PROCESS AND FURNACE FOR THE BORO-CARBO-VANADIZATION OF PIECES AND MACHINE COMPONENTS

摘要

The invention relates to a process for boro-carbo-vanadization of pieces and to a furnace for carrying out the process. According to the invention, the process consists in coating the pieces with an alloy paste containing 33% graphite, 15% Fr-B, 7% Fe-V, 5% barium carbonate, 28% ethyl alcohol and 12% synthetic resin, packing the pieces placed in an electric furnace with a granular carburizing mixture consisting of graphite particles ranging from 0.1 to 0.4 mm with a content of barium carbonate or sodium carbonate of 8% at the most and a humidity of 5% at the most, supplying with direct current up to a piece-measured temperature of 900...1000°C and a granular material-measured temperature of 1000...1100°C, respectively, maintaining said temperature interval for 1.5...2 hours, followed by the simultaneous cooling of the piece and the electric furnace down to 300°C. The claimed furnace comprises an enclosure confined by two removable walls which permit the enlargement or narrowing of the working space on a hearth, in the removable walls there being embedded some graphite electrodes, some systems for discharging waste gases with a cover wherethrough there are introduced some thermocouples, a voltmeter and an ammeter.