DESC:TECHNICAL FIELD
[0001] The present disclosure relates generally to the field of manufacturing. In particular, the present disclosure relates to a simple, compact, and efficient system and method for manufacturing of Inconel flanges that are fabricated between the temperature range between 900 °C to 1200 °C where the Inconel is preferably an Inconel 718 but not limited to Inconel 718 including any Inconel alloys for example, Inconel Alloy 625 and Inconel Alloy 600.

BACKGROUND
[0002] Conventionally known Inconel is a nickel-chromium-based superalloy often utilized in extreme environments where components are subjected to high temperature, pressure or mechanical loads. Inconel alloys are oxidation and corrosion-resistant; when heated, Inconel forms a thick, stable, passivating oxide layer protecting the surface from further attack. Inconel retains strength over a wide temperature range, attractive for high-temperature applications where aluminum and steel would succumb to creep as a result of thermally-induced crystal vacancies. Inconel's high-temperature strength is developed by solid solution strengthening or precipitation hardening, depending on the alloy. Inconel alloys are typically used in high temperature applications.
[0003] Inconel 718 is a high-performance nickel-based super alloy renowned for its exceptional mechanical properties and corrosion resistance in extreme environments. Composed primarily of nickel, chromium, and iron, with additions of niobium, molybdenum, aluminum, titanium, and other elements, it exhibits remarkable strength, creep resistance, and oxidation resistance at elevated temperatures, making it suitable for gas turbines, rocket motors, spacecraft, nuclear reactors, pumps, and tooling applications. Inconel 718's unique combination of properties stems from its intricate precipitation-hardened microstructure, which is carefully controlled through heat treatments. Its ability to maintain its integrity in demanding conditions, coupled with its weldability and machinability, has solidified its position as a vital material in industries requiring reliability and performance under challenging circumstances.
[0004] However, there are some challenges associated with its forging process. Forging Inconel alloys poses challenges due to their high strength, complex microstructure, and sensitivity to temperature variations. Issues include cracking from microstructural segregation, work hardening affecting deformability, oxidation at elevated temperatures, potential grain growth compromising mechanical properties, tool wear due to alloy toughness, dimensional inconsistency from uneven deformation, and residual stresses affecting part integrity. Effective process control, proper tooling, and precise temperature management are vital to successful Inconel forging. Addressing these challenges requires a comprehensive understanding of Inconel 718's metallurgy, thorough process optimization, and the utilization of advanced forging techniques. Collaboration between metallurgists, material scientists, and manufacturing engineers is essential to successfully forge high-quality Inconel 718 components while minimizing these potential issues.
[0005] To achieve tolerances, specific grain structures, and desired properties of the final product, Conventionally, it is manufactured by Isothermal forging. In this forging method, the workpiece is heated to a constant temperature and maintained at that temperature throughout the forging process. However isothermal forging process have the following drawbacks:
Equipment and Energy Costs: Isothermal forging requires specialized equipment like isothermal furnaces or induction heating systems to maintain a constant and precise temperature. These systems can be expensive to install and operate.
Material Wastage: In isothermal forging, material is heated to a specific temperature and held there for an extended period. This can result in more significant material wastage due to the need to trim excess material or remove surface defects caused by oxidation or scaling during heating.
Complex Process Control: Isothermal forging demands precise temperature control throughout the entire process. Any deviations in temperature can lead to defects such as cracking or uneven grain structures in the final product. This level of control requires advanced monitoring and feedback systems, which can be complex and costly to implement.
Slower Production Rates: Due to the careful temperature control and longer processing times, isothermal forging processes are generally slower. This can impact the overall production rate and lead to increased lead times for large orders.
Tooling and Die Wear: Isothermal forging exposes tooling and dies to high temperatures for longer durations, accelerating wear and reducing their lifespan. This can result in higher maintenance costs and more frequent tool replacements.
Material Segregation: Inconel alloys are known to be sensitive to segregation, where the distribution of alloying elements becomes uneven during the forging process. Isothermal forging's prolonged exposure to high temperatures can exacerbate this issue, leading to material inconsistencies in the final product.
Limited Applicability: Isothermal forging is typically reserved for applications where precise temperature control and specific grain structures are crucial.
[0006] For more straightforward or high-volume forging tasks, press forging is often a more practical and cost-effective choice. It is also manufactured by hammer forging method by applying multiple blows or strokes as shown in FIG. 2A. However, hammer forging has many
drawbacks, which are as follows:
Low productivity: Cycle time for hammer forging is very high due to multiple blows requirement. Thus; the productivity of this process is low.
Non-uniform microstructure: Multiple heats and booster heats are required during the aforementioned steps to manufacture one part in hammer forging. It leads to the coarsening of the microstructure as well as the non-uniform microstructure in the finished part. This has a significant effect on the mechanical properties of the part and may render the part unsuitable for the intended purpose. Further, the presence of non-uniform microstructure leads to flow localization and crack formation in the finisher stage.
