Abstract: An integrated continuous/batch furnace system for heat treating metal parts combines a continuous furnace system and a batch furnace system. The continuous furnace system includes a preheat furnace, a rotary carburizing furnace, an equalize/diffusion furnace, an oil quench, a press quench chamber and a slow cooling chamber. The batch furnace system includes a temper furnace, a carburize/quench/slow cool furnace, and a washer. A parts tray system for holding parts to be heat treated includes a parts tray for transporting parts through the continuous furnace system, and a parts tray assembly for transporting parts through the batch furnace system. The parts tray assembly includes two parts trays detachably coupled together with rigid U-shaped alloy chips.A method for heat treating trays of parts in an integrated continuous/batch furnace system includes determining whether to heat treat the parts with the continuous furnace system or the batch furnace system.

Abstract: A metal tube induction annealing apparatus employs an induction heating enclosure having an elongated glass tube encircled by an electromagnetic coil of an induction heating system which provides an induction annealing chamber for receiving a hollow metal tube for undergoing annealing and an inert purge gas for bathing the tube during annealing. Cooling stages are located end-to-end downstream of the induction enclosure for progressively cooling the annealed tube. The inert purge gas is made to flow upstream in a direction opposite to the downstream direction of tube movement through the annealing chamber and cooling stages for accomplishing constant bathing or shielding of the exterior and interior wall surfaces of the tube and removal of heat by inert purge gas flowing through and out of the trailing end of the tube.

Abstract: This invention relates to a method of nitriding steel material in a second heat treatment furnace after fluorinating the steel material in a first heat treat furnace to form a deep and uniform nitrided layer. Then, steel material is treated smoothly by defining the ratio of establishing said both furnaces for fluorinating and nitriding on the basis of treating time required for said both treatments since time required for each treatment is different.

Abstract: A refractory hearth for use in an industrial heat treat furnace is disclosed whereby the hearth contains no alloy parts with the exception of the pusher assembly and the roller chain attached to it. L-shaped ceramic, refractory or silicon carbide tile are placed in position to support material being heat treated, while at the same time preventing the roller chain from rising up out of place. The outside edges of said L-shaped tile shall act as guides to move stock trays in a straight path. Refractory material used to hold hearth in place will also support radiant tubes used to supply heat.

Abstract: An endothermic furnace for sintering metal includes a pair of U-shaped retort tubes which are mounted to the underside of a flat, rectangular lid, the lid being removably secured along the respective top vertical edges of the furnace chamber sidewalls and the retorts being removable with the lid. Each tube carries a catalyst and receives a carbonaceous gas mixture that is either combusted externally or internally of the chamber, the gas reacting with the catalyst to produce a desired endothermic gas product which heats each tube whereby to radiantly heat the chamber and which is piped back into the heat chamber, when cooled, to provide an oxygen-free atmosphere for the heat treating chamber.

Abstract: An annealing treatment in a continuous furnace in which a flow of dense inert gas is injected in a rising duct and a descending duct, these flows being regulated by the analysis of hydrogen detected by a pressure controller acting on valves to achieve a minimum escape of hydrogen.

Abstract: A furnace for the formation of a black oxide film on the surface of a thin metal sheet is disclosed which comprises a tunnel-like furnace proper provided at one terminal side thereof with an inlet and at the other terminal side thereof with an outlet, conveying means laid inside the furnace proper from the inlet through the outlet thereof for conveying a thin metal sheet from the inlet to the outlet, openable shutter means for partitioning the interior of the furnace proper into at least first and second regions on the front and rear sides respectively in the direction of conveyance of the thin metal sheet, first gas supply means for feeding into the first region on the inlet side of the furnace proper partitioned by the shutter means a mixed gas containing carbon dioxide and carbon monoxide and containing substantially no oxygen or a mixed gas containing carbon dioxide, carbon monoxide, and steam and containing substantially no oxygen, second gas supply means for feeding into the second region on the outlet

Abstract: A cooling device for a high pressure vessel which is simple in construction and high in safety and has a high cooling faculty without the necessity of changing a design of the high pressure vessel. The cooling device has a cylindrical cooling medium jacket having a cooling medium passage formed therein. The cooling medium jacket is removably disposed in a high pressure chamber of the high pressure vessel between the high pressure vessel and an insulation mantle surrounding a heater in the high pressure chamber such that a gap may be left between the high pressure vessel and the cooling medium jacket. The cooling medium jacket has a passage hole formed therein for establishing communication between the gap and the high pressure chamber to allow pressure medium to be introduced into the gap.

