Abstract: A process for chemically treating a metallic part such as a part used in aerospace applications comprising providing a process tank capable of receiving at least one part; providing at least one part to the process tank; providing an alkaline first solution into the process tank from a first storage tank; providing the first solution from the process tank into a transition tank; providing water to the process tank; providing the first solution from the transition tank into the first storage tank; providing an acidic second solution into the process tank from a second storage tank; providing the second solution into the transition tank; providing water to the process tank; providing the second solution into the second storage tank; providing a third coating solution having a pH of about 1.0 to about 3.0 into the process tank from a third storage tank; providing the third solution into the transition tank; providing water to the process tank; and providing the third solution into the third storage tank.

Abstract: An apparatus for selectively implementing a depressurized or an atmospheric hydrogen annealing process comprises a reaction chamber, a hydrogen gas introduction line for feeding hydrogen gas into the reaction chamber and an atmospheric exhaust line and a depressurized exhaust line, which are connected to the reaction chamber. By selectively switching the atmospheric exhaust line and the depressurized exhaust line, the depressurized hydrogen annealing process and the atmospheric annealing process are selectively implemented. A device for performing deoxidization process or a device for removing impurities may be further included.

Abstract: A method is disclosed for reducing the formation of wrinkles on metal strip subject to cooling in continuous heat treatment lines in which the strip passes through cooling zones through which cooling gas flows. The method includes the step of gradually modifying the cooling intensity at each change in the slope of the cooling cycle.

Abstract: A system for the thermal treatment of work pieces with an explosive gas mixture, in particular, a thermal deburring system, has a processing chamber (10), which includes a combustion chamber (12) for receiving the work pieces. A supply channel (18) for the gas mixture opens into the combustion chamber (12). In the combustion chamber (12), a device is provided, which has a plurality of openings through which the flame front passes for thermally treating the work pieces. The device can be one that connects to the supply channel (18), preferably in the form of a tube (26) with a plurality of openings (28), which can be made from an extruded sheet. The work pieces obtain a more uniform processing or deburring effect, since the flame front passes through the many small openings of the device. The small openings (28) serve also as throttles, whereby the entire combustion process runs for a longer time.

Abstract: A method for quenching steel parts having undergone a low-pressure thermal processing, which consists of submitting the parts to a high-pressure air flow.

Abstract: Method for reducing the formation of wrinkles on metal strip subjected to cooling in continuous heat treatment lines in which the said strip passes through cooling zones having boxes provided with means for blowing a cooling gas, comprising the step of gradually modifying the cooling intensity at each change in the slope of the cooling cycle.

Abstract: Apparatus and process for recycling a quenching gas, such as helium, to be used with a treating gas, such as a carburizing gas, for the treating of components in an atmospheric furnace.

Abstract: Oxides on the surfaces of metal are reduced by directing reducing gases at them in a forceful and turbulent manner. In a preferred version, the gas is passed through at least two reducing zones designed to maintain a higher concentration of reducing gas in at least one of them than would be the case in a single reducing zone. The oxide-bearing surface is heated at the beginning of the process..

Abstract: This invention is directed to a method for annealing strand wires or strips in a fluidized bed reactor having an atmosphere of fluidized gases flowing through fluidized particles. The method provides for stratifying the atmosphere of fluidized gases by passing a reducing gas through the fluidized particles in the fluidized bed. The wires are passed between the fluidized particles at a location near the bottom of the fluidized bed. Finally, an amount of oxygen-containing gas is injected on top of said fluidized bed reactor.

Abstract: A carburization and quenching apparatus includes: a plurality of carburizing chambers for carburizing thin plate parts; a gas cooling chamber for cooling the thin plate parts carburized in the carburizing chambers; and a reservoir tank 3 connected to the gas cooling chamber for delivering a cooling gas into the gas cooling chamber. The plurality of carburizing chambers are positioned at an approximately equal distance from the gas cooling chamber to surround the gas cooling chamber.In a continuous furnace, thin plate parts can be transported successively at least between a carburizing chamber and a pressurized cooling chamber. The thin plate parts are carburized in the carburizing chamber and then rapidly quenched in the pressurized cooling chamber by cooling the thin plate parts with a pressurized gas which can be e.g. inert gas.