Uneven strain penetration: The deformation in each stroke of the hammer is very small. Due to this the deformation or strain does not penetrate throughout the whole part. This leads to non-uniform consolidation and microstructure.
Dimensional Accuracy: Achieving precise dimensional tolerances on flanges can be challenging due to the rapid and forceful nature of hammer forging. Variations in die wear, material flow, and hammer impacts can lead to inconsistencies in flange dimensions.
Material Flow Control: Controlling the material flow during hammer forging is crucial to avoid defects like incomplete fills, under-fills, or excessive flash.
Die Wear and Maintenance: The repetitive and high-impact nature of hammer forging can lead to rapid wear of the forging dies, affecting product quality and dimensional accuracy.
Energy Consumption and Efficiency: Hammer forging can be energy-intensive, impacting production costs and environmental considerations. Finding ways to optimize forging processes and minimize energy consumption is important for sustainable manufacturing.
One of the ways to overcome the abovementioned drawbacks of the conventional hammer forging method is by producing the Inconel 718 Flange on a forging press. The aforementioned drawbacks are as follows:
Productivity: It is possible to give bigger deformations in the press because forging presses have higher energy and force capacity than a forging hammer. It leads to reduce the number of strokes required for deforming the billet to the final shape of the flange. This results in the time required to produce the final product being drastically less than the conventional method.
Uneven strain penetration: Greater deformation in each stroke helps in better penetration of strain throughout the part. This helps in the uniform consolidation of the part, and thus, rather desirably, uniform properties.
Non-uniform microstructure: Use of slow strain rate equipment such as a hydraulic press or a screw press in combination with applying higher deformation (than conventional methods) per step helps in uniform deformation of the material throughout the part, and hence, produces more uniform microstructure in the part. As compared to the conventional methods, a lesser number of heats and booster heats are required when producing the part on the forging press. This further helps the uniformity of the microstructure.
[0007] However, forging Inconel flanges on a press involves its own set of challenges. Some problems associated with Inconel flange forging on a press include:
Press Capacity: To deform Inconel alloy, very high forces are required. Forging presses to carry out conventional methods deploying the steps of upsetting, buster forging, and finisher forging, one would need to use very high-capacity forging presses.
Energy Consumption: Forging Inconel flanges on a press might require higher pressures/force and energy consumption compared to other materials, affecting both production costs and environmental considerations.
Residual Stresses and Distortion: The high deformation forces involved in pressing can induce residual stresses and cause distortion, particularly in thick or complex flange sections.
Rate of Deformation: Inconel's work hardening behavior can impact the rate of deformation and require careful control to avoid excessive strain rates that could lead to cracking or other defects.
Die Filling and Material Flow: Inconel's high strength and resistance to deformation can lead to difficulties in achieving complete die-filling and uniform material flow, especially in complex or intricate flange geometries.
Die Wear and Maintenance: Inconel's abrasive nature can accelerate die wear, requiring frequent maintenance or replacement of forging dies, which can impact production efficiency and cost.
Heating and Temperature Control: Inconel's sensitivity to temperature variations demands precise heating and temperature control to maintain optimal forging conditions and prevent issues like cracking or improper deformation.
[0008] Thus, there exists room for advancement over the existing technology in that a method of manufacturing has to be designed to suit the manufacturing of Inconel flanges (specifically Inconel 718 flange) through a hot forging process on a combination of a forging press and ring rolling. Thus, reducing manufacturing cycle time and improving the mechanical and metallurgical properties of the part.

OBJECTIVES OF THE PRESENT DISCLOSURE
[0009] A general objective of the present disclosure is to overcome the problems associated with existing manufacturing process, by providing a simple, compact, efficient, and cost-effective a system and method for manufacturing of Inconel flanges that are fabricated between the temperature range between 900 °C to 1200 °C.
[0010] An objective of the present disclosure is to achieve uniform deformation and microstructure in the Inconel flange by slow strain rate.
[0011] Another objective of the present disclosure is to ensure that the final Inconel flanges have a uniform microstructure with an effective strain up to 2.5 and near-zero shear bands and cracks.
[0012] Yet another objective of the present disclosure is to provide a ring rolling and closed die hot forging process for Inconel flange that ensures uniform grain flow and eliminates material defects.

SUMMARY
[0013] Aspects of the present disclosure pertain to the field of manufacturing. In particular, the present disclosure relates to a simple, compact, and efficient system and method for manufacturing of Inconel flanges that are fabricated between the temperature range between 900 °C to 1200 °C.
[0014] According to an aspect, the disclosed method for manufacturing an Inconel flange includes a step of first forging a heated upset preform to form a first doughnut preform using a forging press and another step of first heating the first doughnut preform to a second predefined temperature using a furnace to form a first heated first doughnut preform. A top die and a bottom die of the forging press at a first predefined temperature forges a profile over the heated upset preform during first forging. Additionally, the method includes a step of second forging the first heated first doughnut preform to form a second doughnut preform using the forging press and punching and another step of piercing the second doughnut preform for removing a central portion from the second doughnut preform to form a pierced second doughnut preform. A die profile of the top die and bottom die at the first predefined temperature prevents machined off material coming into contact between the top die and the bottom die such that the machined off material is deformed in a reverse extrusion manner , enabling the forging press to use a low load for forming second forging operation on the first heated first doughnut preform.