Abstract: An enclosure or housing for a furnace structure or the like such as for a reheat furnace of the type used in steel rolling operations, the furnace enclosure being comprised of a self-supporting arch structure preferably of sheet material such as steel and having thermal insulation extending continuously over the inner or concave expanse thereof, the arch structure forming an elongated, arched furnace enclosure which provides improved thermal energy distribution, simplified design, and enhanced overall economy.

Abstract: A high pressure sintering furnace is disclosed for the production of compacts from metal and/or nonmetal powders. By mounting a cooling device between the wall of the high pressure shell and the thermal insulation, relatively thin walls can be used for the high pressure shell. Shorter cooling times are also obtained.

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: Metal strip in coils is heat-treated by impinging jets of a temperature-controlled gaseous medium on the ends of the coils which are positioned with the coil axis horizontal. The medium is recirculated through heat exchangers. A rotating hearth furnace for such heat-treating has an annular hearth which carries coils in intermittent movement through successive stations in which the gaseous medium is directed on the coils.

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 method of gas carburizing and hardening a steel article and a continuous furnace therefor. The method includes the steps of carburizing the article in a carburizing atmosphere at atmospheric pressure, heating the article in a vacuum for a predetermined period of time, and hardening the article.

Abstract: A nitride layer is formed on the surface of a shaped article of titanium by a method which comprises bringing nitrogen gas into contact with the shaped article of titanium in a heated state. The nitrogen gas, en route to the site of contact with the shaped article of titanium, is preparatorily caused to come into contact and react with small particles of titanium so as to be deprived of such extraneous components as hydrogen and oxygen and consequently converted into pure nitrogen gas. This pure nitrogen gas is introduced into contact with the shaped article of titanium in a heated state to effect the nitriding of the surface of the shaped article. An apparatus to be used in effecting the nitriding treatment by the method of this invention is also disclosed.

Abstract: A continuous carburizing furnace system is disclosed having at least two series-connected rotary furnaces. The rotary carburizing furnace, a rotary equalizing furnace, and a rotary diffusion furnace which may be included between the carburizing and equalizing furnaces, allow trays of parts to be discharged from any position at any time by suitable rotation of their hearths, thus allowing parts with different cycle times to be run simultaneously in each rotary furnace. Each donut-shaped rotary furnace includes one or more captive chain type pusher mechanisms mounted in vertical fashion within a central area or hole, and the rotary carburizing furnace is multi-zoned and includes wall-mounted fans for uniform circumferential control of the gaseous atmosphere within its annular chambers.

Abstract: Fluidized-bed type carburizing furnace means of the class provided with a path for circulation of the furnace gas of a fluidized-bed type carburizing furnace is improved by incorporation therein of ejector means for spouting compressed gas into the circulation path. The circulation path comprises an outlet pipe emanating from the furnace gas outlet of the fluidized-bed type carburizing furnace, a cyclone connected through the medium of the outlet pipe to the fluidized-bed type carburizing furnace, and a discharge pipe emanating from the cyclone and joined to the furnace gas inlet of the fluidized-bed type carburizing furnace. The ejector means comprises a constriction formed in the discharge pipe and a feed pipe for compressed gas having the leading end thereof inserted into the constriction.

Abstract: A fluidized bed for treating of product at high temperatures (1100.degree. C. to 1300.degree. C.) is possible, while overcoming problems such as slow start up times and contamination due to combustion gas. The fluidized bed uses an inert gas introduced to the bed to cause fluidization of refractory particles. Exposed surfaces or boundary layers of the bed are heated by infrared radiation produced exterior to the bed and absorbed by exposed particles of the bed. The thermal characteristics of the bed insure rapid dissipation of the absorbed energy. Electrically powered lamps produce the radiation and preferably are high intensity shortwave infrared radiation lamps. The lamps remain out of direct contact with the bed preferrably separated by a quartz wall or screen.