Abstract: In a roller hearth furnace there is provided an apparatus for scavenging cold-drawn, coil-forming tubes. An essential element thereof is a pressure vessel (1; 1a) serving as reservoir for the scavenging agent, comprising a small calculable outlet opening (2) and a coupling member (3) connected with the tube coil (4).

Abstract: In a method of and apparatus for controlling an atmosphere in a heat treatment furnace according to the present invention, a carburizing is carried out while supplying a hydrocarbon series gas and an oxidization gas into the furnace. The quantity of a residual CH.sub.4, a partial pressure of the oxidization gas and a partial pressure of CO are measured. The quantity of each gas to be supplied into the furnace is controlled according to either one of the values of the partial pressures.

Abstract: In a method of and apparatus for controlling an atmosphere in a heat treatment furnace according to the present invention, a carburizing is carried out while supplying a hydrocarbon series gas and an oxidization gas into the furnace, and the supply of the hydrocarbon series gas is stopped either when the quantity of a residual CH.sub.4 in the furnace is changed to increasing from decreasing, or when a partial pressure of oxygen in the furnace reaches a predetermined value.

Abstract: A nitriding process and nitriding furnace therefor wherein the parts to be treated are maintained at floating potentional in a vacuum furnace (9), current being provided to a metal screen (5) cathode surrounding the parts to be treated, the necessary heat being provided by radiation from screen (5) whereby nitriding gas is injected into the furnace such that it has to flow through screen (5) where the plasma necessary for the nitriding reaction is generated by glow discharge the plasma flowing around and reacting with the parts to be treated before it is evacuated at the bottom of furnace (9) through vacuum/exhaust conduit (2).

Abstract: An apparatus for the treatment of components by means of a gas mixture, comprising mainly a first light gas and minor amounts of a second gas being heavier than the first gas, has a treatment chamber (10) in which the treatment occurs and a concentration, and purification device (19, 29, 30) in which the gas mixture is concentrated and purified to increase the concentration of the first gas. The treatment chamber (10) comprises an outlet member (19) provided in an upper part of the treatment chamber (10) and means (14, 15) being arranged to move the gas mixture upwardly and out through the outlet member (19). Said means may comprise an inlet member (14) provided in a lower part of the treatment chamber (10) and arranged to supply additional gas and to admit a laminar inward flow of said additional gas.

Abstract: In order to harden the surface of workpieces having complex shapes without reviously applying absorption promoting surface layers, a mixture of inert gas and oxygen are supplied to the processing zone while the workpiece is exposed to laser radiation. The degree of absorption is maximized by adjusting at least one of the mixing ratio, the volume flow rate, and the processing temperature to conform to a nominal value.

Abstract: A workpiece is heated by first forming an ionized gas plasma around the workpiece. A positive potential is applied to the workpiece to accelerate electrons from the plasma into the workpiece. The workpiece is uniformly surface heated by the energy directed into the workpiece by the electrons. The workpiece is cooled by providing a flow of a pressurized liquid material such as carbon dioxide having a triple point. The liquid material is expanded through a nozzle to form solid particles that contact the surface of the workpiece and remove heat from it by subliming.

Abstract: Process for the continuous heat treatment of a metal strip, the latter travelling through a furnace, which is thermally insulated, and in a protective atmosphere; the said furnace consisting of at least one section, for heating, for temperature hold and for cooling; the said strip being guide by a plurality of rollers arranged especially in the lower part and in the upper part of the said sections, so as to form a plurality of runs, wherein the strip passes through at least one partial or total isolating device positioned within at least one section or between two sections, so as to ensure different heat transfer properties on the strip compared with at least one other adjacent section having a different atmosphere, by adjusting the composition of the atmosphere consisting of a gas mixture whose hydrogen or helium content exceeds 5% and more particularly 15%, in order to allow differentiation of the thermomechanical properties of the atmosphere.

Abstract: A system for the heat treatment of metallic annealing material (1, 12) comprising a distributor (3) for the heating or cooling medium consisting of air or a gas, where for the formation of an oblique blast the distributor (3) has tubular or slot-shaped nozzles (4, 4a) directed against the annealing material (1, 12) possibly lying on a transport means (2). For changing the distance of the nozzle orifice from the workpiece surface, the nozzles (4, 4a) are provided with retractable extensions (5, 5a) for increasing the distance between nozzle orifice and annealing material (1, 12).

