Abstract: A furnace working system includes a vacuumed pre-heating zone, a vacuumed gas heating zone disposed behind the pre-heating zone, a vacuumed electric heating zone, a high cooling zone disposed behind the electric heating zone, a low cooling zone disposed behind the high cooling zone, a conveyer disposed in the zones for transporting a work piece through the zones, a pipe couples the high cooling zone to the gas heating zone for supplying a heat from the high cooling zone to the gas heating zone, and a conduit couples the low cooling zone to the pre-heating zone for supplying a heat from the low cooling zone to the pre-heating zone. A transition zone is disposed between the gas heating zone and the electric heating zone.

Abstract: A quench system for applying cooling air to one or more hot metallic components that are supported on a component support having a substantially open construction. The quench system includes a housing having sidewalls that define a cooling chamber with peripheral portions proximate the sidewalls and a center portion spaced inwardly from the sidewalls. The quench system also includes a conveyance system that is configured to carry the component support into the center portion of the cooling chamber, as well as a forced air fan that generates a bulk flow of cooling air through the cooling chamber. The quench system further includes a plurality of nozzle baffles extending inwardly from the plurality of sidewalls to define a narrowing region within the housing between the forced air fan and the conveyance system, whereby, during operation of the fan, cooling air flowing through the peripheral portions of the cooling chamber is redirected into the center portion of the cooling chamber.

Abstract: Provided is a manufacturing method of a hot-rolled steel sheet which enables manufacturing of a hot-rolled steel sheet having excellent surface properties and a fine structure. The manufacturing method of a hot-rolled steel sheet uses a heating device, descaling device, row of finishing mills, cooling device disposed in the row of finishing mills, and rapid cooling device disposed immediately after the row of finishing mills, and the operations of the heating device, cooling device and rapid cooling device are controlled, thereby controlling a temperature T1 of the material to be rolled on an entry side of the row of finishing mills, a temperature T2 of the material to be rolled on an entry side of a final stand in the row of finishing mills, and a temperature T3 of the material to be rolled on an exit side of the rapid cooling device.

Abstract: A method for producing partially hardened steel components in which a blank composed of a hardenable sheet steel is subjected to a temperature increase and shaped into a component; the component is transferred to a tool in which the heated component is cooled and thus quench hardened; during the heating of the blank or component in order to achieve the temperature increase to a temperature required for the hardening in regions that are to have a lower hardness and/or higher ductility, cooling elements are spaced apart from the surface by a small gap; the cooling element is dimensioned so that the thermal energy acting on the region that remains ductile flows through the component into the cooling element, characterized in that in order to space the cooling element apart from the component, micro-nubs or knobs are used, which are distributed over the area of the cooling element.

Abstract: A batch annealing furnace includes a coil support base on which an end face of a coil is mounted and that supports the coil with an axis of the coil being upright, an inner cover that covers an entire body of the coil mounted on the coil support base, and a cooling pipe that extends downward from the upper part of the inner cover to a cavity of the inner peripheral part of the coil mounted on the coil support base and cools the coil from the inner surface side by passing a coolant through the inside of the cooling pipe.

Abstract: A dryer for material to be dried (T), wherein an air supply channel (4) for supplying a drying gas to the drying region is provided, and at least one exhaust-gas opening (8) is provided for removing the drying gas, wherein the air supply channel (4) is surrounded at a distance by an outer wall (11), which has at least one supply opening (12) and at least one removal opening (13) for the cooling medium (K), wherein between the at least one supply opening (12) and the at least one removal opening (13) a flow section (14) for the cooling medium (K) is formed between the outer wall (11) and the air supply channel (4).

Abstract: An induction hardening apparatus and methods are provided. The induction hardening apparatus includes a feed line having first and second ends. A coil assembly is positioned between the first and second ends. The feed line includes a support arrangement for supporting two workpieces against one another and transferring the workpieces simultaneously through the coil assembly along a feed axis defined by the feed line.

Abstract: A furnace for heat treating a metal workpiece is provided. A method and system for processing a workpiece also are provided.

Abstract: A method for forming a part having a dual property microstructure includes the steps of: forming a blank having a narrow top portion and a wide base portion; heating the blank to an elevated temperature; and forming a dual property microstructure in the blank by cooling different portions of the blank at different cooling rates.

Abstract: A method and apparatus for the production of a casting comprises: pouring molten material into a mould for forming the casting; allowing the molten material to solidify; removing the mould at least in part from the resulting solidified casting; and locating the solidified casting in a chamber 10 that completely surrounds and facilitates a controlled rate of cooling of the casting.