[0015] Further, the method includes a step of second heating the pierced second doughnut preform to the second predefined temperature using the furnace forms a second heated pierced doughnut preform. The method includes a step of ring rolling the second heated pierced doughnut preform to form a ring and another step of machining to split the ring into three parts, forming three split rings. A king roll and a mandrel of the ring roller are maintained at the first predefined temperature during ring rolling.
[0016] Furthermore, the method includes a step of third heating each of the three split rings to the second predefined temperature using the furnace forms a third heated split ring and another step of finishing the third heated split ring using the forging press to achieve final dimensions of the flange having one or more thin sections, a deep cavity and a shallow cavity. A top die and a bottom die of the forging press maintained at a first predefined temperature, allows unrestricted material flow in one or more grooved portions in the inner and outer diameters between the top die and the bottom die and at least one height in the bottom die, forms the Inconel flange with a uniform microstructure having an effective strain up to 2.5 and near zero shear bands and cracks.
[0017] In an embodiment, the method may include a pre-step of slicing a raw Inconel to obtain a cylindrical billet and another pre-step of heating the sliced cylindrical billet to the second predefined temperature using the furnace forms a heated cylindrical billet. In addition, the method may include a step of deforming the heated cylindrical billet to form an upset preform using the top die and the bottom die at the first predefined temperature. The upset preform may be achieved in a single stroke of the forging machine. Further, the method may include a pre-step of reheating the upset preform to the second predefined temperature after being cooled to a third predefined temperature using the furnace forms the heated upset.
[0018] In an embodiment, the first predefined temperature may be selected between a temperature range between 250°C to 300°C and the second predefined temperature may be selected between a temperature range between 1000°C to 1025°C.
[0019] In an embodiment, the preformed Inconel flange may be cooled to the third predefined temperature before first heating, second heating, third heating, and finishing. The third predefined temperature may be selected from a temperature range between 20°C to 30°C.
[0020] In an embodiment, the method may include a step of solution treating the finished flanges at a temperature range between 940°C to 970°C for 1.5 hours followed by oil quenching.
[0021] In an embodiment, the method includes a step of first precipitation treating the solution-treated flanges at a temperature range between 710°C to 730°C for 8 hours followed by furnace cooling the first precipitation-treated flange.
[0022] In an embodiment, the method may include a further step of solution-second precipitation treating, the first precipitation treated flanges at a temperature range between 610°C to 630°C for 8 hours followed by air cooling the second precipitation-treated flange.
[0023] According to an aspect, the disclosed system for manufacturing an Inconel flange includes a forging press having a top die and a bottom die adapted to generate heat to a temperature range between 250°C to 300°C. The forging press is configured to move towards and away from a raw Inconel flange. The Inconel flange is positioned between the top die and the bottom die such that a finish die profile of the top die and bottom die is forged on the raw Inconel flange. The finish die profile provides one or more cavities in the inner and outer diameters between the top die and the bottom die and at least one groove in the bottom die for preventing removed material from the raw Inconel flange from coming into contact between the top die and the bottom die enabling the forging press to use low load during forging operation.
[0024] In addition, the system includes a furnace configured for heating the raw Inconel flange to a temperature range between 1000°C to 1025°C. The furnace may be selected from an electric furnace and a gas furnace. Further, the system includes a ring roller includes a king roll and a mandrel adapted to generated heat at a temperature range between 250°C to 300°C. The ring roller may be configured to perform a rolling operation on the raw Inconel flange. The system forms the Inconel flange with a uniform microstructure having an effective strain up to 2.5 and near zero shear bands and cracks.
[0025] Various objects, features, aspects, and advantages of the subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF DRAWINGS
[0026] The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure. The diagrams are for illustration only, which thus is not a limitation of the present disclosure.
[0027] FIG. 1 illustrates a schematic view of an Inconel flange profile, in accordance with one embodiment of the present invention.
[0028] FIG. 2A illustrates a flow diagram showing a convention manufacturing process of the Inconel flange, in accordance with an embodiment of the present invention.
[0029] FIGs. 2B-2C illustrates another flow diagram showing a forging process of manufacturing of Inconel flange, in accordance with one embodiment of the present invention.
[0030] FIGs. 2D illustrates another flow diagram showing a method of manufacturing the Inconel flange, in accordance with one embodiment of the present invention.
[0031] FIG. 3A illustrates a design of a conventional doughnut used in manufacturing of Inconel flange, in accordance with one embodiment of the present invention.
[0032] FIG. 3B illustrates a design of a doughnut used in forging process of manufacturing of Inconel 718 flange, in accordance with one embodiment of the present invention.