Abstract: A method for controlling the CO contents of furnace atmosphere for carburizing and carbonitriding metallic workpieces in a furnace includes the step of directly feeding a mixture of an oxidizing reagent and a hydrocarbon-containing fuel into the furnace for producing a CO-containing furnace atmosphere. The CO contents of the furnace atmosphere is measured and compared to a preset minimal CO value. A CO-forming substance is introduced into the furnace atmosphere when the measured CO contents is no longer greater than the preset minimal CO value.

Abstract: A device for heat-treating metallic workpieces in a vacuum has a revolving vacuum furnace with an inlet transfer lock for introducing a batch of workpieces into the revolving vacuum furnace and with an outlet transfer lock for removing the batch of workpieces from the revolving vacuum furnace. The revolving vacuum furnace has also an annular turntable for transporting the batch of workpieces from the inlet transfer lock to the outlet transfer lock. At least one carburization furnace, for carburization treatment of the batch of workpieces, is connected to the revolving vacuum furnace at least at a peripheral location of the revolving vacuum furnace between the inlet transfer lock and the outlet transfer lock in the direction of transportation of the batch of workpieces. The annular turntable transports the batch of workpieces to the at least one carburization furnace.

Abstract: For quenching heated metallic work pieces with a quenching intensity that lies in the region of H values from 0.2 to 4, which is typical for oil or water quenching, a cooling gas is used as the quenching medium in the form of discrete jet streams issuing from a nozzle field and impinging on the work piece surface to be cooled. With limiting of the blower power for the cooling gas serving a predetermined maximum limit of about 1000 kW per square meter of nozzle field the quenching intensity, with suitable selection of gas jet parameters, in particular the gas velocity w, the gas pressure p, the gas jet cross-section and the number of impinging jets per unit of surface is brought to an H value between 0.2 and 4.

Abstract: An apparatus is disclosed, which serves to contact with a flowing gas two mutually opposite, substantially flat and substantially circular annular surfaces of an annular cylindrical workpiece having an inside diameter not in excess of a predetermined maximum inside diameter. The apparatus comprises an oven housing, which contains two mutually opposite plenum chambers, which are defined by respective side walls which are spaced apart in an axial direction and define between them an oven chamber adapted to accommodate said workpiece in a position in which each of said side walls faces one of said surfaces of said workpiece, each of said side walls being formed with orifice slot means, and a fan for supplying a gas to said plenum chambers.

Abstract: A pressure pad comprises a plenum chamber, adapted to be conneceted to a pressurized-fluid supply means, having a pair of parallel slit nozzles formed in a top wall, and the chamber is arranged underneath a path of a strip. The plenum chamber is provided with holes in the top wall and at least two obstructions on the top wall. The holes are arranged on imaginary lines that extend between the nozzles on both sides of the top wall and central portions thereof point to adjacent edges of the path. Each of the obstructions comprises at least one obstructing wall arranged on either side of one of the imaginary lines. The lines may have V-, Arch- or Bracket-shaped configurations.

Abstract: A gas diffusing nozzle device for a fluidized bed furnace having high thermal resistance and durability especially, in a high-temperature environment and capable of being manufactured at a low cost, fluidizing a fluid layer uniformly using a fluidized gas jet with a low pressure loss and controlling the flow rate of the fluidized gas jet at the outer circumferential and central portions of the interior of a retort (11) in an arbitrary and individual manner. This device is provided with a circumferential gas supply pipe (19), a central gas supply pipe (24), and a circumferential gas diffusing nozzle section (14) and a central gas diffusing nozzle section (15) respectively connected to these two gas supply pipes. Each of the gas diffusing nozzle sections has a plurality of nozzle pipes (16b, 22) with a plurality of downwardly directed fluid gas ejection ports (17) formed in the lower surfaces thereof, and at least one ring-shaped nozzle pipe (16a, 21) joined to the free ends of these nozzle pipes.

Abstract: Method and apparatus for densifying an article wherein the article is disposed in a first molten salt pressure transmission medium in a container. The first medium is heated to a first elevated densifying temperature. The container is disposed in a second molten salt pressure transmission medium at a second temperature lower than the first temperature. The first medium and the second medium are communicated so that pressure applied to the second medium is transmitted to the first medium. Pressure is applied to the lower temperature second medium sufficient to densify the article disposed in the first higher temperature medium. Following densification of the article, the container is removed from the second medium. The method and apparatus are especially useful for closing internal porosity of metallic and intermetallic castings.

