Abstract: A device and method for recycling of gas used during the quenching process in a thermal treatment, for example, in which the gas is removed directly from a quenching chamber and is compressed to the pressure prevailing in the high-pressure container rather than being decompressed into a gas buffer, an additional compression step being connected if the pressure inside the chamber lies below a threshold value, wherefore conduits comprising overflow regulators lead to the individual compression steps.

Abstract: A method and a device for carburizing at subatmospheric pressures. According to said method, a treatment gas containing hydrocarbons is supplied to a treatment chamber and an exhaust stream exits said chamber. The opacity of the gas atmosphere that prevails in the treatment chamber and/or the opacity of the exhaust stream that exits said chamber is/are determined and the supply of the treatment gas containing hydrocarbons to the treatment chamber is regulated in accordance with the opacity that has been determined. If an opacity value that has been set or can be set is exceeded, the supply of the treatment gas containing hydrocarbons to the treatment chamber can be interrupted, or the quantity of treatment gas containing hydrocarbons that is supplied to said chamber can be reduced.

Abstract: For the annealing of steel in continuously operating units, the formation of so-called white dust is almost completely eliminated by subjecting the steel to a deoxidizing pretreatment before the annealing sequence so as to at least largely remove the oxygen adsorbed on the surface of the steel, as well as any oxygen compounds also present on the surface.