Abstract: To provide a technique suitable for elevating strength and toughness of a thin low-carbon steel. By performing rapid heating and rapid cooling to a thin low-carbon steel which is an ordinary steel with a thickness of 1.2 mm or less, a steel where a microstructure becomes a duplex grain size structure mixed with crystal grains having different grain diameters, which is not homogeneous, preferably, hard phase structures are contained in addition to the duplex grain size structure is obtained, and a high-strength and high-toughness thin low-carbon steel is obtained. Further, by performing a heat treatment process involving rapid heating and rapid cooling multiple times, a duplex grain size structure of crystal grains with smaller grain diameters or a hard phase structure contained therein is obtained, so that a thin low-carbon steel with higher strength and higher toughness is obtained.

Abstract: A load transport mechanism for moving a heat treating load in a multi-station heat treating system is disclosed. The transport mechanism has a compact construction that allows it to fit in a centrally located stationary transport chamber. The transport chamber is adapted to provide ready access to multiple treating chambers arrayed around the chamber. The transport mechanism includes a load translation mechanism for moving the load linearly and a load rotation mechanism for rotating the load within the transport chamber. A multi-station heat treating system having a centrally located quenching chamber that includes the load transport mechanism is also disclosed.

Abstract: The present invention provides a rail weld treatment device for improving a resulting microstructure in and around an effected zone of a rail weld and of rails surrounding the rail weld. The device includes, but is not limited to a fixture clamping and centering assembly for engaging a rail head of a rail and a heating and cooling device connected with the fixture clamping and centering assembly to be positioned over the rail head. The fixture clamping and centering assembly comprises an engagement member which removably engages the rail head. The heating and cooling device includes a heating member for heating an effected zone of the rail weld and a cooling member for cooling the effected zone.

Abstract: A method includes preparing a steel slab in which contents of inhibitor components have been reduced, i.e. content of Al: 100 ppm or less, and contents of N, S and Se: 50 ppm, respectively; subjecting the steel slab to hot rolling and then either a single cold rolling process or two or more cold rolling processes interposing intermediate annealing(s) therebetween to obtain a steel sheet having the final sheet thickness; and subjecting the steel sheet to primary recrystallization annealing and then secondary recrystallization annealing. The primary recrystallization annealing includes heating the steel sheet to temperature equal to or higher than 700° C. at a heating rate of at least 150° C./s, cooling the steel sheet to a temperature range of 700° C. or lower, and then heating the steel sheet to soaking temperature at the average heating rate not exceeding 40° C./s in a subsequent heating zone.

Abstract: A method and apparatus for the production of a casting that includes pouring molten material into a mold for forming the casting, allowing the molten material to solidify, removing the mold at least in part from the resulting solidified casting, and locating the solidified casting in a chamber that completely surrounds and facilitates a controlled rate of cooling of the casting.

Abstract: Disclosed are methods, systems and apparatus for manufacturing complex three dimensional open structures by cold forming the component from unhardened metal stock and then selectively heating and quenching the metal to provide the desired strength profile across the component. The metal is initially formed of unheated and unhardened metal through a combination of rolling, stamping and/or milling operations to produce a component having a complex three dimensional open structure. The formed component is then hardened in strategically predetermined areas by sequentially heating and quenching the predetermined areas of the component. The heating and cooling elements are, in turn, provided on at least one robotic apparatus configured for moving the elements across the surface of the component in a manner sufficient to achieve the desired pattern of hardened and unhardened regions across the component.

Abstract: A heat treatment furnace is provided which includes a gas generator with a methanol inlet connected to a methanol feed line and at least one gas outlet for dissociated methanol, wherein said gas generator is disposed to be in heat exchange contact with a cooling zone and a heating zone of the furnace.

Abstract: Provided is a manufacturing method of a hot-rolled steel sheet which enables manufacturing of a hot-rolled steel sheet having excellent surface properties and a fine structure. The manufacturing method of a hot-rolled steel sheet uses a heating device, descaling device, row of finishing mills, cooling device disposed in the row of finishing mills, and rapid cooling device disposed immediately after the row of finishing mills, and the operations of the heating device, cooling device and rapid cooling device are controlled, thereby controlling a temperature T1 of the material to be rolled on an entry side of the row of finishing mills, a temperature T2 of the material to be rolled on an entry side of a final stand in the row of finishing mills, and a temperature T3 of the material to be rolled on an exit side of the rapid cooling device.

