KR20130100294A - Elevated temperature forming methods for metallic materials - Google Patents

Abstract

The method of forming a metal product includes the direct and / or indirect induction heating of a localized region of the metal product to a molding temperature. The metal product may include materials selected from titanium alloys, nickel-based alloys, and special steels such as stainless steel, high-strength low-alloy steel, sheath steel alloys, and the like. The molding temperature may be in the molding temperature range of 0.2 to 0.5 of the melting temperature of the metal material comprising the article. In the local area the metal product is molded. Devices for indirect and direct induction heating of localized areas of a metal product are disclosed. Articles are disclosed that include metal articles that are machined in accordance with the methods and / or devices taught herein.

Description

RELEASE TEMPERATURE FORMING METHODS FOR METAL MATERIALS

The present invention is directed to methods of forming hard-to-form metal materials, ie metals and metal alloys, using local direct or indirect induction heating.

For example, titanium, titanium alloys, nickel-based alloys, specialty steels (eg stainless steel, high-strength low-alloy steel (HSLA) It is generally known that certain metals and metal alloys, including high-strength low-alloy steel, armor steel alloys, etc., are difficult to form. Such metal materials are commonly referred to herein as "hard-to-form" metal materials. Refractory metal materials are generally more difficult to mold as their thickness, width, and / or length increase. Many refractory metal materials cannot be effectively and efficiently molded into the desired shapes or components without the use of a wide and expensive set of processing steps. Prior arts of manufacturing parts from refractory metal materials include welding multiple pieces together, machining or hogging out entire sections to provide the desired shapes, and orthopedic casting. improved molding techniques, such as net shape casting, forging, super-plastic forming, and the like. Many conventional forming techniques have limitations due to deterioration of the metal properties that exclude the techniques from the use of refractory metal materials. For example, the heat affected portion may result from welding and there may be machining and casting defects that are not easily detectable. Conventional molding of refractory metal materials typically involves significant post-molding operations for surface repair, flatness control, dimensional stability, appearance repair, and adjustment / recovery of desired mechanical properties.

Manufacturers have used direct heating of refractory metals and metal alloys with typical open torch technology, such as rose-bud torch technology. However, these methods only encounter mixed successes as the size of the component or part increases, and is generally less successful. Poor temperature control and poor heating uniformity are common drawbacks of these methods. For example, the use of open torch technology to heat the bend region of an alpha + beta titanium alloy plate may result in undesirable phase transformations due to poor temperature control. Can result in a beta phase at the surface of the plate, with increasing concentrations of alpha + beta phase microstructures moving towards the plate centerline.

Other known methods for bending refractory metal materials generally involve high temperature heating prior to and / or during molding. Such processes may require multiple heating steps to enable molding of the part. In addition, hot forming usually requires post-molding operations, such as annealing, surface conditioning, pickling, dimensional stabilization, and / or additional rework. In addition, such high temperature operations may require large furnaces, depending on the part size and dimensions of the molded component. Execution plans, feasibility, and cost can provide this processing unrealistic in terms of operation, scheduling, and cost.

Attempts have been made to develop improved techniques for the formation of refractory metal materials. For example, US Pat. No. 6,071,360 discloses a method for superplastic forming of thick titanium alloy plates. The plate is heated to superplastic temperatures, for example 1650 ° F. (898.9 ° C.), and molding takes place using a press ram. Completion of the part is achieved by machining the molded plate. The '360 patent describes that a 7.87 inch (20 cm) thick plate can be bent at about 130 ° with a 5 inch (12.7 cm) to 6 inch (15.24 cm) inner radius bend. In the embodiment of the '360 patent, a 2 inch (5.08 cm) thick plate was molded with a compound curvature exceeding 12 inches (30.48 cm) deep over an area of 30 x 60 inches (76.2 x 152.4 cm). One deficiency of the method described in the '360 patent is the high temperature and specialized equipment required to achieve superplasticity in alloy plates.

In view of the above discussion, there is a need for improved methods for bending and otherwise molding intractable metal materials.

According to one aspect of the invention, a method of forming a metal product comprises inductively heating a localized region of the metal product to a molding temperature. In a non-limiting embodiment, the molding temperature is in the molding temperature range of 0.20 to 0.50 of the melting temperature of the material in which the metal product is included. After induction heating of the local area, the metal product is molded in the local area. In non-limiting embodiments, the step of forming the metal product is bending, drawing, punching, stamping, and roll forming the metal product. At least one of the. In certain non-limiting embodiments, the metal product is a titanium alloy, a nickel-base alloy, a stainless steel alloy, a high-strength low-alloy steel -strength low-alloy steel, and a material selected from armor steel alloy.

According to another aspect of the invention, a method of bending a metal plate comprises induction heating a linear region of the metal plate to a bending temperature. In a non-limiting embodiment, the bending temperature is in the bending temperature range of 0.2 to 0.5 of the melting temperature of the metal material in which the metal plate is included. After induction heating of the linear region of the metal plate, the plate is bent along the linear region (ie in the linear region). In non-limiting embodiments, the metal material in which the metal plate is included is a material selected from titanium alloys, nickel-based alloys, stainless steel alloys, high-strength low-alloy steels, and exterior steel alloys.

According to another aspect of the invention, a method of forming a metal material comprises disposing a metal product comprising a material selected from a metal and a metal alloy on an iron alloy surface. The iron alloy surface is inductively heated to a predetermined temperature in a localized region of the iron alloy surface in contact with a localized region of the metal product, whereby the localized region of the metal product is formed at a forming temperature within a forming temperature range. Conductively heated. The metal product is molded in the local area. In non-limiting embodiments, the metal product comprises a metal material selected from titanium alloys, nickel-based alloys, stainless steel alloys, high-strength low-alloy steels and sheath steel alloys. In another non-limiting embodiment, the forming temperature range is 0.2 to 0.5 of the melting temperature of the metal material.

According to a further aspect of the invention, a method of bending a metal plate comprises placing a metal plate comprising a metal material selected from a metal and a metal alloy on an iron alloy surface. The linear region of the iron alloy surface in contact with the linear region of the plate is inductively heated to a predetermined temperature, whereby the linear region of the metal plate is conductively heated to a bending temperature within the bending temperature range. The metal plate is bent in the linear region of the metal plate. In a non-limiting embodiment, the bending temperature range is 0.2 to 0.5 of the melting temperature of the metal material. In other non-limiting embodiments, the metal plate comprises a metal material selected from titanium alloys, nickel-based alloys, stainless steel alloys, high-strength low-alloy steels and sheath steel alloys.

According to a further aspect of the invention, a device for indirect local heating of a metal product comprising a material selected from metals and metal alloys comprises a support comprising an iron alloy surface, and at least one induction heating device. The at least one induction heating device is positioned and adapted to inductively heat a localized area of the iron alloy surface. The induction heated localized region of the iron alloy surface is adapted to heat the localized region of the metal product located on the iron alloy surface to a predetermined temperature.

According to another aspect of the invention, a device for direct local heating of a metal product comprising a material selected from metals and metal alloys comprises a support comprising a support surface. At least one induction heating device is positioned and adapted to inductively heat a localized region of the metal product located on the support surface to a predetermined temperature. The support and the support surface comprise a material that is not induction heated by the at least one induction heating device.

An additional aspect of the present invention relates to a system for bending a metal product comprising a material selected from metals and metal alloys. The system includes a support comprising an iron alloy surface, and at least one induction heating device. The at least one induction heating device is positioned and adapted to inductively heat a predetermined linear region of the iron alloy surface. The induction heated linear region of the iron alloy surface is adapted to conduct conductive heating of the linear region of the metal product located on the iron alloy surface to the bending temperature in the bending temperature range. The system further includes a metal material bending apparatus positioned in proximity to the iron alloy surface and adapted to bend the metal product along the linear region before the linear region cools below the bending temperature range.

Another aspect of the present invention relates to a molded ballistic armor comprising a metal material selected from titanium alloys, nickel-based alloys, stainless steel alloys, high-strength low-alloy steels and sheathed steel alloys, The plate has at least one bending area having a bending radius of at least 2 t. The shaped ballistic plate can be provided, for example, as a monolithic hull, V-type hull, explosion protection vehicle underbelly, or enclosure.

A further aspect of the present invention relates to an article of manufacture comprising a molded ballistic faceplate according to the present invention. The shaped ballistic plate may be, for example, in the form of a monolithic hull, a V-shaped hull, an explosion protection vehicle underbelly, or an enclosure. In certain embodiments, the shaped ballistic plate may comprise one of a titanium alloy, a nickel-based alloy, a stainless steel alloy, a high-strength low-alloy steel, and a sheathed steel alloy, having a bend radius of at least 2 t. It may include at least one bending area.

