Heating Kinetics upon Microarc Thermo-Chemical Treatment of Steel Products

Abstract

A process temperature is studied during microarc thermo-chemical treatment of steel product immersed in a container with powdered coal and heated by electric current. Feature of the process consists in formation of microarc discharges concentrated around the product. Theoretical temperature of coal combustion is calculated. Platinum-platinum-rhodium thermocouple is used for measurements. Thermocouple contacts are connected to a digital multimeter and then gained information is transmitted to a personal computer. Experimental time dependence of the sample surface temperature exhibits 4 sections corresponding to different kinetics of sample heating. A decrease in the sample heating rate within a temperature range of 200 - 270 °C is attributed to endothermic reactions in the coal whereas stabilization of the sample temperature at a level of 1250 °C is associated with the special features of heat release during combustion of coal in the working cell.