[0033] FIG. 4A illustrates a design of a conventional Finisher used in manufacturing of Inconel flange, in accordance with one embodiment of the present invention.
[0034] FIG. 4B illustrates a design of a Finisher used in forging process of manufacturing of Inconel flange, in accordance with one embodiment of the present invention.
[0035] FIG. 5 illustrates a microstructure obtained by a forging process of manufacturing of Inconel flange, in accordance with one embodiment of the present invention.
[0036] FIGs. 6A-6B illustrates a table below showing a clear difference between the steps of the conventional forging method that are used in the process, in accordance with one embodiment of the present invention.
[0037] FIG.7 illustrates a block diagram showing different components of a system for manufacturing the Inconel flange, in accordance with one embodiment of the present invention.

DETAILED DESCRIPTION
[0038] For the purpose of promoting an understanding of the principles of the present disclosure, reference will now be made to the various embodiments and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the present disclosure is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the present disclosure as illustrated therein being contemplated as would normally occur to one skilled in the art to which the present disclosure relates.
[0039] It will be understood by those skilled in the art that the foregoing general description and the following detailed description are explanatory of the present disclosure and are not intended to be restrictive thereof.
[0040] Whether or not a certain feature or element was limited to being used only once, it may still be referred to as “one or more features” or “one or more elements” or “at least one feature” or “at least one element.” Furthermore, the use of the terms “one or more” or “at least one” feature or element do not preclude there being none of that feature or element, unless otherwise specified by limiting language including, but not limited to, “there needs to be one or more…” or “one or more elements is required.
[0041] Reference is made herein to some “embodiments.” It should be understood that an embodiment is an example of a possible implementation of any features and/or elements of the present disclosure. Some embodiments have been described for the purpose of explaining one or more of the potential ways in which the specific features and/or elements of the proposed disclosure fulfil the requirements of uniqueness, utility, and non-obviousness.
[0042] Use of the phrases and/or terms including, but not limited to, “a first embodiment,” “a further embodiment,” “an alternate embodiment,” “one embodiment,” “an embodiment,” “multiple embodiments,” “some embodiments,” “other embodiments,” “further embodiment”, “furthermore embodiment”, “additional embodiment” or other variants thereof do not necessarily refer to the same embodiments. Unless otherwise specified, one or more particular features and/or elements described in connection with one or more embodiments may be found in one embodiment, or may be found in more than one embodiment, or may be found in all embodiments, or may be found in no embodiments. Although one or more features and/or elements may be described herein in the context of only a single embodiment, or in the context of more than one embodiment, or in the context of all embodiments, the features and/or elements may instead be provided separately or in any appropriate combination or not at all. Conversely, any features and/or elements described in the context of separate embodiments may alternatively be realized as existing together in the context of a single embodiment.
[0043] Any particular and all details set forth herein are used in the context of some embodiments and therefore should not necessarily be taken as limiting factors to the proposed disclosure. The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such process or method. Similarly, one or more devices or sub-systems or elements or structures or components proceeded by “comprises... a” does not, without more constraints, preclude the existence of other devices or other sub-systems or other elements or other structures or other components or additional devices or additional sub-systems or additional elements or additional structures or additional components.
[0044] Embodiments explained herein relate to a simple, compact, and efficient relates to a system and method for manufacturing of Inconel flanges. The Inconel is preferably an Inconel 718, however is not limited to Inconel 718 and can include Inconel Alloy 625 and Inconel Alloy 600.
[0045] According to an aspect, the disclosed system and method for manufacturing of Inconel flanges aims to provide a forging process of the Inconel 718 Flange to overcome the above-mentioned drawbacks of the conventional isothermal forging, hammer forging and press forging methods. Further, the present invention provides a forging process design to reduce the forces required to forge the Inconel 718 Flange. The present invention specifically focused on Inconel 718 flange forging as shown in FIG. 1. Its geometrical features like thin sections and side-by-side presence of deep cavity 101 and shallow cavity 102 increase the complexity of the part that creates difficulties while fill-up. Further, three parts are produced integrally as one part in one flow up to the rolling step and then split it into the three separate parts by machining followed by finisher operation. The forging process of manufacturing of Inconel 718 flange is shown in FIGs. 2B-2C and the following advantages for the same:
[0046] Increase productivity due to three parts produced integrally as one part, hence overall cycle time reduced. Use of slow strain rate equipment such as a hydraulic press or a screw press in combination with applying higher deformation (than conventional methods) per step helps in uniform deformation of the material throughout the part, and hence, produces more uniform microstructure in the part.
[0047] Less number of heats and booster heats are required when producing the part on the forging press. This further helps the uniformity of the microstructure. Improved material yield, because in invented method does not form flash throughout the process.
[0048] The Inconel 718 manufacturing process using conventional known hammer forging method specifically comprises the following broad steps as shown in FIG. 2A: Input Raw material – Billet heating - 1st Upset - Heating of 1st Upset - 2nd Upset - Heating of 2nd Upset - Buster – Heating of buster – Piercing of buster - Heating of pierced buster - Blocker - Heating of blocker – Finisher.