Abstract: A heat treatment apparatus for metals or metal articles has a fluidized-bed furnace for heating the metals and a cooling chamber disposed above the furnace so as to communicate with a heating chamber of the furnace through a partition capable of being opened and closed, so that the metals can be cooled immediately after heated. The apparatus further includes a circulating circuit arrangement with a heat-resisting fan for circulating together or separately heated furnace gas and cooling fluid. Flow rate of the circulating furnace gas and/or cooling fluid is controlled by a flow rate control device provided in the circulating circuit.

Abstract: A method and vacuum furnace for heat-treating a charge. Pursuant to the method, after the charge is placed in the receiving vessel, the latter is evacuated and flooded with inert gas. Subsequently, the charge is heated to the maximum permissible operating temperature of the circulation device by heating and gas circulation. Thereafter, the charge is heated to the desired end temperature by static inert gas or under vacuum, and essentially by radiation heat. The vacuum furnace may include a steel vessel which can be closed off, and which contains an inner heating chamber for receiving the charge. A heating device is provided within the heating chamber, and a fan and a gas guiding arrangement are provided for producing a gas circulation through the heating chamber. In the second phase, in which the heating is effected by radiant heat, the heating chamber can be closed off, accompanied by disconnection of the fan. For this purpose, an opening is provided in the wall of the heating chamber.

Abstract: This application discloses a method and apparatus for conducting various metal treatment processes including nitriding, carbonitriding, nitrocarburizing, surface activation, and selective oxidation in any desired sequence in the same fluidized bed furnace. The apparatus comprises a fluidized bed furnace having a humidifier system including a humidifier and superheater and the method involves exposing a metal workpiece sequentially to at least two separate metal treatment atmospheres in a fluidized bed furnace.

Abstract: A furnace for heat-treating light alloy ingots comprises a heating chamber, which is flown through by hot gases and communicates with a stock inlet and with a stock outlet and contains between said stock inlet and outlet a conveyor for intermittently conveying the ingots, which lie on said conveyor and extend transversely to its direction of conveyance. The intermittent conveyor is accommodated in a heating shaft and consists of at least two juxtaposed vertical conveyor sections, which convey in mutually opposite directions and are interconnected by transfer means. A partition which divides the furnace shaft is provided between that conveyor section which is adjacent to the stock inlet and the next following conveyor section.

Abstract: The invention provides a method and apparatus for producing a regulated atmosphere in a heat treating furnace. In the preferred embodiment, liquid methanol is heated sufficiently to cause it to dissociate into hydrogen and carbon monoxide, i.e. the combustible components. These dissociated combustible components are then mixed with a relatively inert gas such as nitrogen. This mixture of combustibles and non-combustibles forms the atmosphere for the furnace. The proportion of one or more combustibles in the mixture is measured, and the flow of the inert gas into the mixer is regulated so as to maintain precisely the desired ratio of combustibles to non-combustibles in the furnace atmosphere. The invention includes various mechanisms for preventing unsafe temperature and pressure conditions, and for insuring that unwanted byproducts of dissociated methanol are not created.

Abstract: A hot isostatic pressing apparatus having a high pressure vessel, a heat insulating layer and a heater disposed inside the heat insulating layer, the heat insulating layer and the heater being disposed within a high pressure chamber defined by upper and lower covers. The heat insulating layer is composed of at least two inner and outer inverted cup-like casings, the outer casing being metallic and having a hermetic structure and the inner casing having a hermetic structure. A passage is formed in the upper surface of the outer casing and a valve capable of being opened and closed is provided therein. Further, a mechanism for opening and closing the valve is mounted on the upper cover, and a gas passage is formed in the lower portion of the het insulating layer. The above arrangement creates a convection of gas in the cooling step after the HIP treatment whereby a remarkable improvement can be attained in cooling efficiency, cooling time and productivity.

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: For recovery of heat, aggregates of metallic articles through which gas can flow are carried in a succession of baskets through a preheat zone, a treatment zone and a cooling zone of a heat treatment furnace and a heat transfer gas is constrained to flow vertically through the baskets in succession, beginning with the basket farthest advanced through the furnace, so far as concerns the basket in the cooling and preheat zone, the baskets having bottoms through which the gas can flow into or out of the aggregates. The heat transfer gas flows directly from the cooling zone. This may be done through the treatment zone where it may pick up additional heat. Heat may be removed from the heat transfer gas in a return circulation path outside the furnace.

