Thermal Design of CCM Mold with Slotted Water Cooling Channels

The problem of redesigning the wide walls of the CCM-2,3 molds at the oxygen-converter plant of the Magnitogorsk Iron and Steel Works is solved due to the need to change over from copper plates with drilled channels to copper or bronze cassette-type plates with slotted cooling channels and hardening coating. The redesign of the mold walls should not affect the loop circuit for supplying cooling water and pouring metal into a twin mold. When creating the thermal model of the new wide wall with slotted cooling channels, the existing thermal design methods were analyzed. The temperature drops of the cooling water and the dependence of the average surface temperature of the cooling channels on the pouring rate and the speed of water in the channels are obtained. The temperatures of the wall without coating, with nickel–cobalt and with steel coating 3 mm thick depending on the metal pouring rate for different speeds of cooling water in the channels are determined. A thermal model of the wide plate of the mold of new design is created. It allows analyzing the thermal parameters of the wall with slotted channels and hardening coating for different operating conditions of the CCM. It is established that the temperature of the surface with coatings is 1.3 to 1.5 times higher than without coating. In addition, the coating can significantly increase the overall thermal resistance of the wall. It is recommended to apply a wear-resistant coating only to the lower, most wearing part of the mold plates.