[0049] Input Raw Material: In conventional processes raw material is used as a forged, rolled or extruded billet. Material is Inconel 718 and preferably cylindrical in shape.
[0050] Billet Heating: The billet is heated to the required temperature in a furnace. Preferably, an electric furnace or gas-fired furnace is used for the billet heating. The temperature is maintained in the range between 1000° to 1025° C.
[0051] 1st Upset: In this process, the billet is deformed between the top and bottom dies on the hammer. It is ensured that the billets are kept on a flat die in the center vertical position and then gradually forged by number of blows on hammer forging.
[0052] Heating of 1st upset: The 1st upset after cooling to room temperature is then reheated in a furnace to produce a heated 1st upset preform. The parameters described in step 2 of Billet Heating are applicable here also.
[0053] 2nd Upset: In this process, the heated 1st upset is deformed between the top and bottom dies on hammer. The deformation in the 2nd upset preform forging step can be performed in multiple blows on hammer forging.
[0054] Heating of 2nd upset: The 2nd upset after cooling to room temperature is then reheated in a furnace to produce a heated 2nd upset preform. The parameters described in step 2 of Billet Heating are applicable here also.
[0055] Buster: The heated 2nd upset from the furnace is forged in a Buster die by positioning them centrally on the die impression. The bottom die is lubricated before giving the first blow. Material deformed in radial direction with the number of blows to get ready for blocker operation.
[0056] Heating of buster: The buster after cooling to room temperature is then reheated in a furnace to produce a heated buster preform. The parameters described in step 2 of Billet Heating are applicable here also.
[0057] Pierced buster: Piercing operation were carried out to remove the central portion of the buster and same can be used for the input for blocker operation.
[0058] Heating of pierced buster: The pierced buster after cooling to room temperature is then reheated in a furnace to produce a heated pierce buster preform. The parameters described in step 2 of Billet Heating are applicable here also.
[0059] Blocker: For the formation of blockers by forging, the heated busters from the furnace are centrally positioned on the blocker die impression. The bottom die was lubricated before first blow. Blocker preform shape which is used for the final finisher operation.
[0060] Heating of blocker: The blocker after cooling to room temperature is then reheated in a furnace to produce a heated blocker preform. The parameters described in step 2 of Billet Heating are applicable here also.
[0061] Finisher: The heated blocker from the furnace are centrally positioned on a finisher die impression. The bottom die was lubricated before first blow. Material is deformed with number of blows to form a final shape of the part.
[0062] In contrast to the conventional process, the Inconel 718 nickel-based alloy forging method as per the present invention specifically comprises the following broad steps as shown in FIGs. 2B and 2C.
[0063] Input Raw material - Billet heating - Upset - Heating of Upset - Doughnut 1 - Heating of Doughnut 1 - Doughnut 2 - Punching and piercing of Doughnut 2 - Heating of pierced doughnut - Ring rolling - Ring Splitting – Heating of ring - Finisher.
[0064] Input Raw Material: According to the invented process the manufacturing process starts with a forged, extruded or rolled billet as a raw material. The material is Inconel 718 and preferably cylindrical in shape.
[0065] Billet Heating: The billet is heated to the required temperature in a furnace. Preferably an electric furnace or gas fired furnace is used for the billet heating. The temperature is maintained in the range between 1000° to 1025° C.
[0066] Upset: In this process, the billet is deformed between the top and bottom dies at a predefined height and diameter with the help of the pot-type die. The deformation in the upset preform forging step can be performed in one stroke with 30 to 40% deformation and ram speed is between 20 to 30 mm/Sec. The die temperature is maintained in between 250-300 °C.
[0067] Heating of upset: The upset after cooling to room temperature is then reheated in a furnace to produce a heated upset preform. The parameters described in step 2 of Billet Heating are applicable here also.
[0068] Doughnut 1: the heated upset is subjected to doughnut forging to produce doughnut 1 as shown in Fig. 3. Two doughnut dies namely top and bottom dies are used for this operation. The impressions or die cavity on the top and bottom dies are such that when they come together for doughnut 1 forging the enclosed cavity has the shape required for production of doughnut 1. The die temperature is maintained in between 250-300 °C.
[0069] Heating of Doughnut 1: The doughnut 1 is then booster heated in a furnace to produce a heated doughnut 1 preform. The parameters described in step 2 of Billet Heating are applicable here also.
[0070] Doughnut 2: Innovative doughnut designed for top die 304 and Bottom dies 305 for doughnut operation, designed in such a way that material contact is avoided at the top and bottom surface. The die temperature is maintained in between 250-300 °C. The contact area of workpiece and top and bottom dies is minimum as compared with conventional design. The material deformed in a reverse extrusion manner which allows doughnut 306 formation (of ~165 kg) at a very low forging load of ~ 3500 T followed by piercing operation. The difference between conventional doughnut design and innovative design is shown in FIGs. 3A-3B.