Features and advantages of certain non-limiting embodiments described herein may be better understood with reference to the accompanying drawings.
1 is a flow chart of a non-limiting embodiment of the present invention of a method for forming an article comprising a refractory metal material.
2 is a schematic representation of a non-limiting embodiment according to the present invention of a method comprising induction heating a plate or a linear region of a plate of refractory metal material.
3 is a flow chart of a non-limiting embodiment according to the present invention of a method for bending or otherwise forming a plate, plate, or other article of a refractory metal material.
4 is a schematic of a non-limiting embodiment according to the present invention of a method of using indirect induction heating to indirectly heat a linear or other localized region of a refractory metal plate, sheet, or other product to form a metal product. It is an expression.
5 is a schematic representation of a non-limiting embodiment of a support comprising an iron alloy surface, and a device comprising at least one induction heater. The at least one induction heater is thereby arranged and adapted to inductively heat the localized region of the iron alloy surface in a substantially uniform manner to conduct conductive heating of the localized region of the metal product in a substantially uniform manner.
6 is a schematic representation of a non-limiting embodiment of a device comprising a support and at least one induction heater. At least one induction heater is arranged and adapted to inductively heat a localized region of the metal product disposed on the surface of the support in a substantially uniform manner. The support comprises a material that is not induction heated by at least one induction heater.
7A and 7B show schematic representations of a non-limiting embodiment of a support for a device for direct and indirect induction heating of local regions of a metal product.
8 shows a non-limiting embodiment of a system for forming a metal product, wherein the device is adapted to enable forming of the metal material before the temperature of the local region of the metal product is cooled below the forming temperature range. And an induction heating device adapted to heat a localization of the metal product and the molding apparatus located near the induction heating device.
9 is a schematic representation of a non-limiting embodiment according to the present invention of a shaped ballistic face plate having at least one bending radius of about 2 t.
10 is a photograph of a non-limiting embodiment of a heating device according to the invention, in the form of a heating table.
11 is a 1-inch (2.54 cm) thick ATI 425 ^® titanium alloy (Ti-4Al-2.5V) bent at increasing radii of 1t to 6t using a non-limiting embodiment of the method according to the present invention. -1.5Fe-0.25O ₂ (UNS R54250)) Pictures of plate samples.
FIG. 12 is a plot of temperatures in a local region of titanium alloy cooled for 60 seconds as a function of distance from the centerline of the local region inductively heated for 900 seconds and then heated.
Given the following detailed description of specific non-limiting embodiments in accordance with the present invention, the reader will understand the foregoing details as well as others.

In the present description of non-limiting embodiments, indicated in addition to or in other ways of operation, all numbers expressing quantities or characteristics are to be understood as changed in all instances by the term “about”. Should be. Thus, unless indicated to the contrary, any numerical parameters set forth in the following description are approximations that may vary depending on the desired properties to be obtained by the methods according to the invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of significant digits recorded and by applying ordinary rounding techniques. In addition, all ranges provided herein include the indicated boundaries or restrictions. For example, a temperature range of "0.2 to 0.5" of a particular temperature includes the indicated boundaries of 0.2 and 0.5 of that particular temperature.

Any patent, publication, or other disclosure material that may be said to be incorporated in its entirety or in part by reference herein does not conflict with the existing definitions, descriptions, or other disclosure materials set forth herein. To what extent is integrated here. As such, and to the extent necessary, the present invention as set forth herein supersedes any conflicting material incorporated herein by reference. Although it can be said that this is incorporated by reference herein, any material that conflicts with existing definitions, descriptions, or other disclosure materials, or portions thereof, is merely a conflict between the integrated data and existing disclosure materials. It is integrated only to the extent that it does not occur.

There is a need for improved methods for bending and otherwise molding hard-to-form metal materials. For example, the inventors have found that refractory metal materials that do not require the use of open torches, large furnaces, and associated logistics, or heating of materials to superplastic temperatures. It was concluded that it would be advantageous to provide a way to mold them. The inventors believe that this method can reduce the costs of molded components, increase productivity, and / or reduce the thermomechanical processing apparatus infrastructure currently required for molding many difficult shaped metal materials. In addition, the inventors believe that this method will enable the production of parts from alloys not previously used for these parts due to new part design criteria, ie limitations of conventional production techniques.

1 is a flow diagram schematically illustrating a non-limiting embodiment according to the present invention of an elevated temperature forming method of a metal product comprising a refractory metal material. As used herein, the term "hard-to-form metallic material" refers to metals and metal alloys having high strength and ductility at forming temperatures, and to smooth flow during deformation. Losing refers to metals and metal alloys. In a non-limiting embodiment, the refractory metal material has a difference of less than 10% in tensile strength and yield strength at molding temperatures. In another non-limiting embodiment, the refractory metal material is a metal or metal alloy that exhibits high spring back, such as, for example, with titanium alloys. As used herein, refractory metal materials are, for example, titanium alloys, nickel-based alloys, and specialty steels (eg, stainless steel, high). Strength low-alloy steel (HSLA: high-strength low-alloy steel, and armor steel alloys). Also, as used herein, “metallic” refers to a material or article comprising a metal and / or a metal alloy.

Although the embodiment disclosed in FIG. 1 refers to specific refractory metal materials, the embodiments described herein are comprised of high purity metals, commercially pure metals, and refractory metal materials. It may be used when forming other metal alloys that are considered or not considered. (Also, to reduce repetition in the present discussion, any reference to "metal alloy" in the continuing discussion of embodiments according to the present invention includes pure base metals). One non-limiting example of a refractory high purity metal that can be processed according to the embodiments disclosed herein is high purity zirconium.

Referring to FIG. 1, a non-limiting method 10 according to the invention for forming a metal product, ie a product comprising a refractory metal or a metal alloy product, may be used to form a localized region of the metal product at a forming temperature range. Induction heating to a forming temperature (12). When the local area is at the desired molding temperature, the article is bent or otherwise molded 14 in the induction heated local area.

In a non-limiting embodiment, the molding temperature is in the molding temperature range of 0.2 to 0.5 of the melting temperature (T _m ) of the metal or metal alloy comprising the metal product. In another non-limiting embodiment, the molding temperature is in the molding temperature range of 0.24 to 0.3 of the melting temperature of the metal or metal alloy comprising the metal article. In another non-limiting embodiment, the molding temperature range is from about 0.2 of the melting temperature to a temperature lower than the recrystallization temperature of the metal or metal alloy comprising the metal product. As used herein, "melting temperature" is defined as the lowest temperature at which just-initiated melting of a metal or metal alloy occurs. As used herein, “recrystallization temperature” is defined as the lowest temperature at which a distorted crystal structure of a cold-processed metal or metal alloy is replaced with a new, unmodified crystal structure during subsequent heating.

As used herein, a "titanium alloy" is a metal alloy comprising titanium as the main element. As used herein, a "nickel base alloy" is a metal alloy comprising nickel as the main element. As used herein, “specialty steel” is not limited to this, but is not limited to electric steels, alloy steels, stainless steels (ferritic, martensitic, austenitic) , Including super-austenitic, duplex, and precipitation hardening stainless steels, tool steels, maraging steels, exterior steel alloys , High strength low alloy steels, and wear steels.

Referring again to FIG. 1, the step 14 of forming the metal product is, but is not limited to, bending, drawing, punching, stamping, and roll forming. May include techniques selected from. In another non-limiting embodiment, the metal product comprises a mill product. As used herein, a "mill product" is any metal (ie metal or metal alloy) product that is used as is, or further manufactured as a finished product. In a non-limiting embodiment according to the invention, the factory product is ingot, billet, bloom, round bar, square bar, extrusion, tube ), Pipe, slab, sheet, and plate. In another non-limiting embodiment according to the invention, the metal product comprises a metal plate, the local area of the metal plate to be inductively heated comprises a linear area, and the step 14 of forming the metal plate comprises a linear area of the metal plate. Bending the metal plate.

As used herein, a "localized region" is the area of the metal product to be plastically deformed during the forming step. Also, a "local area" may include one or more areas immediately adjacent the area of the metal product to be plastically deformed. For example, in certain non-limiting embodiments in accordance with the present invention, the local area can be up to about 0.5 inches (1.27 cm), up to about 1 inch (2.54 cm), up to about 2 inches (5.04 cm), about It can extend up to 3 inches (7.62 cm), up to about 4 inches (10.16 cm), or a greater distance from the area of the metal product to be plastically deformed. For example, in addition to induction heating of the area to be plastically deformed, as well as induction heating and / or plastic deformation of one or more areas immediately adjacent to the area to be plastically deformed when the method is performed on thicker metal products. It is anticipated that it may be desirable to further ensure that the area is at the molding temperature during the molding step.

In a non-limiting embodiment of the method according to the invention, the local region to be inductively heated is a linear region. As used herein, a "linear region" is an elongated region that includes the intended bend line (ie, the centerline of the bend) of a metal plate or other product. In addition, the linear region can extend the distance from the intended bend line. For example, the linear region can be about 0.5 inches (1.27 cm) up to about 1 inch (2.54 cm) up to about 2 inches (5.04 cm) up to about 3 inches (7.62 cm) up to about 4 inches (10.16 cm) Or a greater distance from the intended bend along an area or all of the length of the intended bend. In certain embodiments, the distance from the intended bend line defining the boundary of the linear region increases as the thickness of the plate or other article to be bent or otherwise molded using the methods herein.

In non-limiting embodiments according to the present invention, inductively heating a linear region or other local region involves using one or more induction heating coils positioned adjacent to a local region of a plate or other product. . 2 is a schematic representation of a non-limiting embodiment according to the present invention of a method of induction heating 20 a linear region 22 of a plate 24 of a refractory metal or metal alloy. Linear region 22 is bounded by lines 22a in FIG. 2. In the non-limiting embodiment represented by FIG. 2, the linear region 22 comprises two induction coils (positioned adjacent to opposite surfaces 28, 29 of the linear region 22 of the plate 24). induction coils (26). FIG. 2 shows two induction coils 26 used to heat the linear region 22 of the plate 24, although one induction coil 26 or more than two induction coils 26 may be used. It is understood that it can be used to heat linear region 22 of 24. Thus, for example, to place one or more induction coils adjacent to opposite surfaces of one or both of the linear region or other local region of a metal plate or other product to heat the local region of the article to the molding temperature. It is within the scope of the present invention. It will be appreciated that the foregoing discussion regarding the number and positioning of induction coils relative to the local region of the metal product applies to any geometry of the local region that can be used in the methods according to the invention.

