Abstract: The invention relates to a method for controlling the decarburization of steel components in a furnace during heat treating processes. The concentration of CO2 and/or CO in the furnace is monitored in a first batch in order to determine periods of elevated CO2/CO concentrations, and inert gas is injected in subsequent batches during the previously determined periods of elevated CO2/CO concentrations.

Abstract: The invention relates to a method and apparatus for controlling the decarburization of steel components in a furnace during heat treating processes. The concentration of CO2 and/or CO in the furnace is monitored by an analyzer. Responsive to a signal from the analyzer indicating an elevated concentration of CO2 and/or CO, a gas injector injects inert gas into the furnace at a flow rate of at least about 2 renewals per hour.

Abstract: A plant for generating a nitrogen-based gas is provided. The plant includes a source of impure nitrogen under pressure containing a residual oxygen concentration; a main gas conduit; a catalytic deoxygenation reactor; a secondary gas line connected to a source of a secondary reducing gas at one end thereof and to the main gas conduit at a point situated upstream of the catalytic deoxygenation reactor at another end thereof; and a device for removing water vapor present in a gas. The source of impure nitrogen is connected to the catalytic deoxygenation reactor via the main gas conduit. The main gas conduit between the source of impure nitrogen and the point where the secondary gas line is connected is devoid of any flow control device.

Abstract: A process for generating a nitrogen-based gas, comprising the steps of:(i) combining a secondary reducing gas including at least one reducing gas with a primary nitrogen gas including 0.5-5% by volume of oxygen, the combining of the secondary gas being performed according to an uncontrolled all-or-nothing method;(ii) reacting the primary gas and the secondary gas in a catalytic deoxygenation reactor so as to obtain a nitrogen-based reaction gas which includes water vapor; and(iii) removing at least a part of the water vapor present in the nitrogen-based reaction gas by cooling the reaction gas under pressure to induce formation of a liquid phase and then extracting the liquid phase from the reaction gas under pressure to obtain a purified reaction gas.

Abstract: The thermal treatment atmosphere is obtained by catalytic reaction of an impure mixture of nitrogen, advantageously obtained by permeation or adsorption, and hydrocarbon, the catalytic reaction being carried out at a temperature between 400.degree. and 900.degree. C., typically between 500.degree. and 800.degree. C., with a noble metal base catalyst, typically platinum or palladium on alumina support. The reaction may be carried out in a reactor placed inside or outside the furnace.

Abstract: Metallization of ceramics of the type comprising depositing a metallic paste based on molybdenum and/or tungsten and manganese on a ceramic substrate and effecting the sintering of the paste in an atmosphere having a predetermiend oxido-reduction potential, with a rise in and a maintenance of a temperature between 1300.degree. C. and 1600.degree. C., then cooling to ambient temperature, with production of an atmosphere by the addition to a pure neutral gas of a quantity of additional oxygen and a quantity of hydrogen at least sufficient to subsequently obtain by catalytic reaction the desired content of water vapour and contingently the excess content of hydrogen.

Abstract: The invention concerns the production of ceramic-metal multilayer components comrising effecting, after making up in the crude state, in particular by metallization and stacking of pre-cut raw ceramic bands, a simultaneous firing operation, termed cofiring, on the components under an atmosphere based on hydrogen or nitrogen or a mixture of hydrogen and nitrogen, having a regulated water vapor content at a temperature of first of all between 800.degree. C. and 1800.degree. C., and more precisely either at a moderately high temperature plateau between 800.degree. C. and 1300.degree. C. for certain ceramic materials such as codierite and metallic materials such as copper and nickel, or at a temperature plateau between about 1400.degree. C. and 1800.degree. C.

Abstract: Heat treating metals by continuous longitudinal passage of metallic pieces in an elongated treating zone under controlled atmosphere having a high temperature upstream end where the controlled atmosphere comprises nitrogen and reducing chemical substances, such as hydrogen, possibly carbon monoxide, and a downstream cooling end under an atmosphere essentially formed by introducing nitrogen. In the high temperature upstream end, the nitrogen which constitutes the atmosphere is supplied by introducing nitrogen with a residual oxygen content not exceeding 5%, the reducing chemical substances being present at any moment in amounts at least sufficient to eliminate oxygen introduced with nitrogen. The nitrogen introduced in the downstream cooling end is substantially free of oxygen. Application of the process to the annealing of metallic pieces.

Abstract: Process for thermal treatment of metals by passage of metallic pieces into an elongated zone under a controlled atmosphere, having an upstream section at an elevated temperature, where the controlled atmosphere comprises nitrogen and reductive chemicals, particularly hydrogen, possibly carbon monoxide; and a downstream section at a lower temperature under a controlled atmosphere. The invention is characterized by the fact that in the upstream section at an elevated temperature, the atmosphere comprises nitrogen having a residual content of oxygen between 0.5% and 5% produced by separation of air using permeation or adsorption techniques. The reductive chemicals are present at all times in a content at least sufficient to eliminate the oxygen admitted with the nitrogen.

Abstract: The invention concerns glass-metal sealing comprising effecting on a metallic piece, in particular an alloy based on iron and nickel or iron, nickel and cobalt, first of all a decarburization under an atmosphere, at a temperature of between 950.degree. C. and 1,150.degree. C., formed by hydrogen (10 to 99%), water vapor (1 to 8%), with a ratio hydrogen/water vapor higher than five, the possible remainder being nitrogen, then an oxidation under an atmosphere formed by an inert vector gas such as nitrogen, either at a temperature of 600.degree. C. to 800.degree. C. and with a water vapor content of 8% to 2%; or at a temperature of 900.degree. C. to 1,100.degree. C. and with a water vapor content of 4% to 0.5%; then establishing the connection.