Abstract: A combination sintering-annealing furnace is provided, wherein the sintering furnace section and the annealing furnace section are arranged adjacent with each other and separated by a partition wall. A plurality of ventilation windows is provided through the partition wall to allow the waste combustion gas in the sintering furnace to flow into the annealing furnace. The opening area of each ventilation window is adjusted by an adjuster plate. The annealing furnace is also provided with a plurality of cold air inlet ports for introducing therethrough cold air from the atmosphere, the opening area of each cold air inlet port being adjusted by an adjuster plate. A desired temperature distribution in the annealing furnace may be established by controlling the opening areas of the respective ventilation windows and respective cold air inlet ports.

Abstract: A rotary hearth finish annealing furnace includes coil tables carrying thereon steel plate coils to be annealed with their axes being vertical, a hearth traveling along a circle having a predetermined radius and supporting thereabove the coil tables, inner covers covering the coils on the coil tables, and a protective cover covering the above members over a predetermined distance.According to the invention, heating means for heating the coils are arranged at a level above upper ends of the steel plate coils. In a preferred embodiment, the coil tables are arranged so as to permit the coils to be arranged thereon in at least two circular rows on a single plane concentric to said traveling circle of the hearth. Moreover, portions of the hearth subjected to loads of the coils and coil tables are made of comparatively high strength bricks and the other portions are made of a light weight refractory material.

Abstract: The present invention involves an apparatus and method for heat treating metal workpieces in chemically controlled environments produced by decomposition of an atmosphere precursor, e.g. methanol or ethyl acetate, introduced to a heated fluidized bed retort as a vapor.

Abstract: A hot isostatic pressing apparatus equipped with a pressure vessel, a heat-insulating layer provided within the pressure vessel and a heating unit disposed inside the heat-insulating layer, in which the heating unit is formed of a cylindrical, self-standing and single-stage heater mounted on an electrical insulator, which is in turn provided in a low-temperature zone of the pressure vessel, and a convection-promoting cylinder provided inside the heater with its lower part supported on the electrical insulator, wherein the upper extremity of the convection-promoting cylinder is located above the upper extremity of the heater, and the convection-promoting cylinder defines a gas flow passage in the lower part thereof. Owing to the provision of the convection-promoting cylinder, the effective height of the uniform temperature zone, namely, the treatment spacing in the pressure vessel is increased by 1.5-3.

Abstract: A hot isostatic pressing apparatus which includes a pressure vessel, a heater and a heat-insulating layer interposed between the pressure vessel and heater. The heat-insulating layer is formed of at least two layers, i.e., an inner layer and outer layer. The inner layer embraces an object, which is under treatment, and the heater. The inner layer is loadable in and unloadable from the pressure vessel together with the object and heater while maintaining a space, which is embraced by the inner layer, in a state hermetically isolated from the surrounding atmosphere. However, the outer layer is held within the pressure vessel. When the hot isostatic pressing apparatus is incorporated in a modular HIP system, the cooling time is considerably shortened and the efficiency of the HIP treatment is hence improved to a considerable extent.

Abstract: A furnace system is described having a rotatable table with five stations, a loading station, a preheating station, a heating station, a cooling station and an unloading station. A furnace having three compartments, a preheating compartment, a heating compartment and a cooling compartment is vertically movable so that a steel charge to be annealed located on the rotatable table may be moved from one station to another when the furnace is lifted out of contact with the table. Air ducts are provided to transfer heated air from the cooling station to the preheating station. The system is very efficient for, when one charge is cooling a succeeding charge is being heated while the next succeeding charge is being preheated. At the same time a charge can be loaded and another charge can be unloaded. Thus, five steps of an annealing cycle can be accomplished simultaneously allowing an annealed charge to be completely cycled during each step.

Abstract: A HIP system of the type which includes a high pressure vessel with top and bottom plugs for closing top and bottom open ends thereof or a high pressure vessel closed at one end and having a plug for closing the other open end thereof, and a high pressure and temperature processing chamber defined in the pressure vessel and having a heat insulating mantle and a heater disposed around the inner periphery thereof for subjecting a workpiece supported on the plug to sintering or other treatment in a high pressure and temperature gas atmosphere, the HIP system including: a removable shield casing hermetically engageable with the workpiece supporting plug and adapted to be loaded into and unloaded from the high pressure vessel along with the workpiece, holding the processing chamber in a sealed state; and a valve member provided in the shield casing for selectively establishing and blocking communication of the processing chamber with an exterior atmosphere such that the processing chamber is selectively placed in

Abstract: A metal heating furnace for heating slabs, billets or blooms prior to their hot rolling. Full use to thermal energy can be ensured and the workpieces can be uniformly heated to a desired rolling temperature.