For purposes herein, induction heating using an arrangement of induction coils, such as, for example, induction coils 26, located directly adjacent to a metal or metal alloy product, such as plate 24, Referred to herein as "direct" induction heating. In direct induction heating, one or more induction coils or other induction heating devices induce a current in a localized region of the metal product, thereby causing the temperature of the localized region to increase. Direct induction heating can be contrasted with "indirect" induction heating, where a current is induced in and thereby heats the region of the metal body, which insulates the conduction of heat from the induction heated metal body to the metal product. To heat the local area of the metal product. Thus, in direct induction heating, the induction heating device inductively heats the metal or metal alloy product to be bent or otherwise molded without depending on inductively heating the interposing metal or metal alloy.

Induction heating is a technique used to heat electrically conductive objects, such as metals or metal alloys, by electromagnetic induction, where high frequency alternating current is transmitted through electromagnets and induction coils. The induction coil is located adjacent to the metal body and the current in the coil generates eddy currents in the object. Electrical resistance inside the metal body results in Joule heating of the object. The frequency of alternating current that must be used for induction heating of a particular metal or metal alloy depends on the object size, the composition of the metal or metal alloy, the specific coupling between the object to be heated and the induction coil, and the penetration depth of induced eddy currents. In non-limiting embodiments according to the invention, an induction heating device used for heating a linear region or other localized region of an article comprising a refractory metal material is used to efficiently and properly heat the metallic article. Use clearly tuned AC frequencies. Induction heating is known to those skilled in the art, and further elaboration of the principles and manners for carrying out the technology is deemed unnecessary in the present disclosure.

In certain non-limiting embodiments according to the present invention, the forming or bending temperature is about 0.2 times the melting temperature of the refractory metal or metal alloy (0.2T _m ), and the melting temperature of the refractory metal or metal alloy (0.5) T _m ) up to about 0.5 times. Therefore, in view of the relatively low temperatures used, an aspect of non-limiting embodiments according to the present invention is that the embodiments can be considered to be "warm forming" methods. Although not limited thereto, refractory metal materials, such as titanium alloys, nickel-based alloys, and special steels, may be bent at other temperatures or substantially lower than the melting temperatures of the materials without cracking the material during molding. And, after molding, the plastically deformed area is in the form of linear defect indications in the form of macro-surface and micro-surface cracks, for example resulting from bending or other shaping steps. It was unexpected and surprising for the inventors to be completely or substantially free of surface defects, such as linear indications.

In a non-limiting embodiment according to the invention wherein the method is carried out on a titanium alloy article, the forming or bending temperature range is in the forming or bending temperature range of 750 ° F. (398.9 ° C.) to 850 ° F. (454.4 ° C.), or It may be in the forming or bending temperature range of 800 ° F. (426.7 ° C.) to 850 ° F. (454.4 ° C.). According to one non-limiting embodiment, the forming or bending temperature for the titanium alloy article is about 800 ° F. (426.7 ° C.), while in another non-limiting embodiment, the forming or bending temperature for the titanium alloy article is About 850 ° F (454.4 ° C). According to certain non-limiting embodiments, when a metal product that is bent or otherwise plastically deformed consists of or comprises a Ti-4Al-2.5V-1.5Fe-0.25O ₂ alloy (UNS R54250), The forming or bending temperature range can be 728 ° F. to 874 ° F. (387 ° C. to 468 ° C.). In other non-limiting embodiments according to the invention, wherein the metal material consists of or comprises a titanium alloy, the forming or bending temperature range is about below the beta transus temperature (T _β ) of the titanium alloy. in 1000 ℉ (555.6 ℃) to about 700 ℉ (388.9 ℃) below the beta-transformation temperature of titanium alloys that is, T _β to T _β -700 -1000 ℉ ℉ is in the (Tβ-555.6 ℃ to T _β -388.9 ℃) Can be.

Most conventional processes for forming titanium alloys use temperatures higher than 1000 ° F. (537.8 ° C.). At these "hot forming" temperatures, the surfaces of the titanium alloys can be oxidized to form an alpha-case. The alpha-case is the oxygen-enriched phase that results when titanium and its alloys are exposed to heated air or oxygen. Since the alpha-case is brittle and tends to cause fatigue cracks in the alloy, it is typically removed in subsequent processing steps. Little or no alpha-case molds at the molding temperatures used in the various non-limiting embodiments of the molding methods disclosed herein.

Also, above about 1000 ° F. (537.8 ° C.), the mechanical properties of titanium alloys may vary. For example, the ballistic properties required for titanium alloys for exterior applications, such as, for example, high toughness, may be lost when thermomechanical processing of the titanium alloy at hot forming temperatures. In such a case, heat treatments following hot forming may be required to restore the desired mechanical properties in the alloys. For some refractory metal materials, it may not be possible to recover the desired mechanical properties using post-form heat treatments. The inventors have observed that it is not significantly affected by the important mechanical properties of the alloys that the titanium alloys and other metal alloys undergo the relatively low forming temperatures used in the non-limiting embodiments disclosed herein. As suggested, particularly important mechanical properties may be those required for ballistic sheathing and / or other applications.

In certain non-limiting embodiments of the methods according to the invention in which titanium alloys are bent or otherwise molded, because the bending or forming temperature is lowered, molding or bending to a reproducible and more stringent radius of the process Both ability to decrease. For example, because the bending or forming temperature is lowered, a higher incidence of "spring back" of the plate or other product that is bent or otherwise molded occurs. As is known in the art, for example, after a plate is bent, the bend plate springs back when it returns to a bending radius larger than that of the bent. In addition, as the bending temperature used is lowered, the risk of micro-cracking at the bending line increases. Therefore, in a non-limiting embodiment according to the invention of a method for bending or other forming titanium alloy products, the lower limit for bending or other forming temperature is about 750 ° F. (398.9 ° C.). In another non-limiting embodiment of the present invention of a method for bending or other forming titanium alloy products, the lower limit for bending or other forming temperature is about 700 ° F. (371.1 ° C.). In another non-limiting embodiment of the present invention of a method for bending or other forming titanium alloy products, the lower limit for bending or other forming temperature is from about 700 ° F (371.1 ° C) to about 900 ° F (482.2 ° C). Is in the molding temperature range. Generally, but not limited to, refractory metals, such as titanium alloys, nickel-based alloys, and special steels (eg, stainless steel, high-strength low-alloy steel (HSLA), sheath steel alloys, etc.). In various non-limiting embodiments according to the invention of the methods for bending and other forming metals and metal alloys comprising materials, the lower limit of the forming temperature range is about 0.2T _m . Also, in general, but not limited to, i.e., titanium alloys, nickel-based alloys, and special steels (eg, stainless steel, high-strength low-alloy steel (HSLA), sheathed steel alloys, etc.). In various non-limiting embodiments according to the invention of the methods for bending and other forming metals and metal alloys including shaped metal materials, the molding temperature range is from about 0.2T _m to about 0.5T _m .

During the development of a "warm forming" method for forming or bending refractory metal materials, the inventors have found that the entire plate can be heated in a furnace to a bending temperature as disclosed herein, and that the plate is in the bending temperature range. It was observed that the plate was successfully bent when transferred from the furnace to the press break before cooling out. However, the furnace capable of heating the entire plate must be relatively large, and heating the entire plate to a uniform temperature can take considerable time, reducing yield and complicating the processing from the furnace to the forming equipment. .

In embodiments according to the invention, local induction heating of a linear or other local region of a metal product can be achieved relatively quickly. In certain non-limiting embodiments, induction heating of a linear or other local region can be performed, for example, within 5 to 10 seconds, within 1 minute, within 2 minutes, within 20 minutes, within 30 minutes, or within 60 minutes. Can be achieved. Other induction heating times possible in certain non-limiting embodiments can be from about 3 minutes to about 20 minutes. The heating time can be extended to further ensure that "cold spots" are not present in the linear region or other localized region being heated. As used herein, a "cold spot" is an area within a linear or other local area that is cooler than the desired bending or other forming temperature and is outside the bending or other forming temperature range. Thicker metal plates and other thicker metal products may require longer heating times to reach the desired molding temperature. However, in certain non-limiting embodiments according to the invention, one or more induction coils are suitably adjusted to join and heat the metal or metal alloy product to be plastically deformed, and the induction coils are linear or If properly positioned relative to other local zones, the local zone can be heated to the desired molding temperature without cold spots in less than 30 seconds. In a non-limiting embodiment, the linear region of a 1 inch-thick 18 inch by 120 inch titanium alloy sheet can be directly induction heated to a uniform bending temperature of about 850 ° F. (454.4 ° C.) within 10 minutes, without cold spots. have.

Referring again to FIG. 1, after induction heating of a refractory metal sheet or other product, the product is transferred to a forming apparatus. In the non-limiting embodiment shown in FIG. 2, for example, the linear region 22 of the plate 24 is rapidly induction heated by the induction coils 26 to a bending temperature within the bending temperature range, and then thereafter. Plate 24 is bent to a desired bend radius on a forming apparatus (not shown). In a non-limiting embodiment according to the invention, bending or shaping is achieved on a press brake or other forming apparatus. The forming apparatus further ensures that the induction heated forming or other localized region of the metal plate or other product can be bent or otherwise molded before the temperature of the local region is cooled to a temperature below the molding temperature range. To be in close proximity to the induction heating device.