[0071] Punching and piercing of Doughnut 2: after doughnut 2 operation, Punching is carried out followed by piercing operation on same press to remove the central portion of the doughnut 2 to form a pierced doughnut shape which is the input shape for the ring rolling operation.
[0072] Heating of Pierced doughnut: The pierced doughnut after cooling to room temperature is then reheated in a furnace to produce a heated pierced doughnut preform. The parameters described in step 2 of Billet Heating are applicable here also.
[0073] Ring Rolling: Ring rolling operations were carried out on a ring rolling machine with a pierced doughnut as an input to form the final dimensions of the ring. In this step material spread in radially with increase in diameter. This operation can also be performed in one step or multiple steps with booster heating between any two consecutive steps. After completion of this step, the ring is cooled down to room temperature. The king roll and mandrel temperature is maintained in between 250-300 °C. Three-in-one part is produced from upset to ring rolling operations.
[0074] Ring Splitting: After the ring rolling operation, the ring is split into three parts by machining operation.
[0075] Heating of ring: The split ring after cooling to room temperature is then reheated in a furnace to produce a heated ring preform. The parameters described in step 2 of Billet Heating are applicable here also.
[0076] Finisher: An innovative finisher top die 404 and bottom die 405 design was developed with optimized temperature, strain, and strain rate with the unrestricted material flow in outer diameter, inner diameter, and height 407 as shown in FIGs. 4A-4B.
[0077] This enables to reduce forging load drastically as compared with the conventional method. Details are illustrated in FIGs. 4A-4B. The die temperature is maintained in between 250-300 °C. The uniform microstructure observed without any shear bands and cracks as shown in FIG. 5. Maximum effective strain observed up to 2.5. Finisher die is designed in such a way that, no flash formation in horizontal as well as vertical directions. Hence force requirement is reduced drastically and parts can be produced on low capacity press.
[0078] Solution treatment: solution treatment temperature is carried out at a temperature range between 940°C to 970°C for 90 Min. followed by oil quenching. After that precipitation treatment is carried out in two steps in the first step temperature is a temperature range between 710°C to 730°C for 8 hrs. followed by furnace cool and in the second stage heating at a temperature range between 610°C to 630°C for 8 hrs. followed by air cool.
[0079] Testing and validation: Microstructural and mechanical testing were carried out and it achieves the all required specifications. The uniform microstructure is observed without. any shear bands, flow localization and cracks and the same was shown in FIG. 5.
[0080] Broad steps comparison of conventional Inconel 718 nickel-based alloy forging method (as shown in FIG. 2A) and the Inconel 718 nickel-based alloy forging method present invention (as shown in FIG. 2B-2C):

CONVENTIONAL METHOD PRESENT INVENTION
1st UPSET - Inconel 718 material is difficult to forge, hence the large number of blows required to achieve 30 to 40% deformation on the hammer in
the conventional method. UPSET – Whereas, deformation is done in one stroke only on press. The material deforms uniformly. 3 in 1 parts are produced from the upset-to-ring rolling
operation; hence, it improves productivity.
2nd UPSET - Inconel 718 material is difficult to forge, hence the large number of blows required and the
ovality observed in the upset. DOUGHNUT 1 - Deformation done in one stroke in the top and bottom impressions dies so that no ovality shape is observed.
BUSTER – Due to the number of blows required on the hammer, an eccentric shape was observed in the buster operation. Sometimes underfill is observed on the top, bottom, or one
side of the buster. DOUGHNUT 2 – Due to the innovative design of the doughnut dies, the material flow is uniform and no material defects have been observed.

PIERCED BUSTER – The overall yield of the material was reduced due to a large portion of the material waste
in the slug. PUNCHING & PIERCING –Only a thin section of the slug is pierced after the punching operation, so that improves the
overall material yield.
BLOCKER – Eccentricity is observed in blocker operations. uniform microstructure and dimensional
accuracy were not observed. RING ROLLING – Uniform grain flow was observed in the ring rolling operation, and no material defects were observed.
RING SPLITTING –3 in 1 parts are produced up to the ring rolling operation, so that the ring is split into three parts by the machining followed by the finisher
operation.
FINISHER - Due to the complex shape, uneven strain penetration and microstructure were observed throughout the part. The final microstructure and dimensions do not meet the required specifications, and forging defects were observed in the
conventional method. FINISHER - Uniform and easy material flow for large and complex geometry flanges. The final microstructure and dimensions meet the required specifications. Defect-free parts were produced in the present invention.

[0081] Referring to FIG.2D, the disclosed method (hereinafter referred to as “method 200”) for manufacturing an Inconel flange includes a step 202 of first forging a heated upset preform to form a first doughnut preform using a forging press and another step 204 of first heating the first doughnut preform to a second predefined temperature using a furnace to form a first heated first doughnut preform. A top die 304 and a bottom die 305 of the forging press at a first predefined temperature forges a profile over the heated upset preform during first forging. Additionally, the method 200 includes a step 206 of second forging the first heated first doughnut preform to form a second doughnut preform using the forging press punching and another step 208 of piercing the second doughnut preform for removing a central portion from the second doughnut preform to form a pierced second doughnut preform. A die profile of the top die 304 and bottom die 305 at the first predefined temperature prevents machined off material coming into contact between the top die 304 and the bottom die 305 such that the machined off material is deformed in a reverse extrusion manner, enabling the forging press to use low load for forming second forging operation on the first heated first doughnut preform.
