PECULIARITIES OF TEMPERATURE AND OXIDATION CONDITIONS DURING RH VACUUM DEGASSING

Abstract

The paper presents the results of analyzing the production of IF steels (Interstitial Free – steels without interstitial atoms) in a modern converter shop. These steels are widely used in the automotive industry for manufacturing body components. A comprehensive assessment of the current technological scheme for the production of IF steels was carried out, indicating its main shortcomings. An array of production data and parameters from current production melt certificates, as well as experimental melt certificates with an increased number of melt parameter control data were analyzed. According to gas analysis parameters, the moment of completion of metal decarburization during vacuum treatment was confirmed experimentally, which made it possible to establish the optimal time for deoxidation and microalloying processes. Based on the analysis, an empirical formula was obtained for changing the metal temperature over the entire vacuum treatment cycle, as well as providing a margin of metal temperature for further casting on a continuous casting machine. Taking into account the obtained data, a technological scheme for producing IF steels is proposed, which eliminates the need to return metal after vacuum treatment to the ladle-furnace unit, or eliminates the need for electric arc heating after vacuum treatment. The article also presents the results of practical verification in the production conditions of the converter shop. Successful testing of the results of the study made it possible to reduce the consumption of materials that are used in the deoxidation and microalloying of metal, as well as to reduce the total time of ladle processing of metal in both single-melt and mass production of steel of the IF grades.