Process for continuously coating a filamentary steel article by immersing the article in a bath of the molten coating metal

摘要

The steel wire (2) to be coated is passed through the graphite nozzle (7) of a crucible (8) filled with a bath (9) of molten metal, after having been preheated in a tubular conduit (13) filled with protective gas by an electrical coil (16) supplied with a high frequency (HF) source, to a temperature below that of the molten metal contained in the nozzle (7). The melting temperature of this metal is higher than the austenisation temperature of the steel. On leaving the nozzle (7) the coated steel wire is then cooled in a controlled manner to prevent it being quenched, for example, when a steel with less than 7% of carbon is involved, by being passed for a few seconds through a fluidised bed (17) whose temperature is maintained at a temperature of the order of 550 DEG C. IMAGE