Grain refinement by intragranular nucleation of ferrite in a high nitrogen content vanadium microalloyed steel

The intragranular nucleation of ferrite was studied in a hot strained V-microalloyed steel. By means of torsion tests, the recrystallized fraction was determined for a strain of 0.35 and temperature of 950 °C. Tests at the same strain and holding times corresponding to the start and end of precipitation with subsequent cooling of the specimen showed that the intragranular nucleation of ferrite on VN precipitates leads to a significant decrease in the grain size, close to 50%.