PROCEDE DE CEMENTATION RAPIDE DANS UN FOUR CONTINU

PROCEDE DE CEMENTATION RAPIDE DANS UN FOUR CONTINU FERME DANS LEQUEL ON INJECTE UN GAZ PORTEUR ET UN HYDROCARBURE SUSCEPTIBLE D'ENGENDRER AUX TEMPERATURES USUELLES DE CEMENTATION, UNE ATMOSPHERE DE COMPOSITION PREDETERMINEE AYANT UNE CONCENTRATION NOMINALE EN MONOXYDE DE CARBONE, UNE PORTE DU FOUR ETANT OUVERTE PERIODIQUEMENT POUR PERMETTRE LE PASSAGE D'UNE CHARGE A CEMENTER, L'OUVERTURE DE CETTE PORTE ENGENDRANT NOTAMMENT UNE AUGMENTATION DE LA CONCENTRATION DES ESPECES OXYDANTES DANS L'ATMOSPHERE DUDIT FOUR.SELON L'INVENTION, ON AUGMENTE LA CONCENTRATION EN MONOXYDE DE CARBONE DE L'ATMOSPHERE INJECTEE DANS LE FOUR, DE MANIERE A COMPENSER L'AUGMENTATION DE LA CONCENTRATION EN ESPECES OXYDANTES DU FOUR ET MAINTENIR AINSI SENSIBLEMENT CONSTANT LE POTENTIEL CARBONE DE L'ATMOSPHERE DE CEMENTATION DU FOUR PENDANT TOUTE LE DUREE DE CEMENTATION DESDITES PIECES. Process in which there are injected a carrier gas and a hydrocarbon capable of producing, at conventional carburizing temperatures, an atmosphere of predetermined composition having a nominal concentration of carbon monoxide, a door of the furnace being opened with a given periodicity to permit the passage of a charge to be carburized, the opening of this door resulting in particular in an increase in the concentration of the oxidizing species in the atmosphere of the furnace. According to the invention, the concentration of carbon monoxide of the atmosphere injected into the furnace is increased with the same periodicity so as to compensate for the increase in the concentration of the oxidizing species of the furnace and thus maintain the carbon potential of the carburizing atmosphere of the furnace substantially constant throughout the duration of the carburization of the workpieces of the charge.