L. Lee, Worcester Polytechnic Institute, Worcester, MA

Summary: An experimental investigation has been conducted on the 4140 steel and IVF quench probe to quantify the influence of water flow rate and droplet distribution on the cooling rate and heat transfer coefficient. Time-temperature data has been collected for each spraying condition by using spray quenching system. Heat transfer coefficients as a function of temperature have been estimated using lumped parameter analysis. The results from this study indicate that the heat transfer coefficient of spray quenching is higher than that of the traditional immersion quenching. It is also found the cooling rate decreases with the decrease in the flow rate. Slight variation is seen in the influence of droplet distribution at high flow rate.