Abstract: A gas-carburizing process wherein an article is treated by feeding a hydrocarbon gas and an oxidative gas of raw material gases directly into an atmospheric heat treating furnace, characterized in that, when the pressure within the furnace is negative, CO.sub.2 is fed as a negative pressure dissolving means.A gas-carburizing apparatus wherein a gas inlet for feeding a hydrocarbon gas and an oxidative gas provided in the ceiling part of an atmospheric heat treating furnace is provided with a CO.sub.2 feeding part for dissolving the negative pressure within the furnace.

Abstract: Apparatus suitable for annealing the interior walls of a nuclear reactor which comprises a nuclear reactor shell, a cap securely attached to the nuclear reactor shell, wherein the cap has an inlet line for the introduction of a hot gas under high pressure and an outlet line for removing low pressure gas from the interior of the apparatus, means, such as a cylindrical shell, that helps define an annular space adjacent to the vertical walls of the reactor through which gas can flow and means for directing low pressure gas to the outlet line.

Abstract: A rotary oil seal gas purge system for a rotary carburizing furnace, having a rotatable hearth in a furnace chamber containing a high carbon-potential furnace atmosphere comprising an endothermic carrier gas enriched with a hydrocarbon gas, features gas purge ports located adjacent to the oil seal(s) of the hearth for injecting non-carbon-enriched endothermic gas to purge the high carbon-potential furnace atmosphere from the area adjacent the seal(s) and prevent carbon precipitation into the seal(s). Also disclosed is an oil seal management system for a rotary carburizing furnace including a settling tank for accepting seal oil from the furnace oil seal(s), a pump supply tank for receiving oil from the settling tank, a pump for pumping oil from the pump supply tank through a heat exchanger and to the furnace oil seal(s), and a centrifuge for cleaning seal oil coming from the heat exchanger before returning it to the pump supply tank.

Abstract: Process for heat treating articles by hardening them in a recirculating gas medium which is in contact with the treated articles, the hardening gas being cooled by means of a heat exchanger, of the type in which helium is used as hardening gas, and is stored under holding pressure in a buffer container, wherein at the end of a hardening operation, a helium load is extracted from the treatment enclosure, in final phase by means of pump until a primary vacuum is obtained, the extracted helium is brought to purifying pressure by means of a compressor associated to a mechanical filter, and the helium under purifying pressure is sent to a purifier in which impurities are removed, after which it is transferred, if desired, after recompression in the buffer container.

Abstract: A fluidized bed is disclosed for the continuous quenching of steel wires. The fluidized bed is provided with an air convection cooler with high cooling capacity. The temperature of the fluidized bed is regulated by means of a cooling air flow. Such a bed is applicable in the patenting operation, in which the carrying gas for a fluidized bed is taken from the exhaust gases of the austenitizing furnace.

Abstract: The present arrangement provides for having the plenum divided into at least two sections. One section dumps quench gas from a first direction into the hot zone chamber during a first period and the other section dumps quench gas into the hot zone from an opposite direction during a second period whereby the cooling is relatively uniform. During the quenching operation the quenching gas is drawn from the hot zone chamber through a heat exchange and is returned therefrom to a loop through the hot zone chamber in touch with the workpiece. Direction flow gates control the alternate use of the two plenum.

Abstract: A method and device (100) for heat treating a metal strap (1), characteri by passing the strap (1) within an enclosure (2) containing a gas (3) which is practically free of forced ventilation, in such a manner that a transfer of heat takes place between the strap (1) and the walls (2a) of the enclosure (2) by means of the gas (3) contained in the enclosure (2). Metal straps (1) obtained by this method and this device (100).

