Effect of Heating and Thermal Deformation on Austenite Grain Size of B1500HS Boron Steel

To investigate the effect of temperature and soaking time on the austenite grain size of B1500HS boron steel, samples of B1500HS steel were, respectively, heated at 900, 925, 950, 975, and 1000°C for 10, 20, 40, and 60 min, and the grain sizes of austenite for the heated samples were measured. Besides that, samples of B1500HS steel were heated at 1000°C for 10, 20, and 40 min by the thermo-mechanical simulator Gleeble-1500D, and then deformed with the deformation of 10, 20, and 30 % at the strain rate of 0.1 and 0.5 s−1, respectively, the effect of deformation degree and strain rate on the grain size of austenite was also studied. The experimental results showed that the average grain size of austenite rises with the increase of austenitization temperature and soaking time, but the average grain size reduced with the increase of deformation degree and strain rate. Finally, a grain growth model of B1500HS steel was given according to the experimental results.