Although the non-limiting embodiment shown schematically in FIG. 2 involves bending of the plate 24 after it is heated to the bending temperature, other forming processes for plastically deforming the heated product are within the scope of the embodiments disclosed herein. Will be recognized. For example, such other forming processes include, but are not limited to, drawing, punching, stamping, roll forming, and similar forming processes. In addition, while certain embodiments discussed herein involve induction heating of linear or other local areas and bending of heated products, it will be appreciated that the present invention is not limited to such arrangements. For example, non-limiting embodiments according to the present invention relating to stamping or stamping processes involve direct and / or indirectly heating the local area of a metal product to be plastically deformed in a stamping or stamping operation. It may be accompanied. Other configurations of induction heating of the localized region of the metal product included within the present invention may be specific to other forming processes, and those skilled in the art who consider the present invention may adapt the methods herein for these applications without undue experimentation. have.

Titanium alloys that can be formed using certain non-limiting embodiments of warm forming according to the present invention include, but are not limited to, near-alpha titanium alloys, alpha + beta titanium alloys, and for example. Beta titanium alloys, including near-beta and metastable beta titanium alloys. In certain non-limiting embodiments, titanium alloys that can be bent or otherwise molded using the warm forming methods according to the present invention are not limited thereto, but ASTM Grades 5, 6, 12, 19, 20, 21, 23, 24, 25, 29, 32, 35, 36, and 38 titanium alloys. In certain non-limiting embodiments, the local area of the article of grade 38 titanium alloy (UNS R54250) is induction heated and bent or otherwise molded according to embodiments of the warm forming methods herein. In another non-limiting embodiment, the local region of the product of the grade 5 titanium alloy (UNS R56400), also referred to as Ti-6-4 alloy and Ti-6Al-4V alloy, is induction heated, and the embodiments disclosed herein Depending on the examples it is warm bent or otherwise warm molded. In another non-limiting embodiment, 4.5% aluminum, 2% molybdenum, 1.6% vanadium, 0.5% iron, 0.3% silicon in weight percentages based on nominal total alloy weight And a localized region of the grade 35 titanium alloy (UNS R56340), including balance titanium and incidental impurities, is induction heated and bent warmed or otherwise warm formed according to the embodiments disclosed herein. .

According to a non-limiting aspect of the invention, the warm forming method according to the invention comprises the steps of induction heating a linear region or other local region of a metal product made of high hard specialty steel to a forming temperature and Bending or otherwise forming a high hardness special steel product by plastic deformation of a linear or other localized area. According to a non-limiting embodiment of the invention, a high hardness special steel sheath, which is a high hardness special steel sheath, is machined according to the methods herein. According to certain non-limiting embodiments, the high hardness special steel processed by the methods herein can be made of 400 BHN steel sheath, 500 BHN steel sheath alloy, 600 BHN steel sheath alloy, 700 BHN steel sheath, and high strength. Low alloy steels.

Sheath steel alloys can generally be classified or identified according to their hardness as follows: Homogeneous rolled steel sheet ("Brill hardness number) hardness range of 212-388 BHN under MIL-A-12560H" RHA ": Rolled Homogeneous Armor) alloys; High hardness armor ("HHA": High Hard Armor) alloys having a hardness range of 477-535 BHN under MIL-DTL-46100E; And ultra high hardness sheath ("UHH": Ultra High Hard Armor) alloys with a minimum hardness of 570 BHN under MIL-DTL-32332. According to certain non-limiting embodiments, the sheath steel alloys processed by the methods herein include, but are not limited to, RHA, HHA, and UHH alloys.

In a non-limiting embodiment, the local region of the plate or other article of the sheath steel alloy comprising one of the RHA alloy, the HHA alloy, and the UHH alloy is induction heated and bent warm according to the embodiments disclosed herein or Or by other means. In another non-limiting embodiment, the localized region of the plate or other article of 500 BHN steel sheath alloy is induction heated and bent warmed or otherwise molded according to the embodiments disclosed herein. One non-limiting example of a 500 BHN steel sheath alloy that can be processed in accordance with the present invention is the market sector team of Allegheny Technologies, Inc., PA, Washington, ATI ATI 500-MIL ^® high hardness special steel sheath alloy, available from ATI Defense. In another non-limiting embodiment, the localized area of the plate or other article of 600 BHN steel sheath alloy is induction heated and bent warmed or otherwise molded according to the embodiments disclosed herein. The ratio of the number to be processed 600 BHN steel sheath alloy in accordance with the present invention-limiting example is a high-hardness special steel sheath possible ATI 600-MIL ^® available from ATI Defense.

It is recognized that bending or other forming of metal and metal alloy products becomes increasingly difficult as the thickness of the products increases. As discussed above, the inventors have found that the plates of refractory metal materials can be induction heated in a localized region with a relatively low molding temperature, and bent or otherwise caused without causing the formation of bent surface defects such as micro-cracks. It has been found that it can be molded into. In a non-limiting embodiment, the metal or metal alloy plate or other article processed by the methods herein is at least 0.125 inches (3.175 mm) thick. In another non-limiting embodiment, the metal or metal alloy plate or other article processed using the methods herein is at least 0.1875 inches (4.763 mm) thick. The thickness of plates or other articles that can be bent or otherwise molded according to the non-limiting embodiments disclosed herein can be up to about 2 inches (5.08 cm) or, in some cases, up to about 1 inch (2.54). cm), where the thickness is in the region to be plastically deformed in the method. According to a non-limiting embodiment of the method according to the invention for bending or otherwise forming a titanium alloy sheet, a brake press or other forming equipment having a performance of 1000 to 1500 tons (8.896 MN to 13.34 MN) Is enough to bend a 1.5 inch (3.81 cm) thick plate. The thickness of the plate which can be bent or otherwise molded according to the embodiments of the warm forming methods herein is considered to be limited only by the performance of the brake press or other forming equipment used. It is also recognized that bending or other forming of metal and metal alloy sheets, ie, articles having a thickness of less than 0.1875 inches (4.763 mm), is within the scope of the embodiments disclosed herein.

Because the molding temperatures used in the methods herein, for example molding temperatures in the temperature range of 0.2T _m to 0.5T _m , are relatively low, the specific mechanical properties of the linear or other local region of the induction heated metal or metal alloy product The properties are substantially unchanged after the bending or other forming step. As used herein, the mechanical properties are not "substantially changed" if the properties do not change or change from the original value to 10% or less, or in some cases to 5% or less.

According to certain non-limiting embodiments of the present invention, titanium alloys, nickel-based alloys, and special steels (eg, stainless steel, high-strength low-alloy steel (HSLA), sheathed steel) It is particularly surprising to the inventors that refractory metal materials, such as alloys, etc., can be locally induction heated to relatively low temperatures and bent to tight radii. For example, according to a non-limiting embodiment herein comprising induction heating and bending of a linear region of a metal product selected from titanium alloy plates, nickel-based alloy plates, and special steel plates, Bend to a bending radius of at least 6t. As used herein, a "bend radius" is a radius, measured for internal curvature, that destroys a plate or other metal product, forms surface cracks, or mechanical properties of the metal product in the bending region. They can be bent without significant deterioration. The value of the bending radius is given relative to the thickness "t" of the plate or other product. A plate bent at a radius of 1 t includes a bend having a radius, measured inside of the radius of curvature, for example equal to the thickness of the plate. In other non-limiting embodiments, including induction heating and bending of a linear region of a metal product selected from titanium alloy plates, nickel-based alloy plates, and special steel plates, the article is at least 4t or at least 2t. Is bent to the radius of. In another non-limiting embodiment comprising inductively heating and bending a linear region of a metal product selected from titanium alloy plates, nickel-based alloy plates, and special steel plates, the article has a radius of at least 1 t. Is bent.

A non-limiting aspect of this invention utilizes indirect induction heating to heat linear or other localized areas of a metal plate or other product and a forming step to warm the metal product. 3 is a plate or other material of a refractory metal material, such as, for example, titanium alloys, nickel-based alloys, or special steels (eg, stainless steel, high-strength low-alloy steel (HSLA), sheathed steel, etc.). A flow chart of a non-limiting embodiment according to the present invention of a method 30 for bending or otherwise molding an article. 4 is a schematic diagram of an arrangement 40 of equipment and materials used in a non-limiting embodiment according to the present invention, where indirect induction heating is a linear or other localization of a metal plate or other product for warm forming the metal product. It is used to indirectly heat the phosphorus region.

Referring to the method 30 and the arrangement 40 of FIGS. 3 and 4, respectively, a non-limiting embodiment of indirect induction heating for warm forming a metal product is a metal product 42 on an iron alloy surface 44. And arranging (32). In a non-limiting embodiment, the metal product 42 comprises a refractory metal material. After placing the metal product 42 on the iron alloy surface 44, the iron alloy surface in contact with the local area 48 (roughly bounded by lines 48a) of the metal product 42 ( Local area 46 of 44 is induction heated 34 to a predetermined temperature. Induction heating of the ferroalloy surface 44 conducts conductive heating of the localized region 48 of the metal product 42 to a forming temperature within the forming temperature range.