[0082] Further, the method 200 includes a step 210 of second heating the pierced second doughnut preform 306 to the second predefined temperature using the furnace forms a second heated pierced doughnut preform. The method 200 includes a step 212 of ring rolling the second heated pierced doughnut preform to form a ring using a ring roller and mandrel. Another step of machining to split the ring into three parts, forming three split rings. A king roll and a mandrel of the ring roller are maintained at the first predefined temperature during ring rolling.
[0083] Furthermore, the method 200 includes a step 216 of third heating each of the three split rings to the second predefined temperature using the furnace forms a third heated split ring and another step 218 of finishing the third heated split ring using the forging press to achieve final dimensions of the flange having one or more thin sections, a deep cavity, and a shallow cavity. A top die 404 and a bottom die 405 of the forging press maintained at a first predefined temperature, allows material flow in one or more grooved portions in the inner and outer diameters between the top die 404 and the bottom die 405 and at least one height in the bottom die, forms the Inconel flange with a uniform microstructure having an effective strain up to 2.5 and near zero shear bands and cracks.
[0084] In an embodiment, the method 200 may include a pre-step of slicing a raw Inconel to obtain a cylindrical billet and another pre-step of heating the sliced cylindrical billet to the second predefined temperature using the furnace forms a heated cylindrical billet. In addition, the method 200 may include a step of deforming the heated cylindrical billet to form an upset preform using the top die 304 and the bottom die 305 at the first predefined temperature. The upset preform may be achieved in a single stroke of the forging machine. Further, the method may include a pre-step of reheating the upset preform to the second predefined temperature after being cooled to a third predefined temperature using the furnace forms the heated upset.
[0085] In an embodiment, the first predefined temperature can be selected between a temperature range between 250°C to 300°C and the second predefined temperature can be selected between a temperature range between 1000°C to 1025°C.
[0086] In an embodiment, the preformed Inconel flange can be cooled to the third predefined temperature before first heating, second heating, third heating, and finishing. The third predefined temperature can be selected from a temperature range between 20°C to 30°C.
[0087] In an embodiment, the method 200 may include a step of solution treating the finished flanges at a temperature range between 940°C to 970°C for 1.5 hours followed by oil quenching.
[0088] In an embodiment, the method 200 can include a step of first precipitation treating the solution-treated flanges at a temperature range between 710°C to 730°C for 8 hours followed by furnace cooling the first precipitation-treated flange.
[0089] In an embodiment, the method 200 can include a further step of solution-second precipitation treating, the first precipitation treated flanges at a temperature range between 610°C to 630°C for 8 hours followed by air cooling the second precipitation-treated flange.
[0090] Referring to FIGs. 6A-6B illustrates a table below shows a clear difference between the steps of the conventional forging method that are used in the present invention, those which are not used and those which are newly added/required for forging method as per the present invention.
[0091] Referring to FIG.7, the disclosed system 700 for manufacturing an Inconel flange includes a forging press 702 having a top die and a bottom die adapted to generate heat to a temperature range between 250°C to 300°C. The forging press 702 is configured to move towards and away from a raw Inconel flange. The Inconel flange is positioned between the top die and the bottom die such that a die profile of the top die and bottom die is forged on the raw Inconel flange. The finisher die profile provides one or more cavities in the inner and outer diameters between the top die and the bottom die and at least one groove in the bottom die for preventing removed material from the raw Inconel flange from coming into contact between the top die and the bottom die enabling the forging press to use low load during forging operation.
[0092] In addition, the system 700 includes a furnace 704 configured for heating the raw Inconel flange to a temperature range between 1000°C to 1025°C. The furnace 704 may be selected from an electric furnace and a gas furnace. Further, the system 700 includes a ring roller 706 includes a king roll and a mandrel adapted to generated heat at a temperature range between 250°C to 300°C. The ring roller 706 is configured to perform a rolling operation on the raw Inconel flange. The system 700 forms the Inconel flange with a uniform microstructure having an effective strain up to 2.5 and near zero shear bands and cracks.
[0093] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions, or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

ADVANTAGES OF THE PRESENT DISCLOSURE
[0094] The present disclosure is to provide a simple, compact, efficient, and cost-effective system and a method for manufacturing an Inconel flange.
[0095] The present disclosure is to develop innovative die designs for doughnut and finisher operations that enable the forging press to operate at lower loads and achieve precise dimensional tolerances.
[0096] The present disclosure is to validate the microstructural and mechanical properties of the finished Inconel flanges through rigorous testing, ensuring they meet all required specifications.
