The Effect of Fast Heating in the Grain Growth of Prior Austenite Grain Size

In recent years, the development of induction heating has been adopted by various heat treatment industries. Beyond its decarbonization benefits, induction heating offers an advantage in terms of austenite evolution due to the increased heating rate during heat treatment, compared to combustion furnaces. It is known that high heating rates influence the refining of austenite grain size when compared to slower heating rates in a furnace. The present work analyzes the effect of fast heating rates in SAE 9254 steel at heating velocities between 10-300 °C/s, with soaking temperatures of 900°C and 950°C. To perform the measurements, Vilella etching was used, employing an oxidation method at 950°C for 1 minute, and the heat treatments were performed using a Gleeble machine. The testing revealed that slower heating rates result in coarser PAGS (Prior Austenite Grain Size).