Abstract: A sintering furnace includes an upper housing having a gas permeable insulating enclosure therein, with heating elements within the enclosure, and a lower housing having a hearth against which the insulating enclosure rests. Sweep gas is introduced to the interior of the upper housing, outside of the insulating enclosure. The sweep gas flows through the porous enclosure, past the pieces being sintered to sweep organics away, and out of the enclosure through an organics sink post extending upwardly from the hearth. The sink post is hollow and has openings therein, and is in communication with an external trap and vacuum pump, so that the organic-laden sweep gas is drawn out of the furnace. The insulating enclosure includes a gas barrier having openings therethrough and insulation layers on either side, the openings being sized such that the flow of sweep gas prevents diffusion of organic vapor out of the enclosure into the upper housing.

Abstract: A vertical heat treatment apparatus includes a reaction furnace constituted by a reaction chamber having an inner tube and an outer tube and a heater arranged outside the reaction chamber, a manifold communicating with a lower portion of the reaction chamber to support the reaction chamber and a gas being supplied and exhausted through the mainfold, a hollow vessel, arranged together with the boat in the reaction furnace, for supporting a lower end of a boat having objects, and a plurality of first heat-insulating members detachably arranged in the hollow vessel, wherein the number of the first insulating members is adjusted to adjust a heat-insulating effect. The first heat-insulating member includes a fin unit constituted by fins horizontally arranged at predetermined intervals and spacers for keeping the intervals between the fins.

Abstract: The invention is exclusively concerned with heat treatments before hardening, of metallic pieces, by cementation, carbonitridation and heating. The process concerns the feeding of a non muffle heat treatment furnace with various components including nitrogen which is produced by an adsorption or selective permeation generator and which has a residual oxygen content of the order of 2%. According to the invention, after the furnace has ceased to be in operation for a substantial period of time, it is reconditioned by injecting purer nitrogen which has a residual oxygen content lower than 0.3% and which is produced by said generator, adjusted at a lower extraction rate.

Abstract: A heating mantle for heating materials, such as metals, alloys or inorganic chemicals in a retort, includes a tubular wall and annular chambers cooperating with said wall for forming a tortious path around the retort for hot gases. The mantle provides a very high convective heat transfer coefficient.

Abstract: In a gas carburizing method, a hydrocarbon gas and air are supplied to a furnace main body that carburizes a workpiece. The hydrocarbon gas and air react with one another in the furnace main body to generate an atmospheric gas having a carburizing property. The flow rate of the hydrocarbon gas to be supplied is maintained at a predetermined value. The flow rate of air to be supplied can be altered by adjusting the carbon potential of the atmospheric gas.A gas carburizing apparatus includes a furnace main body and load and unload chambers provided on two ends of the furnace main body. The load and unload chambers have combustion units. The combustion units communicate with the interiors of the load and unload chambers and burn a hydrocarbon gas. The combustion gas of the hydrocarbon gas is supplied to the load and unload chambers.

Abstract: Air quenching apparatus develops a pearlite microstructure in the head of a longitudinally travelling railroad rail as it travels under the apparatus. A primary air chamber at a controlled pressure provides air to the top and side surfaces of the rail heads. A secondary air chamber at a separately controlled pressure provides air to the shoulders of the rail heads. More than one quench unit may be used in series, in which case the pressures in the primary air chambers may progressively increase to increase the cooling rate.

Abstract: A method of and an apparatus for controlling a quantity of an explosive gas mixture to be used in treating workpieces with thermal and pressure shocks wherein a signal gas having a predetermined initial pressure is introduced into a workpiece treatment chamber of the apparatus for determining a volume of workpiece loaded into the treatment chamber by a pressure difference between the predetermined initial pressure of the signal gas and a filling pressure thereof, which pressure difference is representative of the volume of the workpieces in the treatment chamber, and metering of the explosive gas mixture is effected in accordance with this pressure difference.

Abstract: Known techniques of plasma case hardening of workpieces may fail to provide sufficient treatment to re-entrant portions, such as fine holes, in the workpiece. This specification discloses a technique of pulsed plasma treatment in which the duration of the plasma pulses and the intervals between them are selected to allow a substantially even distribution of the gas which forms the plasma over all the surface to be treated of the workpiece.

Abstract: A system for cooling non-ferrous metal dross comprises an open-top metal pan to receive the dross which pan is divided by internal partitions into open-top compartments and has sufficient heat capacity to act as a heat sink to absorb heat from the dross, and a hood shaped to fit over the pan when filled with dross to form a substantially closed cavity round the pan. An inert gas such as argon is introduced into this cavity to displace oxygen and reduce the extent of oxidation of residual metal in the dross.