In a non-limiting embodiment, the predetermined temperature at which the localized region 46 of the iron alloy surface 44 is heated is the forming temperature of the metal product 42. In another non-limiting embodiment, the predetermined temperature at which the localized region 46 of the iron alloy surface 44 is heated is the molding temperature in the molding temperature range of the metal product 42. In another non-limiting embodiment, the predetermined temperature at which the localized region 46 of the iron alloy surface 44 is heated is higher than the forming temperature of the metal product 42. However, preferably, the temperature at which the localized area 48 of the metal product 42 is electrically heated does not exceed the upper limit of the forming temperature range of the metal product 42.

As further shown in FIG. 4, in arrangement 40, inductively heating the localized region 46 of the ferroalloy surface 44 may result in the localized region 46 of the ferroalloy surface 44 to be inductively heated. One or more induction coils 50 disposed on the opposite side 52 can be used. 4 shows an arrangement in which one induction coil 50 heats the localized region 46 of the ferroalloy surface 44, while more than one induction coil has a localized region 46 of the ferroalloy surface 44. It will be appreciated that it can be used to heat). As shown in the non-limiting embodiment of FIG. 4, the above discussion regarding the possible number of induction coils and their positions for heating a localized region is not limited to various types of warm forming operations within the scope of the present invention. It will be appreciated that the same applies to other local area geometries that may be used in the art.

In a non-limiting embodiment according to the invention using indirect induction heating, the local region 48 of the metal product 42 is a local region 46 of the iron alloy surface 44 at a forming temperature in the forming temperature range. When electrically heated, the metal product 42 is then bent or otherwise molded 14 by plastic deformation of the metal product 42 in the localized region 48 of the metal product 42.

In a non-limiting embodiment according to the present invention, the indirect induction heating method disclosed herein is not limited thereto, but titanium alloys, nickel-based alloys, and special steels (eg, stainless steel, high-strength low-alloy) Metal products including refractory metal materials, such as steel (HSLA), facing steels, etc.), and may be used to bend and otherwise form. In addition, in a non-limiting embodiment according to the invention, the indirect induction heating method disclosed herein is characterized in that the induction heating method of the metal product is carried out at a forming temperature in the range of 0.2 to 0.5 of the melting temperature of the metal or metal alloy comprising the metal Heat the local area. In another non-limiting embodiment according to the invention, the indirect induction heating method disclosed herein is characterized in that the metal product is formed at a forming temperature in the forming temperature range of 0.24 to 0.30 of the melting temperature of the metal or metal alloy comprising the metal product. Heat the local area.

In certain non-limiting embodiments of the methods disclosed herein, and in particular with reference to FIGS. 3 and 4, the forming 36 is not limited thereto, such as bending, drawing, punching, stamping, and roll forming, Processes. In another non-limiting embodiment, the metal product 42 includes an ingot, a billet, a bloom, a round bar, a square bar, an extrusion, a tube ( or consist of factory products, such as tubes, pipes, slabs, sheets, and plates. In another non-limiting embodiment, the metal product 42 is a metal alloy plate, the local area of the metal alloy plate is a linear region, and the forming step 36 removes the metal alloy plate in the linear region of the metal alloy plate. Bending.

Referring again to FIG. 4, in a non-limiting embodiment, the localized area 48 of the metal product 42 includes an area of the metal material immediately adjacent to the metal material to be plastically deformed during the forming step 36. In non-limiting embodiments, local area 48 is up to about 0.5 inches (1.27 cm), up to about 1 inch (2.54 cm), up to about 2 inches (5.04 cm), about 3 inches (7.62 cm) Up to about 4 inches (10.16 cm), or an area of metal material extending a greater distance away from the metal material of the product 42 to be plastically deformed during the forming step 36. In order to mold thicker product forms, it is envisaged that the area of the localized area can be increased to ensure that the area of the metal material undergoing plastic deformation during molding is at the desired bending temperature or other forming temperature.

In a non-limiting embodiment according to the invention involving indirect induction heating, the local region 48 of the metal product 42 is a linear region. In certain non-limiting embodiments using indirect induction heating, a linear region is an area that includes and surrounds a bend of the plate or other metal product to be bent, the linear area being along about all or part of the bend line. Up to 0.5 inches (1.27 cm), up to about 1 inch (2.54 cm), up to about 2 inches (5.04 cm), up to about 3 inches (7.62 cm), up to about 4 inches (10.16 cm), or sides of the bend Greater distances can be extended for either or both. It is also anticipated that the area of the linear region can be increased in order to bend thicker plates.

In a non-limiting embodiment that uses indirect induction heating to warmly form the metal product 42, the metal product 42 comprises a titanium alloy. In certain non-limiting embodiments, the titanium alloy is selected from ASTM grades 5, 6, 12, 19, 20, 21, 23, 24, 25, 29, 32, 35, 36, and 38 titanium alloys. .

In another non-limiting embodiment that uses indirect induction heating to warm form the metal product 42, the metal product comprises high hardness special steel. In a non-limiting embodiment, the metal product 42 is made of 400 BHN steel sheath alloy, 500 BHN steel sheath alloy, 600 BHN steel sheath alloy, 700 BHN steel sheath alloy, high strength low alloy steel, RHA alloy, HHA alloy, And materials selected from UHH alloys.

With particular reference to FIG. 4, a non-limiting aspect according to the present invention includes the use of indirect induction heating to bend a metal product within the construction of the plate 42. In a non-limiting embodiment, the local region 48 of the plate comprises a linear region, and the forming step 36 includes bending the plate in the linear region.

In non-limiting embodiments, the metal product 42 has a thickness of at least 0.125 inches (3.175 mm). In other non-limiting embodiments, the metal product 42 has a thickness of at least 0.1875 inches (4.763 mm).

In a non-limiting embodiment, when the metal material that includes the plate 42 is a Ti-4Al-2.5V-1.5Fe-0.25O ₂ titanium alloy (UNS 54250), the molding temperature range is from 728 ° F. to 874 ° F. 387 ° C. to 468 ° C.). In another non-limiting embodiment, when the metal material is a titanium alloy, the molding temperature range is from 700 ° F to 900 ° F.

In non-limiting embodiments, the local area 48 of the metal product 42 may have a bend radius of at least 1 t after the molding 36. In other non-limiting embodiments, the local region 48 of the metal product 42 may have a bending radius of at least 6t, at least 4t, or at least 2t after the forming 36.

In certain non-limiting embodiments, the metal product is a factory product. In another non-limiting embodiment, the metal product 42 is one of ingots, billets, blooms, round bars, horns, extrusions, tubes, pipes, slabs, plates, and plates.

A non-limiting aspect of the invention relates to a method for bending a metal plate using local indirect induction heating. Since the metal plate is one embodiment of a metal product, reference is again made to FIGS. 3 and 4. The method 30 and arrangement 40 for bending the metal plate 42 may include: placing 32 a metal plate 42 comprising a material selected from a metal and a metal alloy on the iron alloy surface 44; Induction heating of the linear surface area 46 of the iron alloy surface 44 in contact with the linear area 48 of the metal plate 42 to a predetermined temperature, thereby causing the linear area 48 of the plate 42 to be bent at a bending temperature. Conducting heating 34 to a bending temperature within a range; And bending 36 the plate 42 in the linear region 48.

Bending is one embodiment of molding. Thus, it is understood that all of the conditions described herein useful for local indirect induction heating for warm formed metal products apply equally to non-limiting embodiments of local indirect induction heating for warm bending of metal plates. Will be. In addition, the metal plates may include any of the metal materials specifically disclosed herein in various non-limiting embodiments and in other ways, wherein the plates may include various non- It may be processed by limited embodiments.

In a non-limiting embodiment, the metal plate 42 has a thickness of at least 0.125 inches (3.175 mm). In another non-limiting embodiment, the metal plate has a thickness of at least 0.1875 inches (4.763 mm).

One non-limiting aspect of the invention relates to a device for indirect local induction heating of articles comprising a metal material selected from metals and metal alloys. Referring now to FIG. 5, in a non-limiting embodiment, the device 60 includes a support 62 that includes an iron alloy surface 64, and at least one induction heating device 66. At least one induction heating device 66 is positioned and adapted to inductively heat a localized region 67 (bounded by lines 67a) of the iron alloy surface. FIG. 5 shows one induction heating device 66 used to heat a localized region 67 of the iron alloy surface 64, although more than one induction heating device 66 may have an iron alloy surface 64. It will be appreciated that it can be used to heat the local region 67 of. In addition, FIG. 5 shows a device for inductively heating a localized region 67 having a generally linear configuration, although the scope of the present invention is intended for inductively heated localized regions having different geometries and / or directions. It will be appreciated that it also includes changing the number, shapes, and / or positions of induction coils, and may be useful for various types of forming operations. In a non-limiting embodiment, the induction heated localized region of the iron alloy surface is adapted to conduct conductively heated to a predetermined temperature a localized region of the metal product comprising a material selected from a metal and a metal alloy located on the iron alloy surface. Is adapted.

In the forming operation, for example, when bending a metal plate or other metal product, the at least one induction heating device 66 inductively heats the localized region 67 of the iron alloy surface 64 to a predetermined temperature. Is activated to In a non-limiting embodiment, the predetermined temperature is the bending temperature of the metal or metal alloy plate or other article to be bent. The metal or metal alloy product (not shown) to be bent is placed in contact with the iron alloy surface 64. The local area of the metal or metal alloy plate in contact with the induction heated local area 67 of the iron alloy plate is, in a non-limiting embodiment, a predetermined temperature, which is the temperature at which the metal or metal alloy plate is bent. Conductive heating.