[0097] The present disclosure is to improve material yield by avoiding the formation of flash throughout the forging process.
[0098] The present disclosure is to minimize the number of heats and booster heats required during the forging process, thereby enhancing the uniformity of the microstructure and reducing material wastage.
,CLAIMS:1. A method for manufacturing an Inconel flange, the method (200) comprising steps of:
first forging (202), using a forging press a heated upset preform to form a first doughnut preform, wherein a top die (304) and a bottom die (305) of the forging press at a first predefined temperature forges a profile over the heated upset preform during first forging (202);
first heating (204), using a furnace the first doughnut preform to a second predefined temperature to form a first heated first doughnut preform;
second forging (206), using the forging press the first heated first doughnut preform to form a second doughnut preform, wherein a die profile of the top die (304) and the bottom die (305) at the first predefined temperature prevents machined off material coming into contact between the top die (304) and the bottom die (305) such that the machined off material is deformed in a reverse extrusion manner, enabling the forging press to use low load for forming second forging operation on the first heated first doughnut preform.
punching and piercing (208) the second doughnut preform for removing a central portion from the second doughnut preform to form a pierced second doughnut preform (306);
second heating (210), using the furnace the pierced second doughnut preform (306) to the second predefined temperature, forming a second heated pierced doughnut preform;
ring rolling (212), using a ring roller, the second heated pierced doughnut preform to form a ring. wherein a king roll and a mandrel of the ring roller are maintained at the first predefined temperature during ring rolling (212).
machining (214) to split the ring into three parts, forming three split rings;
third heating (216), using the furnace each of the three split rings to the second predefined temperature forming a third heated split ring; and
finishing (218), using the forging press the third heated split ring to achieve final dimensions of the flange having one or more thin sections, a deep cavity (101) and a shallow cavity (102), wherein a top die (404) and a bottom die (405) of the forging press maintained at a first predefined temperature, allows unrestricted material flow in one or more grooved portions in the inner and outer diameters between the top die (404) and the bottom die (405) and at least one height (407) in the bottom die (405), forms the Inconel flange with a uniform microstructure having an effective strain up to 2.5 and near zero shear bands and cracks.
2. The method (200) as claimed in claim 1, wherein the method (200) comprises pre-steps of:
slicing, a raw Inconel to obtain a cylindrical billet;
heating, using the furnace the sliced cylindrical billet to the second predefined temperature, forming a heated cylindrical billet;
deforming, using the top die (304) and the bottom die (305) at the first predefined temperature the heated cylindrical billet to form an upset preform, wherein the upset preform is achieved in a single stroke of the forging machine; and
reheating, using the furnace the upset preform to the second predefined temperature after being cooled to a third predefined temperature, forming the heated upset.
3. The method (200) as claimed in claim 1, wherein the first predefined temperature is selected between a temperature range between 250°C to 300°C.
4. The method (200) as claimed in claim 1, wherein the second predefined temperature is selected between a temperature range between 1000°C to 1025°C.
5. The method (200) as claimed in claim 1, wherein the preformed Inconel flange is cooled to the third predefined temperature before first heating, second heating, third heating, and finishing, wherein the third predefined temperature is selected from a temperature range between 20°C to 30°C.
6. The method (200) as claimed in claim 1, wherein the method (200) comprises a step of solution treating the finished flanges at a temperature range between 940°C to 970°C for 1.5 hours followed by oil quenching.
7. The method (200) as claimed in claim 6, wherein the method (200) comprises a step of first precipitation treating, the solution-treated flanges at a temperature range between 710°C to 730°C for 8 hours followed by furnace cooling the first precipitation-treated flange.
8. The method (200) as claimed in claim 8, wherein the method (200) comprises a further step of solution-second precipitation treating, the first precipitation treated flanges at a temperature range between 610°C to 630°C for 8 hours followed by air cooling the second precipitation-treated flange.
9. A system (700) for manufacturing an Inconel flange, the system (700) comprising:
a forging press (702) comprises a top die and a bottom die adapted to generate heat to a temperature range between 250°C to 300°C and configured to move towards and away from a raw Inconel flange that is positioned between the top die and the bottom die such that a finisher die profile of the top die and bottom die is forged on the raw Inconel flange, wherein the finisher die profile provides one or more cavities in the inner and outer diameters between the top die and the bottom die and at least one groove in the bottom die for preventing removed material from the raw Inconel flange from coming into contact between the top die and the bottom die enabling the forging press to use low load during forging operation;
a furnace (704) configured for heating the raw Inconel flange to a temperature range between 1000°C to 1025°C, wherein the furnace (704) is selected from an electric furnace and a gas furnace; and
a ring roller (706) comprises a king roll and a mandrel adapted to generated heat at a temperature range between 250°C to 300°C and configured to perform a rolling operation on the raw Inconel flange,
wherein the system (700) forms the Inconel flange with a uniform microstructure having an effective strain up to 2.5 and near zero shear bands and cracks.