Abstract
In the quenching process, heat transfer behavior will is very complex due to boiling, generation of the bubble by the boiling in the quenchant, flaking off of steam film in metal surface. In this research, the behavior of steam film in quenching process was investigated with high-speed video camera by visualization method. The behaviors of the boiling bubbles including generation and movement as well as the breaking during stirring quenching process were clarified. The flow velocity fields around the quenching parts at no stirring and stirring quenching with various flow velocities on nozzle were investigated. In order to identify the heat transfer coefficients by using of the measured cooling curves of surface temperature. Effects of stirring and oil temperature on breaking the steam film were confirmed.
