Abstract: The method for quenching a steel charge after carburizing or carbonitriding is carried out at atmospheric pressure and comprises the following steps: the charge is extracted from a treatment furnace (1) at a temperature ranging from 750 ° C. to 1100 ° C.; b) the charge is transferred to a quenching cell (3); c) a quenching fluid is introduced at a pressure which is higher than atmospheric pressure; d) the charge is cooled to a temperature of less than 400 ° C. According to the invention, the fluid is primarily composed of air, and the part is brought to a temperature of at least 400 ° C., whereby an oxide layer preventing decarburization is formed in the time period starting from the moment when the charge exits (1) from the furnace.

Abstract: The method for enriching steel with carbon by carbon oxide comprises a step involving heating to a temperature of enrichment in a furnace in a gaseous phase, then an enrichment step involving the introduction of a gas containing carbon oxide. According to the invention, atomic hydrogen is formed in said gaseous phase prior to the enrichment phase, said atomic hydrogen being of a sufficient amount to suppress interface resistance to the transfer of carbon and to avoid surface oxidation of said steel.

Abstract: An installation for heat treatment or thermochemical treatment of steel permit instantaneous and permanent checking of the concentration of carbon at the surface of the steel, particularly in the course of the carbon enrichment of the surface zone of a workpiece. The process provides for the circulation in contact with this surface zone of a gaseous flux permitting the saturation concentration of carbon at the surface to be obtained at maximum speed, and for regulating this flux as a function of time. The installation comprises a monitored-atmosphere furnace having an input and an outlet for a gaseous flux, feed means forming this gaseous flux, and means for regulating the gaseous flux; it is equipped with data-storage and/or calculating means, and the feed means are designed to form a gaseous flux suitable for obtaining a saturation concentration of carbon at the surface of the workpieces in less than one minute.

Abstract: A process and an installation for heat treatment or thermochemical treatment of steel permit instantaneous and permanent checking of the concentration of carbon at the surface of the steel, particularly in the course of the carbon enrichment of the surface zone of a workpiece. The process provides for the circulation in contact with this surface zone of a gaseous flux permitting the saturation concentration of carbon at the surface to be obtained at maximum speed, and for regulating this flux as a function of time. The installation comprises a monitored-atmosphere furnace having an input and an outlet for a gaseous flux, feed means forming this gaseous flux, and means for regulating the gaseous flux; it is equipped with data-storage and/or calculating means, and the feed means are designed to form a gaseous flux suitable for obtaining a saturation concentration of carbon at the surface of the workpieces in less than one minute.

Abstract: A high intensity ionic bombardment reactor for submitting a member to a thermochemical treatment process of the type comprising a current duct or conductor forming a support for said member and having the form of a cylindrical metal rod, and an insulant for insulating said conductor from the reactor walls, said reactor further comprising a tube supported by said insulant coaxially surrounding said rod and spaced therefrom by a constant distance which is as small as possible.