Effects of Finishing Rolling Temperature and Cooling Rate after Rolling on Microstructure and Hardness of 20CrMnTi Steel Bars

The hot deformation behavior of the bars was discussed by means of hot compression tests on the MMS-200 thermal simulator. The differences of microstructure and mechanical properties corresponding to different final rolling temperature and cooling rate of steel was studied. The results indicated that the bars would obtain fine and uniform isometric crystal when the finishing temperature and cooling rate of 20CrMnTi bars was 950 ℃ and 0.2-0.3 ℃·s-1, therefore the hardness can be controlled at about 197 HBW.