Continuous Temperature Measurement in Liquid Steel in the Ladle for the Quality Control of Cast Pieces

摘要

The adequate control of the pouring temperature of liquid metal is important to the production of quality castings. Casting the liquid metal at too low or too high temperatures can cause defects as the inappropriate microstructure, low mechanical properties, misruns; this is when the liquid metal solidifies before the filling of the mold, among others type of defects. Measuring the temperature of the liquid metal in the ladle before casting is a key factor to have a better quality of the cast pieces. Based on this important need, a continuous temperature measuring system was developed for the ladle. This system consists on continuous Platinum thermocouple installed through the ladle wall. This thermocouple has an Alumina- Graphite sleeve and can measure the temperature since the preheating of the ladle, tapping of the liquid metal from the furnace, during the transfer of the ladle to the casting point, and finally measures the exact temperature of the casting liquid metal has it gets into the molds. This thermocouple is placed on the bottom of the ladle, very near from where the liquid metal is cast to the molds. This gives a precise temperature control of the metal as is pouring.