Abstract: A furnace for heat treating a metal workpiece is provided. A method and system for processing a workpiece also are provided.

Abstract: A device for implementing a method of sizing a cylindrical part following shaping, by plastic deformation, of a metallic material that has maximum structural shrinkage at a maximum-shrinkage temperature between a first temperature and a second temperature, which is lower than the first temperature, is disclosed. The method includes placing the part in a shaft furnace, heating the part to the first temperature, lowering and fitting into the part an internal-sizing tool with an outer diameter greater than an inner diameter of the part at maximum structural shrinkage, transporting the assembly formed by the part and the sizing tool to a tempering vessel, cooling the part to a temperature below said second temperature, and extracting the internal-sizing tool. The method applies to the manufacture of turbomachine casings.

Abstract: Manufacturing heat-treatable wrought metal plate having length, width and thickness directions and an engineering properties gradient along at least one plate dimension. Rolled, extruded or forged wrought metal plate is solution heat treated and rapidly cooled. The cooled plate is aged by heat treatment for time to arrive at different tempers across at least one plate dimension (length or width). Controlled heat-input into the plate along its length direction raises plate temperature above ambient temperature to temperature T1, and a temperature gradient is applied between temperature T2 and T3, wherein T2>T3, across at least one direction of the plate by controlled heat-input into the plate from one side (width or thickness) of the plate to temperature T2 and controlled cooling to temperature T3 from the plate at the opposite side of the controlled heat-input, and ageing the plate while applying the temperature gradient between T2 and T3.

Abstract: To provide a technique suitable for elevating strength and toughness of a thin low-carbon steel. By performing rapid heating and rapid cooling to a thin low-carbon steel which is an ordinary steel with a thickness of 1.2 mm or less, a steel where a microstructure becomes a duplex grain size structure mixed with crystal grains having different grain diameters, which is not homogeneous, preferably, hard phase structures are contained in addition to the duplex grain size structure is obtained, and a high-strength and high-toughness thin low-carbon steel is obtained. Further, by performing a heat treatment process involving rapid heating and rapid cooling multiple times, a duplex grain size structure of crystal grains with smaller grain diameters or a hard phase structure contained therein is obtained, so that a thin low-carbon steel with higher strength and higher toughness is obtained.

Abstract: An apparatus and process for the dry removal of the scale from the surface of a metal product comprising at least one heating area that does not reduce the specific surface of the material to be treated and does not cause oxidation, at least one reducing area for performing the reaction between a specific reducing gas (normally hydrogen) and at least the scale, at least one cooling area for cooling the metal product, means for heating the metal product, means for heating the reducing gas, means for controlling the fluid dynamics of the boundary layer produced by the flow of said reducing gas over the surface of the metal product, means for removing the reaction products front the reducing gas after the reaction, means for cooling the metal product, and means for removing the reaction products from the treated surface of the metal product.

Abstract: A method and device for controlled straightening and cooling of a wide metal strip, especially a steel strip or sheet metal, running out of a hot rolled strip rolling mill, using pinching rollers arranged in the moving direction of the strip behind vertical double rollers, said pinching rollers producing a tensile stress acting in a longitudinal direction. According to the invention, the range of use of conventional sheet metal cooling systems can be extended to obtain a more even surface of said steel strip with an increased cooling effect. This is achieved by displacing the metal strip or sheet metal between a pre-straightening machine and splash cooling facility in defined conditions of tensile stress by adjusting the tensile stress and by cooling said strip or sheet metal inside said splash cooling facility between successive pairs of pinching rollers and by additionally controlling the tensile stress.

Abstract: Steel-sheet continuous annealing equipment includes, in sequence, a pre-heating zone, a heating zone, a soaking zone, a cooling zone, a reheating zone, an overaging zone, and a final cooling zone, and further includes a rapid heating region and a rapid cooling region that are provided within a range from the reheating zone to the final cooling zone (including the reheating zone and the final cooling zone), the rapid heating region allowing rapid heating of a steel sheet at a heating rate of 15° C./s or more and the rapid cooling region allowing rapid cooling, at a cooling rate of 10° C./s or more, of the steel sheet that has been rapidly heated in the rapid heating region. Various steel-sheet products ranging from mild steel sheets to ultrahigh-tensile steel sheets can be produced by performing a heat treatment with such steel-sheet continuous annealing equipment.