Abstract: A furnace for heating steel articles and so on without oxidation and decarbonization. In the furnace, non-oxidation gas atmosphere with or without cementation characteristics is produced and regenerated by subjecting the air to carbon elements and heat at a reaction chamber provided within the furnace or closely thereto, and the gas atmosphere is circulated through a substantially closed circuit with the said reaction chamber connecting outtake and intake openings of the furnace.

Abstract: A continuous electric furnace for chemical heat treatment of steel parts comprises a parts heating chamber, a parts vertical supply chamber and a cooling chamber, all arranged in line. The parts vertical supply chamber is connected to a processing chamber wherein a hearth is equipped with a vacuum seal serving to separate the processing chamber from the other chambers in the process of chemical heat treatment of parts. The heating and cooling chambers comprise extension stops and heat screens located on the side of the parts vertical supply chamber, and the hearths movable reciprocally in a horizontal direction.

Abstract: A semi-continuous vacuum heat-treating furnace of two-chambers and one-door type is composed of a vacuum heating chamber which includes a heating element and a heat insulation material, both being stable in chemical property and strength in vacuum condition and atmospheric pressure at high temperature, a cooling chamber which is associated with the vacuum heating chamber, and an intermediate vacuum door which separates the vacuum heating chamber and the cooling chamber from each other.

Abstract: In the walking beam furnaces, in order to heat metallurgical materials such as billets, bars and the like, having different temperatures of introduction into the furnace and/or different cross sections, so as to discharge materials at uniform temperatures from the furance, said materials are selected according to their temperature and/or cross section, and are introduced into the furnace through a plurality of side inlet doors while said materials are conveyed along the furnace by means of an external side conveyor, and/or they are discharged from the furnace through a plurality of side outlet doors and are then advanced outside along the furnace by means of an external side conveyor.

Abstract: An apparatus and method for removing burrs and other roughage from stamped, milled and cast metallic articles. A conical combustion chamber is provided with a spiral groove which creates a turbulent flow for an ignited combustible mixture, which turbulence transforms the process from combustion to detonation. The detonated gaseous mixture is directed down the conical combustion chamber in expanding fashion to the articles which are to be de-burred, which articles are stored in a receptacle in axial alignment with the conical-shaped combustion chamber. During detonation, the burrs and other roughage are removed from the articles, while the remainder of each article is kept in tact.

Abstract: A method of operating a continuous heat treatment furnace for metal strip coils includes steps of enclosing them in muffles in the furnace supplied with an atmosphere gas containing a combustible gas such as hydrogen and feeding the muffles into and through the furnace having therein heating, soaking and cooling zones. According to the disclosed method, at least part of the heating and soaking zones is heated by direct firing heating with a fluid fuel with excess air and combustible gas leaked from the muffles into the furnace is burnt in the furnace with the aid of the excess air. Combustible gas leaked from the muffles into the cooling zone is diluted with air forced into the cooling zone to make the combustible gas incombustible and thereafter to exhaust it out of the furnace, thereby eliminating ignition means for the combustible gas in the furnace and particular precaution for preventing an ignition failure.

Abstract: In a method for continuous heat treatment of separated elongated metallic material said material is conveyed stepwise through a single furnace chamber. Said furnace chamber comprises a heating section and an adjacent holding section. In the heating section the material is heated up to a treating temperature and in the holding section the material is held at the treating temperature both in an atmosphere of forced circulation of hot gas common to both furnace sections. The temperature of the circulated hot gas is automatically feedback-controlled at the location of the transition between the heating section and the holding section, the hot gas being set into forced motion in a single circulating zone and being heated up in a single heating zone with respect to the direction of passage of the material.

Abstract: The present invention relates to a sintering furnace for powder metallurgy of cemented carbides, cermets and ceramics, which comprises a main furnace body, a heating chamber provided in the main body, a table having a moving means for carrying a workpiece in or out of the heating chamber and a means for cooling the interior of the furnace with a heat exchanger fitted to the exterior of the main furnace body, and a method for the sintering and heat treatment of cemented carbides in the sintering furnace as claimed in claim 1, which comprises sintering cemented carbides and cooling rapidly at a cooling rate of at least 30.degree. C./min from the sintering temperature being at least a temperature at which a liquid phase appears to at most 1000.degree. C. by the use of an inert gas as a coolant.