In a non-limiting embodiment, iron alloy surface 64 and support 62 comprise the same iron alloy. In another non-limiting embodiment, the iron alloy surface 64 and the support 62 are one piece, and the iron alloy surface 62 is the surface of the support 62. In one non-limiting embodiment, the support 62 includes at least one of an iron alloy plate and an iron alloy plate. In certain non-limiting embodiments, the iron alloy surface comprises a material selected from carbon steel, steel alloy, and stainless steel. In other non-limiting embodiments, the iron alloy surface 64 is the surface of the support 62, and the surface 64 and the support 62 are low carbon steel, steel alloy, and ferritic stainless steel. It is composed of at least one of the steel alloys.

In a non-limiting embodiment according to the invention, one or more of the induction heating devices 66 comprise one or more induction coils. In another non-limiting embodiment, one or more induction heating devices 66 are tuned to a frequency that engages a particular material of the iron alloy surface. For example, the iron alloy surface 64 may be composed of a steel alloy, and the frequency of the alternating magnetic field of the induction coil is adjusted to optimally heat the steel alloy. Tuning of induction coils for heating certain materials is known to those skilled in the art and need not be further detailed herein. In another non-limiting embodiment, the at least one induction heating device is located opposite the iron alloy surface 64 and is adapted to induction heating a linear region of the iron alloy surface 64.

In certain non-limiting embodiments, device 60 may be in the form of an induction heating table that includes legs 68. Also, optionally, the device insulates areas away from local area 67 to better include heating in local area 69 and to insulate water cooled induction coils 66. It may include an insulation 69.

One non-limiting aspect of the present invention relates to a device for direct induction heating of local regions of a metal plate or other metal product. Referring to FIG. 6, in a non-limiting embodiment, the device 70 includes a support 71 comprising a support surface 72, and at least one induction heating device 73. Support 71 and support surface 72 are constructed from one or more materials that are not induction heated by at least one induction heating device 73. For example, support 71 and support surface 72 are not electrically conductive and therefore may be constructed from one or more materials that cannot be heated using induction. In a non-limiting embodiment, the support 71 and the support surface 72 comprise a refractory material. As used herein, the term “refractory material” refers to non-having chemical and physical properties that allow them to withstand high temperatures, such as, for example, temperatures higher than 1000 ° F. (538 ° C.). Refers to metallic materials. Refractory materials that can be used when manufacturing the support 71 and the support surface 72 include, but are not limited to, aluminum oxide, silicon oxide, aluminosilicates, magnesium oxide ( magnesium oxide, zirconium oxide, calcium oxide, silicon carbide, fire clay, fire brick, magnesite ore, dolomite ore ore), chrome ore, and mixtures thereof. In a non-limiting embodiment, the support 71 and the support surface 72 comprise the same refractory material. However, it will be appreciated that the support 71 and the support surface 72 may comprise different refractory materials, or other suitable materials.

At least one induction heating device 73 inductively heats a localized area 74 (bounded by lines 74a) of the metal product 75 located on the support surface 72 of the support 71. Is positioned and adapted to. It is understood that the metal product 75 is not an element of the device 70 and is included in FIG. 6 to better illustrate the function of the device 70. FIG. 6 shows one induction heating device 73 for heating a localized area 74 of the metal product 75 disposed on the support surface 72, but more than one induction heating device 73 is shown. It will be appreciated that it may be used to heat the localized area 74 of the metal product 75 located on the support surface 72. In addition, although the non-limiting embodiment of FIG. 6 shows an induction coil 73 positioned under the support 71, in another non-limiting embodiment, at least one induction coil or other induction heating device ( 73 may be embedded in the support. 6 also shows a device for direct induction heating of local area 74 having a generally linear configuration, the scope of the present invention is direct induction heating of local areas with other geometries and / or directions. It will be appreciated that it may also be useful for various types of forming operations, including changing the number, shapes, and / or locations of induction coils in order to do so.

In a forming operation, such as, for example, bending a metal plate or other metal product, at least one induction heating device 73 of the device 70 may cause the localized region 74 of the metal product 75 to have a predetermined temperature. Activated to direct induction heating. In a non-limiting embodiment where the metal product 75 is a metal plate and the forming operation is a bending operation, the predetermined temperature is the bending temperature of the metal plate 75 within the bending temperature range.

In certain non-limiting embodiments where the induction heating device 73 is one or more water cooled induction coils, the device 70 may be in the form of an induction heating table that includes legs 76. Also, optionally, the device may include thermal insulation 77 to better include heating in local area 74 and to insulate the water-cooled induction coils 73.

With regard to various non-limiting embodiments of direct and indirect local induction heating according to the invention, the positioning of induction coils relative to the local area to be heated affects the temperature distribution in the local area to be heated. Will be understood. 7A and 7B are schematic representations of non-limiting embodiments of supports 62, 71 for a direct induction heating device 70 and an indirect induction heating device 60 for heating a local area of a metal product. admit. Supports 62 and 71 include surfaces 64 and 72 and opposing surfaces 80. In non-limiting embodiments of the device 60, 70, at least one induction coil 66, 73 may be located adjacent to the opposite surface. The non-limiting embodiment of FIGS. 7A and 7B shows portions 66, 73 of six induction coils, where the ends of each coil 66, 73 are connected to an electromagnet power supply. However, the illustrations of FIGS. 7A and 7B can also be interpreted to represent a non-limiting embodiment comprising one induction coil positioned adjacent to the opposite surface and having a serpentine shape. Only the outermost cross sections of the coils 66, 73 are connected to the electromagnet power supply. The bent cross-sections of the serpentine induction coil connecting the parts of the coils shown in FIGS. 7A and 7B are not shown in these figures.

In FIGS. 7A and 7B, the distance of at least one induction coil 66, 73 from the opposite surface is represented by arrow A. FIG. In a non-limiting embodiment, the distance A is about 0.5 inches (1.27 cm). The distance between the coils or the cross section of the at least one coil 66, 73 is represented by arrow B. In a non-limiting embodiment, the distance B is about 3 inches (7.62 cm). The thickness of the supports 62, 71 is represented by the arrow C. In a non-limiting embodiment, the distance C is about 1 inch (2.54 cm).

In a non-limiting embodiment of the devices 60, 70, the frequency and power of the electromagnet power supply are locally induced 67, or direct induction, of the ferroalloy surface 64 in the indirect induction heating device 60. It is selected to effectively heat the localized area 74 of the particular metal product 75 in the heating device 70. In a non-limiting embodiment of a direct induction heating device for heating titanium and titanium alloys, the electromagnet power supply can be operated at 150 KW and 1 KHz at about 6 KA.

Referring now to FIG. 8, another non-limiting aspect of the invention relates to a system for bending or otherwise forming a metal plate or other metal product comprising a material selected from metals and metal alloys. In a non-limiting embodiment, the system is positioned close to or adjacent to the heating device 60, 70, and the heating device, for example, as discussed in various non-limiting embodiments herein. Adapt to bending or otherwise forming a metal product along a linear or other local region (ie, in a linear or other local region) before the temperature in the linear or other local region cools below the desired temperature range. Bending device 80 or other forming device. In non-limiting embodiments, the heating device 60, 70 heats the linear or local region to a bending temperature or other molding temperature at the bending temperature or other molding temperature range. In a non-limiting embodiment, the bending or forming apparatus is located in proximity to the heating device and along the linear or other local region (ie, linear) before the linear or other local region cools below the bending or other forming temperature range. Or in other local areas) is adapted to bend or otherwise form the metal product.

Referring to FIG. 9, another aspect of the present invention relates to a molded ballistic face plate 90. In a non-limiting embodiment, the shaped ballistic shroud 90 according to the present invention has a thickness of “t” designated by arrows 92a and 92b and is approximately as shown by arrow 96. At least one bending area 94 having a bending radius of 2t. In non-limiting embodiments according to the present invention, the ballistic shroud 90 has a thickness "t" of at least 0.125 inches (3.175 mm), or at least 0.1875 inches (4.763 mm). 9 shows a molded ballistic sheath 90 having two bend regions 94 with a bend radius 96 of about 2 t, but with a different ratio of shaped ballistic sheath 90 according to the present invention. Limiting embodiments have at least one bend area 94 with a bend radius 96 of at least 1t, at least 2t, at least 4t, or at least 6t. In yet another embodiment, the shaped ballistic sheath comprises one of a titanium alloy, a nickel-based alloy, and special steel (eg, stainless steel, high-strength low-alloy steel (HSLA), sheath steel, etc.). In another non-limiting embodiment according to the present invention, the bent area 94 of the ballistic shroud 90 is free of surface defects, linear defect indications, and cracks.

Another aspect of the invention relates to an article of manufacture comprising one embodiment of the molded ballistic faceplate 90 of the present invention. According to certain non-limiting embodiments, the article of manufacture is a monolithic hull, V-type hull, explosion protection vehicle underbelly (for protection from mines and other explosion devices). Or a molded ballistic shroud 90 in the form of one of an enclosure for explosion protection.

Several examples illustrating specific non-limiting embodiments in accordance with the present invention are as follows.

Example 1

The induction heating device was configured in the form of an induction heating table. A picture of the heating table is provided in FIG. 10. A steel alloy plate with a thickness of 0.5 inch (1.27 cm) was used as the support and iron alloy surface. The legs are welded to the steel plate to support the plate. The copper induction coil is located on the underside of the steel alloy plate and has been adapted to heat the linear region of the steel alloy plate and thereby to heat the iron alloy surface of the steel alloy plate. Induction coils were activated with RF power transformers using frequencies suitable for heating iron alloys such as steel alloys of steel alloy plates. Induction heating devices can be used to conduct conductive heating of localized areas of metal plates and other products including refractory metal materials and other metal materials. The conductive heated forms may then be bent or otherwise molded, for example, as discussed herein with various embodiments.

