rolling of bars by a prototype mill in a laboratory.