Abstract: A handling machine for handling rails, arranged in line immediately downstream of a rolling plant, which allows an optimal clamping of the rail along its longitudinal extension, thus effectively withstanding the deflection and its variations, while allowing a longitudinal movement of the rail caused by thermal shrinkage, thus avoiding damages both to the external surface of the rail and to the handlers. A process of handling the rail is also described, which optimizes moving, positioning along a roller table and maintaining the rail substantially rectilinear during the thermal treatment to which it is subjected.

Abstract: A system and method of induction heat treating a gear includes a workstation. The workstation has a power source, an inductor coil, and a rotational mechanism. The gear is induction heat treated at a first portion of the gear and a second portion of the gear remains untreated by induction hardening. The gear has an inner surface. The inner surface includes the first portion and the second portion. The first portion has a first width. The second portion has a second width. The inductor coil includes at least one heating loop and at least one non-heating loop. The inductor coil is energized to a predetermined frequency to create an alternating magnetic field, where the alternating magnetic field developed in the heating loop induces an eddy current in the first portion of the gear.

Abstract: One or more of the following quenching methods and apparatus: a quenching press for quenching a steel ring, a method of quenching a steel ring, a corresponding set of quenching dies for quenching steel rings, a die handling tool and related method to lift the corresponding set of quenching dies, and a die handling apparatus to load and unload dies to a quenching press.

Abstract: A water box for use in cooling a hot rolled product in a rolling mill comprises a plurality of nozzles arranged sequentially along a first axis. The nozzles are subdivided into base and top sections, with the top sections being adjustable between closed positions coacting with the base sections to define tubular enclosures through which the product is directed, and open positions. A clamp support extends in parallel relationship to the first axis, and carries clamp members. An operating mechanism adjusts the clamp support between an open setting at which the clamp members are separated from the nozzle top sections and the nozzle top sections are adjustable to their open positions, and a closed setting at which the top sections are in their closed positions and the clamp members are in contact with and urge the top sections into their closed positions.

Abstract: An apparatus for forming longitudinal thermal fatigue cracks. A heating unit has an induction coil disposed adjacent to an outer circumference of one side of a tubular test piece, on an inner surface of which a notch is formed. A cooling unit has a cooling water pump and a cooling water hose which forcibly injects cooling water from a cooling water storage source into an inner circumference of the tubular test piece. A control unit controls operation of the heating and cooling units. A cooling block partially encloses the outer circumference of the tubular test piece so as to control a magnitude of y-axial stress, is supplied with a cooling source of fluid or gas from an outside so as to repetitively cool the tubular test piece heated by the heating unit to adjust a temperature gradient, and has a longitudinal slit for controlling crack positions.

Abstract: An apparatus is described for cooling a metal strip (1), comprising at least two nozzle fields which are disposed opposite of each other with respect to the metal strip (1) conveyed continuously in its longitudinal direction and which comprise nozzles facing towards the respective strip surface and being attached to blowing boxes (3) for a cooling gas, and flow conduits (5) provided between the nozzles for discharging the cooling gas flows from the nozzles which are deflected on the surface of the strip.

Abstract: A cooling device including an air source, preferably a fan, that provides air flow and a shroud for directing air flow from the air source at an object, particularly a coil of material, preferably a metal or metal alloy having a temperature greater than the ambient room temperature. The cooling device provides cooling efficiency by directing the air from the air source at an increased velocity to a desirable area or areas on an end surface of the object, thereby increasing heat transfer from the object. The cooling device shroud includes an air directing surface that influences the direction of air flow across the object in a desired pattern. Methods for preparing cooling devices and for cooling objects are also described.

Abstract: In the production equipment for the precipitation hardened alloy strip, a solution treatment unit 20 includes a heating chamber 30 provided to heat material alloy strip 18 having a precipitation hardening alloy composition to a temperature of not lower than a recrystallization temperature but not higher than a melting point, a cooling chamber 40 located adjacent to the heating chamber 30, and a pair of cooling rolls 50 incorporated in the cooling chamber 40 to hold therebetween and cool down the material alloy strip 18 heated in the heating chamber 30. This production equipment can quench a material alloy strip to form a solid solution supersaturated with precipitation hardening elements and thereby give a precipitation hardened alloy strip having a good shape and a favorable surface condition.

Abstract: The present invention relates to an apparatus for a press hardening die which has a structure improved to decrease cooling rate of trimming portions in pressing a steel plate blank for manufacturing a part for press hardening. A press hardening die cooling device according to an embodiment of the present invention includes: a press hardening die composed of upper and lower dies equipped with cooling water suppliers therein to press a steel plate blank from the top and the bottom; and a cooling water temperature adjuster disposed between the cooling water suppliers of the upper and lower dies and the contact surface of the steel plate blank to adjust temperature of cooling water supplied to the steel plate blank.