Example 2

Plates of the ATI 425 ^® titanium alloy (Ti-4Al-2.5V-1.5Fe-0.25O ₂ alloy, UNS R54250) with a thickness of 1 inch (2.54 cm) are manufactured by Allegheny Technologies Incorporated company, Albany OR (Albany OR), obtained from ATI Wah Chang. The plate was hot rolled through conventional factory conventions and received in a factory-annealed state. The plate was cut into 12 inch x 30 inch samples. The induction heating table described in Example 1 was configured such that the local linear region of the iron alloy surface was induction heated to a temperature of 800 ° F. (428 ° C.). Titanium alloy plates samples were placed sequentially on the induction table such that the intended bend line of each sample was located above the heated localized area of the induction heating table, whereby the local area of each sample was conductively heated. More specifically, the linear region of each sample, including the intended bend and immediately adjacent regions, was electrically heated to 800 ° F. (428 ° C.) in about 12 minutes through contact with the iron alloy surface. Before any significant cooling occurred, the samples were bent along a heated bent line on the brake press located near the induction heating table. Samples were bent to increasing radii of 1t to 6t. The bent sample is shown in the photograph of FIG. 11.

The bent samples were examined to assess the condition of the bend area of each sample. No surface defects, linear defect indications, or cracks were observed in the bent regions.

Example 3

An ATI 425 ^® titanium alloy sheet having a thickness of 1 inch (2.54 cm) in the same factory-annealed state as used in Example 2 was obtained from ATI Wah Chang. The length and width of the plate was 100 inches (2.54 m) x 80 inches (2.032 m). The plate was placed on the induction heating table described in Example 1, and the linear region of the plate, including the intended bend and adjacent regions, was electrically heated to 800 ° F. (426 ° C.) in about 20 minutes. The plate was transferred to the brake press before the heated linear region of the plate experienced any significant cooling and the plate was bent at a radius of 2t along the bend line. The plate was placed back on the induction heating table and arranged so that different linear regions including another intended bend line were electrically heated to 850 ° F. (454.4 ° C.). The plate was then delivered to the brake press and bent along the bending line with a radius of 2t before any significant cooling of the linear region occurred. This process was repeated until the plate was bent at a 2t radius at six different positions. No surface defects or cracks were observed in the six bent regions.

Example 4

The plate is generally molded using the process described in Example 3 to include one or more bends. The plate is for example Ti-4Al-2.5V-1.5Fe-0.25O ₂ alloy, another titanium alloy, or for example 500 BHN steel sheath alloy, 600 BHN steel sheath alloy, 700 BHN steel sheath alloy, high It may be composed of a sheath alloy, such as low strength steel, RHA alloy, HHA alloy, or UHH alloy. The molded plate is welded to the chassis of an exterior or other vehicle. The shaped plate acts as a ballistic faceplate underbell for the vehicle. The shape, direction, and / or composition of the shaped plate is adapted to dissipate the explosive energy generated by the explosive devices exploded under the vehicle.

Example 5

The local area of the 84-inch (215.9 cm) long, 1-inch (2.54 cm) thick ATI 425 ^® titanium alloy plate is a direct local induction heating device, as disclosed herein and as shown in FIG. 6. Direct induction heating was performed using non-limiting examples. As shown in FIG. 7, the induction heating device included a serpentine-type induction coil located at about 0.5 inches (1.27 cm) from the refractory support with six cross sections spaced apart in a plane about 3 inches (7.62 cm) apart. . The thickness of the refractory support was about 1 inch (2.54 cm). Induction coils were activated at 150 KW, 1 KHz, and 1 A for 900 seconds. Thereafter, power to the induction coil was cut off and the plates were allowed to air cool. The top and bottom temperatures of the plate were measured after 900 seconds of local induction heating and after 60 seconds of air cooling as a function of distance from the centerline of the heated zone. 12 includes a plot of the measured temperatures of the top and bottom of the plate after heating and after cooling for 60 seconds. The temperature of the top and bottom of the plate in the central region of the heated zone ranged from about 1200 ° F. (648.9 ° C.) to about 900 ° F. (482 ° C.) after 900 seconds of induction heating, with the heated zone being the bent plate area. About 11 inches (27.94 cm) on each side of the centerline. After cooling in ambient air for about 60 seconds, the temperature in the central region of the heated zone ranged from about 900 ° F. (482 ° C.) to about 1000 ° F. (537.8 ° C.), which caused the plate to be bent or otherwise formed. It is a temperature range that can be.

It will be understood that the present description illustrates these aspects of the invention in connection with the clear understanding of the invention. Certain aspects that are apparent to those skilled in the art and, therefore, will not enable a better understanding of the present invention have not been provided to simplify the present description. Although only a limited number of embodiments of the present invention are necessarily described herein, one of ordinary skill in the art will recognize that many modifications and variations of the present invention can be used, given the foregoing description. . All such variations and modifications of the invention are intended to be covered by the foregoing description and the following claims.

Claims (84)

