【正文】
OF THE METAL TEMPERATURE IN 50TON CONVERTERS BY MEANS OF HERMOCOUPLES PROTECTED BY CERMET ZIRCONIUMBORIDE END CAPS S. M. Serdyuk, M. I. Korobko, S. K. Sobolev, A. S. Sizenko, B. K. Kachur, and K. R. Vlasov Institute of Automation of the State Planning Commission, Ukr. SSR, and Institute of Problems in the Study of Materials, Academy of Sciences, Ukr. SSR Translated from Poroshkovaya Metallurgiya, No. 1 (19), pp. 9195, JanuaryFebruary, 1964 Original article submitted September 6, 1968 The quality of steel and the output and efficiency of converter production during the smelting process depend to a considerable extent on the metal temperature. Therefore, continuous temperature control is necessary during the blowingthrough process. Measurement by means of thermocouples is considered to be the most efficient method for measuring the temperature of the liquid metal. A tungstenmolybdenum, a tungstenmolybdenum with aluminum (Central Scientific Research Institute of Ferrous Metallurgy), a platinorhodiumplatinum, and a platinorhodiumplatinum PR 30/6 thermocouple were tested during the operation of a 50ton converter under industrial conditions. It was found that the most stable thermocouple with the necessary metrological characteristics was the PR 30/6 thermocouple. All the subsequent experiments were performed with this thermocouple. In order to protect the thermocouple from destruction by liquid metal, we used threelayer gastight end caps, which were developed on the basis of heatresistant zirconiumboride cases. The durability of zirconiumboride end caps was basically determined with respect to the chemical action which the stag exerted on them and with respect to the erosion wear caused by metal flow. It is known [1, 2] that zirconiumboride end caps can be exposed to liquid metal in Martin furnaces for several hours. Their high refractoriness and chemical stability in molten steels can be explained by the strong chemical bond of the pound, in which, besides valence electrons, also electrons of internal inplete electron shells of the element39。s atoms participate, and also by the structure of borides, where the frame of the crystal lattice consists of boron atoms [5]. The operating conditions of zirconiumboride end caps are more severe in an oxygen converter, since there are large