Abstract: A method of treating a steel railway wheels to form a required distribution of compressive residual stress in the rim. In general terms the wheel heated and then quenched from the plate towards the rim. The wheel is first heated to form austenite throughout the plate and rim portions. The wheel is then cooled to form bainite/martensite in the plate portion. The wheel is cooled to form bainite/martensite in an inner portion of the rim. The wheel is cooled to form bainite/martensite in an outer portion of the rim.

Abstract: A method for tempering a workpiece is provided. The method includes providing a ferrous alloy workpiece having a martensite and/or bainite phase therein, heating at least a portion of the workpiece to a preselected temperature and then cooling the workpiece to a lower temperature. The preselected temperature is below the austensizing temperature of the alloy and the heating is accomplished in no more than 60 seconds. One embodiment of the present invention heats the workpiece using resistance heating.

Abstract: Steel-sheet continuous annealing equipment includes, in sequence, a pre-heating zone, a heating zone, a soaking zone, a cooling zone, a reheating zone, an overaging zone, and a final cooling zone, and further includes a rapid heating region and a rapid cooling region that are provided within a range from the reheating zone to the final cooling zone (including the reheating zone and the final cooling zone), the rapid heating region allowing rapid heating of a steel sheet at a heating rate of 15° C./s or more and the rapid cooling region allowing rapid cooling, at a cooling rate of 10° C./s or more, of the steel sheet that has been rapidly heated in the rapid heating region. Various steel-sheet products ranging from mild steel sheets to ultrahigh-tensile steel sheets can be produced by performing a heat treatment with such steel-sheet continuous annealing equipment.

Abstract: A method of quenching a ring shaped article includes a heating step (S1) of heating the article (W) to a quenching temperature; a primary cooling step (S2) of cooling the article (W) down to a deformation correction initiating temperature, which is higher than a martensitic transformation point; and a secondary cooling step (S3) of cooling the article (W) down to a temperature lower than the martensitic transformation point by, while a pair of receiving rolls (3) are held in contact with an outer peripheral surface of the article (W) for rolling motion about an axis of rotation parallel to a center of the article (W), pressing a press roll (4), rotatable about an axis of rotation parallel to the center of the article (W), against the outer peripheral surface of the article (W) from one side of the article (W) opposite to a point intermediate between the receiving rolls (3).

Abstract: A method and apparatus for the production of a casting comprises: —pouring molten material into a mould for forming the casting; —allowing the molten material to solidify; —removing the mould at least in part from the resulting solidified casting; and —locating the solidified casting in a chamber (10) that completely surrounds and facilitates a controlled rate of cooling of the casting.

Abstract: A method of cooling both surfaces of steel plate, which stably secures precision of cooling control from a start of cooling to an end so as to uniformly cool the top and bottom surfaces of the steel plate and thereby stably secures the steel plate quality and cools the steel plate down to a target temperature with a good precision. The method comprises dividing a steel plate cooling region into at least a spray impact part region and a spray non-impact part region, predicting a heat transfer coefficient for each divided region in advance, computing a predicted temperature history of the steel plate based on this predicted value, and setting and controlling amounts of sprayed coolant on the spray impact part regions by top and bottom surface nozzles.

Abstract: An apparatus for forming longitudinal thermal fatigue cracks. A heating unit has an induction coil disposed adjacent to an outer circumference of one side of a tubular test piece, on an inner surface of which a notch is formed. A cooling unit has a cooling water pump and a cooling water hose which forcibly injects cooling water from a cooling water storage source into an inner circumference of the tubular test piece. A control unit controls operation of the heating and cooling units. A cooling block partially encloses the outer circumference of the tubular test piece so as to control a magnitude of y-axial stress, is supplied with a cooling source of fluid or gas from an outside so as to repetitively cool the tubular test piece heated by the heating unit to adjust a temperature gradient, and has a longitudinal slit for controlling crack positions.