Inductively heating a localized region of a metal product to a forming temperature, the forming temperature being in a forming temperature range of 0.20 to 0.50 of the melting temperature of the material Making; And
Forming the metal product in the local area. The method according to claim 1,
Forming the metal product comprises at least one of bending, drawing, punching, stamping, and roll forming. The method according to claim 1,
The metal product may be a titanium alloy, a nickel-base alloy, a stainless steel alloy, a high-strength low-alloy steel, and A method of forming a metal product, comprising a material selected from an armor steel alloy. The method according to claim 1,
The metal product may include an ingot, a billet, a bloom, a round bar, a square bar, an extrusion, a tube, a pipe, a pipe0, and a slab. , A sheet, and a plate. The method according to claim 1,
The metal product is a plate, the local area comprises a linear area, and forming the metal product comprises bending the metal product in the linear area. The method according to claim 1,
And the metal article comprises a titanium alloy. The method according to claim 1,
The metal product comprises a material selected from the group consisting of ASTM Grades 5, 6, 12, 19, 20, 21, 23, 24, 25, 29, 32, 35, 36, and 38 titanium alloys. Comprising a method of molding a metal product. The method according to claim 1,
And the metal product comprises specialty steel. The method according to claim 1,
The metal product comprises a material selected from 500 BHN steel sheath, 600 BHN steel sheath, 700 BHN steel sheath, high strength low alloy steel, RHA alloy, HHA alloy, and UHH alloy. The method according to claim 1,
And the metal product comprises a nickel-based alloy. The method according to claim 1,
And wherein the metal article has a thickness of at least 0.125 inches (3.175 mm). The method according to claim 1,
Wherein the metal article has a thickness of at least 0.1875 inches (4.763 mm). The method according to claim 1,
The metal article comprises a Ti-4Al-2.5V-1.5Fe-0.25O ₂ titanium alloy (UNS 54250) and the forming temperature range is from 728 ° F. to 874 ° F. (387 ° C. to 468 ° C.). How to. The method according to claim 1,
Wherein said metal product comprises a titanium alloy and said forming temperature range is from 700 ° F to 900 ° F. The method according to claim 1,
Induction heating the local region comprises heating the local region to a temperature in the molding temperature range with at least one induction heater. The method according to claim 1,
Forming the metal product in the local area comprises bending the metal product in the local area with a radius of at least 2 t. The method according to claim 1,
Molding the metal product in the local area comprises bending the metal product in the local area with a radius of at least 1 t. The method according to claim 1,
After the forming, the local area of the metal product is free of linear indications and cracks. Induction heating a linear region of a metal plate to a bending temperature, wherein the bending temperature is in a bending temperature range of 0.2 to 0.5 of a melting temperature of the metal plate; And
Bending the metal plate in the linear region. The method of claim 19,
And said metal plate comprises a material selected from titanium alloys, nickel-based alloys, stainless steel alloys, high-strength low-alloy steels, and sheath steel alloys. The method of claim 19,
And said metal plate comprises a titanium alloy. The method of claim 19,
The metal plate comprises a metal plate comprising a material selected from the group consisting of ASTM grades 5, 6, 12, 19, 20, 21, 23, 24, 25, 29, 32, 35, 36, and 38 titanium alloys. How to bend. The method of claim 19,
And said metal plate comprises a special steel. The method of claim 19,
The metal plate bends the metal plate, comprising a material selected from 400 BHN steel sheath, 500 BHN steel sheath, 600 BHN steel sheath, 700 BHN steel sheath, high strength low alloy steel, RHA alloy, HHA alloy, and UHH alloy. Way. The method of claim 19,
And the metal plate has a thickness of at least 0.125 inches (3.175 mm). The method of claim 19,
And the metal plate has a thickness of at least 0.1875 inches (4.763 mm). The method of claim 19,
The metal plate includes a Ti-4Al-2.5V-1.5Fe-0.25O ₂ titanium alloy (UNS 54250) and the bending temperature range is 728 ° F. to 874 ° F. (387 ° C. to 468 ° C.). Way. The method of claim 19,
Wherein said metal plate comprises a titanium alloy and said bending temperature range is from 700 ° F to 900 ° F. The method of claim 19,
Inductively heating the linear region comprises heating the linear region to a temperature in the bending temperature range with at least one induction heater. The method of claim 19,
Bending the metal plate in the linear region comprises bending the metal plate in the linear region with a radius of at least 2 t. The method of claim 19,
Bending the metal plate in the linear region comprises bending the metal plate in the linear region with a radius of at least 1 t. The method of claim 19,
After said forming, said localized region of said metal product is free of linear defect indications and cracks. Placing a metal product comprising a material selected from a metal and a metal alloy on the iron alloy surface;
Induction heating of a localized area of the iron alloy surface in contact with a localized area of the metal product to a predetermined temperature, thereby conductively heating the localized area of the metal product to a forming temperature within a forming temperature range. ); And
Forming the metal product in the local region of the metal product. 34. The method of claim 33,
Wherein the metal product comprises a material selected from titanium alloys, nickel-based alloys, stainless steel alloys, high-strength low-alloy steels, and sheath steel alloys. 34. The method of claim 33,
Wherein the forming temperature range is from 0.2 to 0.5 of the melting temperature of the metal material. 34. The method of claim 33,
And the metal article comprises a titanium alloy. 34. The method of claim 33,
The metal product comprises a material selected from the group consisting of ASTM grades 5, 6, 12, 19, 20, 21, 23, 24, 25, 29, 32, 35, 36, and 38 titanium alloys. How to mold the product. 34. The method of claim 33,
And the metal product comprises a nickel-based alloy. 34. The method of claim 33,
Wherein the metal product comprises a special steel. 34. The method of claim 33,
The metal product comprises a metal product comprising a material selected from 400 BHN steel sheath, 500 BHN steel sheath, 600 BHN steel sheath, 700 BHN steel sheath, high strength low alloy steel, RHA alloy, HHA alloy, and UHH alloy. How to mold. 34. The method of claim 33,
Wherein the metal product is a plate, the local area comprises a linear area, and forming the metal product in the local area comprises bending the plate in the linear area. Way. 34. The method of claim 33,
And the metal article has a thickness of at least 0.125 inch (3.175 mm). 34. The method of claim 33,
Wherein the metal article has a thickness of at least 0.1875 inches (4.763 mm). 34. The method of claim 33,
The metal article comprises a Ti-4Al-2.5V-1.5Fe-0.25O ₂ titanium alloy (UNS 54250) and the forming temperature range is from 728 ° F. to 874 ° F. (387 ° C. to 468 ° C.). How to. 34. The method of claim 33,
Wherein said metal product comprises a titanium alloy and said forming temperature range is from 700 ° F to 900 ° F. 34. The method of claim 33,
Inductively heating the localized region of the iron alloy surface comprises heating the localized region of the iron alloy surface with at least one induction heater. 34. The method of claim 33,
Forming the metal product in the local area comprises bending the metal product in the local area with a radius of at least 2 t. 34. The method of claim 33,
Molding the metal product in the local area comprises bending the metal product in the local area with a radius of at least 1 t. 34. The method of claim 33,
After said forming, said localized area is free of linear defect indications and cracks. 34. The method of claim 33,
And said metal product is selected from ingots, billets, blooms, round bars, angles, extrusions, tubes, pipes, slabs, sheet materials, and plates. Placing a metal plate comprising a material selected from a metal and a metal alloy on the iron alloy surface;
Inductively heating the linear region of the iron alloy surface in contact with the linear region of the metal plate to a predetermined temperature, thereby electrically conducting heating the linear region of the metal plate to a bending temperature within a bending temperature range; And
Bending the metal plate in the linear region of the metal plate. 54. The method of claim 51,
And said bending temperature range is from 0.2 to 0.5 of the melting temperature of said material. 54. The method of claim 51,
And the metal plate comprises a material selected from titanium alloys, nickel-based alloys, stainless steel alloys, high-strength low-alloy steels, and sheath steel alloys. 54. The method of claim 51,
And said metal plate comprises a titanium alloy. 54. The method of claim 51,
The metal plate comprises a metal plate comprising a material selected from the group consisting of ASTM grades 5, 6, 12, 19, 20, 21, 23, 24, 25, 29, 32, 35, 36, and 38 titanium alloys. How to bend. 54. The method of claim 51,
And said metal plate comprises a nickel-based alloy. 54. The method of claim 51,
And said metal plate comprises a special steel. 54. The method of claim 51,
And the metal plate comprises a material selected from 500 BHN steel sheath, 600 BHN steel sheath, 700 BHN steel sheath, high strength low alloy steel, RHA alloy, HHA alloy, and UHH alloy. 54. The method of claim 51,
And the metal plate has a thickness of at least 0.125 inches (3.175 mm). 54. The method of claim 51,
And the metal plate has a thickness of at least 0.1875 inches (4.763 mm). 54. The method of claim 51,
The metal plate comprises a Ti-4Al-2.5V-1.5Fe-0.25O ₂ titanium alloy (UNS R54250), wherein the bending temperature range is 728 ° F. to 874 ° F. (387 ° C. to 468 ° C.). Way. 54. The method of claim 51,
Wherein said metal plate comprises a titanium alloy and said bending temperature range is from 700 ° F to 900 ° F. 54. The method of claim 51,
Inductively heating the linear region of the iron alloy surface comprises heating the linear region of the iron alloy surface with at least one induction heater. 54. The method of claim 51,
Bending the metal plate in the linear region comprises bending the metal plate in the linear region with a bending radius of at least 2 t. 54. The method of claim 51,
Bending the metal plate in the linear region comprises bending the metal plate in the linear region with a bending radius of at least 1 t. 54. The method of claim 51,
After the bending, the linear region is free of linear defect indications and cracks. A device for local heating of a metal product comprising a material selected from a metal and a metal alloy, the device comprising:
A support comprising an iron alloy surface; And
At least one induction heating device,
The at least one induction heating device is positioned and adapted to inductively heat a localized area of the iron alloy surface,
The induction heated localized region of the iron alloy surface is adapted to heat a localized region of the metallic product comprising a material selected from a metal and a metal alloy located on the iron alloy surface to a predetermined temperature. Device for local heating of the device. 68. The method of claim 67,
And the support comprises at least one of an iron alloy sheet comprising the iron alloy surface, and an iron alloy plate comprising the iron alloy surface. 65. The method of claim 67,
And the iron alloy surface comprises a steel alloy surface. 65. The method of claim 67,
And the iron alloy surface comprises one or more materials selected from carbon steel, steel alloy, and stainless steel. 65. The method of claim 67,
The at least one induction heating device is tuned to inductively heat a predetermined localized area of the iron alloy surface. 65. The method of claim 67,
The at least one induction heating device is disposed opposite the iron alloy surface and is adapted to inductively heat a predetermined linear region of the iron alloy surface. A device for local heating of a metal product comprising a material selected from a metal and a metal alloy, the device comprising:
A support comprising a support surface; And
At least one induction heating device,
The at least one induction heating device is positioned and adapted to inductively heat a localized region of a metal product, and is located on the support surface at a predetermined temperature,
And the support and the support surface comprise a material that is not heated by the at least one induction heating device. The method of claim 73, wherein
And the support and the support surface comprise a refractory material. The method of claim 73, wherein
The support and the support surface, aluminum oxide (silicon oxide), silicon oxide (silicon oxide), aluminosilicate (aluminosilicate), magnesium oxide (magnesium oxide), zirconium oxide, calcium oxide (calcium oxide), carbide Metal products, including one or more of silicon carbide, fire clay, fire brick, magnesite ore, dolomite ore, and chrome ore Device for local heating. The method of claim 73, wherein
Wherein the frequency of the at least one induction coil is tuned for heating of the material comprising the metal product. 78. The method of claim 76,
Wherein said particular metal alloy is a titanium alloy and said frequency of said induction coil is tuned to 1 KHz. A system for bending a metal product comprising a material selected from a metal and a metal alloy, the system comprising:
A support comprising an iron alloy surface, and
At least one induction heating device,
The at least one induction heating device is positioned and adapted to inductively heat a predetermined linear region of the iron alloy surface,
The induction heated linear region of the iron alloy surface includes the at least one induction heating device adapted to conduct conductive heating of a linear region of a metal product located on the iron alloy surface to a bending temperature in a bending temperature range. A heating device; And
A metal material bending device positioned in proximity to the iron alloy surface and adapted to bend the metal product in the linear region before the linear region cools below the bending temperature range. . A system for bending a metal product comprising a material selected from a metal and a metal alloy, the system comprising:
A support comprising a support surface, and
At least one induction heating device,
The at least one induction heating device is positioned and adapted to inductively heat a localized region of a metal product located on the support surface to a bending temperature in a bending temperature range,
The support and the support surface comprise a heating device comprising the at least one induction heating device, the material comprising material not heated by the at least one induction heating device; And
Bending a metal product, said metal material bending device being positioned in proximity to said support and said support surface and adapted to bend said metal product in said linear region before said linear region cools below said bending temperature range. System. At least one of titanium alloys, nickel-based alloys, and special steel alloys, stainless steel alloys, high-strength low-alloy steel (HSLA), and sheath steel alloys; And
A molded ballistic armor plate comprising at least one bending area having a bending radius of at least 2 t. The method of claim 80,
And wherein the molded ballistic sheath has a thickness of at least 0.125 inches (3.175 mm). The method of claim 80,
And wherein the molded ballistic sheath has a thickness of at least 0.1875 inches (4.763 mm). The method of claim 80,
Wherein the molded ballistic face plate is one of a monolithic hull, a V-shaped hull, an explosion protection vehicle underbelly, and an enclosure. 84. An article of manufacture comprising the molded ballistic faceplate of any one of claims 80-83.

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