Effect of Flow Rate of Cooling Water on the Interfacial Heat Transfer Coefficient between Modular Water-Cooled Mold and Casting

In this work, the effect of flow rate of cooling water on interfacial heat transfer coefficient was studied using ZG230-450 and a newly designed modular water-cooled mold. The temperature profile of casting during the solidification process was first measured at different flow rates of cooling water. The measured temperature profile was then used to calculate the interfacial heat transfer coefficient (IHTC) of cast/water-cooled mold through solving the inverse heat conduction problem. Based on the calculated interfacial heat transfer coefficient, the effect of flow rate of cooling water on interfacial heat transfer coefficient was further analyzed. The results indicate that interfacial heat transfer coefficient increases with the increase of flow rate of cooling water. When the interfacial temperature of the casting exceeded 1500K, the interfacial heat transfer coefficient increased from 1000 to 1700 W/m(2).K as the flow rate of cooling water increased from 2.6 to 5 m/s. As the interfacial temperature decreased, the difference in the interfacial heat transfer coefficient at different flow rates of cooling water also became lower, while a similar trend of IHTC versus flow rate of cooling water was observed. At the same flow rate, IHTC was larger at the early stage of solidification, following the formation of a solidification layer on the cast, IHTC first plummeted and then decreased more gradually. IHTC showed large variation during the cast solidification process.