Abstract: A method and a device are provided for the thermomechanical treatment of seamless steel rings produced on radial-axial ring rolling machines, particularly rings of fine grain steel, heat-treatable steel, case hardened steel, or austenitic steel, preferably of steel tower flanges for wind turbine generators. The ring blank is inserted into the ring rolling machine at a temperature in the range of 900° C. to 1150° C. and is rolled to an outer diameter preferably in the range of 0.2 m to 10 m by a hot forming process. The hot ring (1) is quickly cooled down by a controlled process directly following the rolling, without secondary heating, from a temperature over the conversion temperature in the austenite range to a temperature below 400° C. The device includes a dipping basin filled with cooling liquid (8) or an unfilled cooling container, and a carrier (5) that can be lowered with a hoisting device (4), the rolled ring (1) lying on the carrier.

Abstract: A device for implementing a method of sizing a cylindrical part following shaping, by plastic deformation, of a metallic material that has maximum structural shrinkage at a maximum-shrinkage temperature between a first temperature and a second temperature, which is lower than the first temperature, is disclosed. The method includes placing the part in a shaft furnace, heating the part to the first temperature, lowering and fitting into the part an internal-sizing tool with an outer diameter greater than an inner diameter of the part at maximum structural shrinkage, transporting the assembly formed by the part and the sizing tool to a tempering vessel, cooling the part to a temperature below said second temperature, and extracting the internal-sizing tool. The method applies to the manufacture of turbomachine casings.

Abstract: An installation for the dry transformation of a material structure of semifinished products, particularly for dry bainitization, includes a quenching chamber and heating and/or cooling mechanism for setting the temperature prevailing on the inside of the quenching chamber, wherein the heating and/or cooling mechanism is developed as heating or cooling mechanism of a wall that borders on an inner chamber of the quenching chamber.

Abstract: A vacuum furnace adapted to cool a load. The vacuum furnace has one or more means for cooling a fluid and a muffle substantially containing the load. The fluid flows in a substantially unidirectional flow substantially within the muffle.

Abstract: An installation for the heat-treatment of parts includes a rotary hearth that can be rotated in a timed manner and which has an outer and an inner wall limiting a furnace chamber that is divided up into a heating zone and at least one treatment zone by vertically movable doors. The outer wall in the heating zone is provided with a closable opening for charging or discharging the furnace. The installation further comprises a transport device for transporting the parts into or out of the rotary hearth furnace and a quenching device. In addition, a second closable opening is disposed in the outer wall of the rotary hearth furnace in the last treatment zone. A sluice is disposed adjacent to the second closable opening and a quenching device is designed as a quenching bath and connected to the rotary hearth furnace via the sluice.

Abstract: An installation for the dry transformation of a material microstructure of semi-finished products, especially for dry bainitization, includes a quenching chamber and a microstructure transformation chamber situated downstream from it in the processing flow, in each case the inner space of the two chambers having applied to it excess gas pressure, at least during the respective method step, for the transformation of the material microstructure. Device(s) are provided for maintaining a minimum excess gas pressure acting on the semi-finished product, during the moving of the semi-finished product from the quenching chamber into the microstructure transformation chamber.

Abstract: System and method for hardening rails by cooling, in a cooling medium, at least one part of a respective rail cross-section of a rail over an entire length of the rail. The system includes a cross displacement device arranged in an area of a roller table, at least one positioning device, at least one coolant container containing the cooling medium, a manipulation gripper comprising a plurality of pincers and being structured and arranged to move the rail. The method includes at least one of moving the rail from the roller table to the at least one coolant container positioning the rail into the at least one positioning device via the manipulation gripper, as well as moving the rail into the coolant medium with the at least one positioning device.

Abstract: An apparatus for the heat-treating of a heat-hardenable steel cruciform article having a weld seam includes a heating element to heat the weld seam to a point that an austenitic transformation occurs, and a quenching chamber to cool the weld seam, causing the formation of Martensite and an associated expansion. The quenching is rapid since slow quenching may allow a crystalline phase other than martensite to form. The apparatus may comprise rollers operable to convey the welded cruciform article through the apparatus at a speed such that the weld seam is subjected to heating for a predetermined heat time sufficient to cause a formation of martensite there within, and such that the heated portion reaches the quenching chamber and is quenched to create a substantial amount of martensite, e.g., an amount sufficient to cause expansion of the part.

Abstract: A metal heat treatment method includes quenching a workpiece by blowing an inert gas onto the workpiece, adjusting the temperature of the inert gas to approximately an isothermal holding temperature of the workpiece for transformation of the workpiece, holding the isothermal holding temperature within a margin of error of approximately plus or minus five degrees Celsius for a given period, and performing a metal heat treatment with the isothermal holding temperature kept statically or dynamically by varying the temperature of the hot-gas.