Abstract: Workpieces are heat treated in a fluidized bed contained within a vessel having a central well surrounded by helical ramps along which the workpieces move into and out of the bed. A perforated platform connects the ramp and movement of the workpieces along the discharge ramp is achieved by vibrating such ramp.

Abstract: A scale-covered, hot-rolled steel work is heated under a reducing atmosphere and is then allowed to slowly cool while placed under the reducing atmosphere. Thereafter the work is maintained at a predetermined temperature under an oxidizing atmosphere to cause the scale to be re-oxidized. The work with the re-oxidizing scale is then allowed to stand to cool quickly, imparting fine cracks to the scales. The scales can readily be removed from the work during the subsequent pickling step.

Abstract: An apparatus for the treatment of a metallic workpiece includes (a) a transport structure which includes a mounting portion and a platform portion, the platform portion, which is the part of the transport structure on which the workpiece to be treated is positioned, being electrically insulated from the mounting portion, and (b) a hollow furnace which includes heating elements and two spaced apart electrodes, the furnace being constructed to allow the platform portion of the transport structure to be located within the hollow furnace during its operation while the mounting portion remains exterior thereto.

Abstract: Metal is melted in melting vessels heated in a melting furnace by combustion of fuel and by exhaust gases from the combustion. In order to prevent evaporation, overheating and contamination of the melt, the exhaust gases of the melting furnace, including unburned fuel components of the exhaust gases, are directed through a channel of limited cross-sectional size into a melting chamber of substantially larger cross-sectional size. The hot gases are directed against the surface of melting vessels in the furnace and are allowed to expand in the melting chamber to transfer heat to melting vessels there. In addition, the hot gases are retained and the unburned components are burned in the melting chamber so that their heat capacity is given off to objects within the melting chamber to be stored in those objects to achieve a high degree of utilization of the fuel.

Abstract: Heat-treating apparatus which includes an insulated furnace compartment through which stock to be heat-treated is passed. Perforated tubes are arranged in the furnace and they are heated to radiance by burners which also generate products of combustion which are ejected through the perforations at high velocity to impinge upon a surface or surfaces of the stock being heat-treated. The combination of radiation and convection enhanced by the impingement of the jets upon a surface of the stock provides highly efficient primary heat transfer. The burners are designed to insure that rapid combustion takes place at a point removed from the perforations to avoid flame issuing from the perforations. The tubes are sized and spaced to enhance secondary heat transfer from gases in the furnace compartment and from the walls of the compartment to the stock.

Abstract: Apparatus for heat treatment of metal pieces such as billets, ingots, bars and the like, by pre-heating using hot gas impingement in a pre-heating furnace, and then transference into a holding furnace using forced hot air circulation where the metal pieces are held for the time required at the desired heat treatment temperature.

Abstract: A steel strip continuous annealing apparatus comprising: a steel strip feeder; a heating-soaking zone for heating and soaking a steel strip at a predetermined temperature; a first cooling zone for rapidly cooling the steel strip at a predetermined cooling rate; a second cooling zone for slowly cooling the steel strip or holding same at a predetermined temperature; a third cooling zone for cooling the steel strip to substantially room temperature; and a steel strip carryout device; wherein the first cooling zone incorporates therein forcible cooling means, the second cooling zone incorporates therein hot-cold change-over means and the third cooling zone incorporates therein forcible cooling means, while said steel strip continuous annealing apparatus further comprises: means for directly bypassing the steel strip from the heating-soaking zone through a first bypass passageway to the second cooling zone; and means for directly bypassing the steel strip from the first cooling zone through a second bypass passage

Abstract: A steel strip continuous annealing furnace comprises a heating zone, a soaking zone and cooling zones, wherein bridle rolls for isolating tension of a steel strip from those in adjacent sections of the steel strip are provided at the inlet and outlet of the furnace and in the furnace so as to define a plurality of tension control blocks and provide tension control mechanisms for controlling the tensions of the steel strip in the respective tension control blocks, so that appropriate tensions can be rendered to the steel strip in the respective zones of the furnace, thereby enabling to secure the safe and satisfactory operating conditions.