Abstract: An apparatus for deburring workpieces by gas detonation comprises a bed (1) having mounted thereon a casing (2) open at one end (4), and an indexing table (6) with bottoms (7) arranged alternately in front of the open end (4) of the casing (2). There is also provided a drive (9) for moving the bottom (7) toward the open end (4) of the casing (2) to form during their connection a gas detonation chamber (10), and a system (13) for feeding gases thereto for forming an explosive mixture with a spark plug (15). Connection of the casing (2) to the bottom (7) is done by a bayonet joint (16) one element of which is kinematically linked with a drive (17) for turning it relative to the other element.

Abstract: Fluidized bed apparatus 1 for use in heat treating metal articles in a bed of fluidized particles 6 includes a heat insulated structure 2 and a removable module 4. The module is a metallic assembly integrating a vessel 5 for receiving the fluidizable particles, a bottom plate 8 of the vessel having a plurality of gas inlet nozzles 9, and a gas plenum chamber 11 fed by a gas admission conduit comprising a gas duct 12 and an entry pipe 13. Each nozzle 9 comprises a vertical inlet pipe 25 and a distinct cap 26 of specific channel design mounted on top of the pipe for deflecting a fluidizing gas flow into the particle bed 6.

Abstract: A device for the uniform application of gas on a plane surface comprises several slot-like openings which are at least approximately in one plane; the longitudinal axes of the nozzle openings are radially arranged, whereas the direction of the flow exiting from the slot-like openings is inclined towards the plane in which the openings are located. This allows an extremely uniform application so that the difference between the maximum and the minimum values of the heat-transfer coefficient is only very small.

Abstract: Heat treating apparatus in which a diffuser mounted beneath a bed of sand in a heating chamber passes gas through the sand to fluidize it. In one form of the invention, the gas rises through slits coined in a metal plate that supports the sand. In another embodiment of the invention, the gas rises through ceramic fiber mesh which uniformly fluidizes the sand.

Abstract: The present invention relates to a method and apparatus for preparing metal-embedded porous metallic-hydride (pmh) compacts capable of with standing repeated hydriding-dehydriding cycles without disintegrating. According to the invention, the finely divided hydridable metal alloy hydride is admixed with a finely divided metal selected from Al, Ni, Cu or other transition metals and charged with hydrogen. The resulting mixture is sintered in a furnace in which hydrogen is introduced at a pressure above the equilibrium pressure to the prevailing temperature, mechanical stress being applied simultaneously. The compacts obtained possess outstanding stability, as shown by the fact that they have remained intact even after more than 6000 cycles.

Abstract: A device is suggested wherein the work piece finishing chamber (31) serves simultaneously as a mixing chamber for mixing the gas components, and wherein a gas deceleration stage (47) is integrated in chamber block (30) between chamber (31) and a spark plug (54). The gas deceleration stage (47) is provided with labyrinth like extending bores (49,50,51). The combustion residues generated in the work piece finishing chamber (31) cannot reach spark plug (54) in view of the gas deceleration stage (47). Thus, a contamination of the spark plug (54) being disposed in block (30) is substantially eliminated.

Abstract: A process for ion nitriding of aluminum or an aluminum alloy and an apparatus therefor, wherein aluminum or an aluminum alloy as an article to be treated is disposed on a substrate holder provided in a sealed container. A predetermined metal having an intensive affinity for oxygen is also disposed in the vicinity of the article to be treated, and a glow discharge is operated between an electrode provided in the sealed container as an anode and the substrate holder as a cathode. The electrode may be directly provided at the sealed container itself or it may be independently provided therein. According to the process and apparatus of the present invention, it is possible to form on the surface of aluminum or an aluminum alloy an aluminum nitride layer having an intensive adhesion to a substrate thereof, high hardness and excellent wear resistance.

Abstract: An automatic control for a multi-zone push type carburizing furnace capable of controlling the flow of either an endothermic gas atmosphere or a nitrogen methanol atmosphere at both high and low flow rates and during normal and suspend carburizing utilizes cascaded multi-stage valving to assure good separation of the atmospheres in adjacent zones. The first stage of the cascaded multi-stage valving controls the total gas flow, and the second stage routes the gas to individual zones of the furnace.