A process for rolling rings of nickel-base alloys

Abstract

The application discloses a process for rolling a ring of a nickel-based alloy, and the technical scheme comprises the following steps: S1, blank upsetting and punching: preparing a blank, upsetting the blank, and then punching the blank; S2, blank hole expanding: expanding the inner hole of the blank by using a mandrel; S3, blank special-shaped mandrel expanding: preparing a special-shaped mandrel, preliminarily machining a boss in the inner hole of the blank by using the special-shaped mandrel, and obtaining a special-shaped blank; and S4, blank special-shaped ring rolling: preparing a ring rolling device, extruding the special-shaped blank by using the ring rolling device, and then forming the boss in the inner hole of the special-shaped blank, wherein the process has the advantages that two different rolling strategies are adopted, the inner hole of the ring blank is effectively formed, the boss is machined on the outer side of the ring blank, and the defects of the ring blank are filled.

Description

Technical Field

[0001] This invention relates to the field of nickel-based alloy ring rolling technology, and more particularly to a process for nickel-based alloy ring rolling. Background Technology

[0002] Nickel-based alloys are alloys with Ni as the base material and other alloying elements. They possess excellent strength and toughness under high-temperature conditions (600–1000℃) and are resistant to oxidation and corrosion, making them a class of alloys with outstanding comprehensive properties. Due to their excellent properties, nickel-based alloys are used to manufacture various components for petroleum equipment, chemical equipment, and power equipment.

[0003] Currently, there is a need to manufacture a high-temperature alloy forging, the structure of which is shown below. Figure 1 The forging has a small boss in its inner hole. If a rectangular ring billet is used for conventional rolling, the boss in the inner hole of the forging cannot be formed. Figure 2 As shown, a deep depression is formed at the outer edge of the forging, which makes it impossible for the size and shape of the forging to meet the processing requirements. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a process for rolling nickel-based alloy rings. Its advantage lies in the two different rolling strategies, which effectively form the inner hole of the ring blank and process the boss on the outer side of the ring blank, which helps to fill the defects of the ring blank.

[0005] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0006] A process for rolling nickel-based alloy rings includes the following steps:

[0007] Step S1, billet upsetting and punching:

[0008] Prepare the blank, upset and draw the blank, and then punch holes in the blank;

[0009] Step S2: Expanding the hole in the billet;

[0010] Use a frame to enlarge the inner hole of the blank;

[0011] Step S3, irregular shape expansion of billet:

[0012] A special-shaped mold is prepared, and a boss is initially machined in the inner hole of the blank using the special-shaped mold to obtain a special-shaped blank. The special-shaped mold includes a hole-expanding mandrel, a lower mold and an upper mold. The lower mold is sleeved in the hole-expanding mandrel. The outer side of the lower mold is provided with a groove for forming the boss. The upper mold and the lower mold are spliced ​​together. After the upper mold and the lower mold are assembled, an inner cavity for accommodating the blank is formed between the upper mold and the lower mold.

[0013] Step S4, irregularly shaped ring rolling of billet:

[0014] A ring-rolling device is prepared to extrude irregularly shaped billets to form bosses in the inner holes of the billets. The ring-rolling device includes a main roller, a combined core roller, an upper conical roller, and a lower conical roller. A space is left between the main roller and the combined core roller to accommodate the irregularly shaped billet. The main roller contacts the outer wall of the irregularly shaped billet, and the combined core roller contacts the inner wall of the irregularly shaped billet. The upper conical roller and the lower conical roller are arranged on horizontal planes at different heights. The upper conical roller contacts the top surface of the irregularly shaped billet, and the lower conical roller contacts the bottom surface of the irregularly shaped billet.

[0015] Furthermore, in step S1, the forging ratio of upsetting and drawing of the cylindrical blank is 7, and the punching size of the cylindrical blank is Φ300mm.

[0016] Furthermore, in step S2, the dimensions of the blank after the hole is enlarged are Φ1525×Φ1000×727.5mm.

[0017] Furthermore, in step S3, the two ends of the lower mold are provided with inclined surface one, and the side wall of the cavity of the upper mold is provided with inclined surface two. The inclined surface two and inclined surface one have the same inclination angle. When the upper mold and the lower mold are combined, inclined surface one and inclined surface two abut against each other.

[0018] Furthermore, in step S3, a second groove is formed on the bottom surface of the cavity of the upper mold.

[0019] Furthermore, in step S3, a boss is provided on the outer wall of the irregular blank, and the boss is located in the middle of the outer wall of the irregular blank.

[0020] Furthermore, in step S3, a protrusion is provided on the inner wall of the irregular blank, and the protrusion divides the inner wall of the irregular blank into a hole wall one and a hole wall two.

[0021] Furthermore, the combined core roller is fitted with a shaped core roller sleeve for forming the inner wall of the shaped blank.

[0022] Furthermore, the irregularly shaped core roller sleeve has grooves for forming protrusions.

[0023] Furthermore, the width of the first hole wall is smaller than the width of the second hole wall.

[0024] In summary, the present invention has the following beneficial effects:

[0025] 1. The ring billet was pre-divided and two different rolling strategies were adopted. First, the billet was pre-rolled by shaped expansion to fully fill the inner hole shape. The outer edge was machined on the outer edge of the billet. The purpose of this process is twofold: first, to supplement the missing material at the outer circle in the first stage of rolling; and second, to effectively reduce the axial reduction, allowing the material to flow to the designated position. The ring rolling process is also more stable and the ellipticity of the ring is smaller.

[0026] 2. During the irregular forging process, the protrusion in the inner hole of the billet is formed through the groove one of the upper die; during the irregular forging process, the boss in the outer edge of the billet is formed through the groove two of the lower die; then, in the irregular ring rolling process, radial feed is first performed, and the irregular billet is radially rolled by the main roll and the combined core roll, so that the step of the irregular billet will gradually decrease until it is zero. Then, the upper tapered roll feeds downward to perform combined radial and axial rolling. Due to the different degrees of material movement from the inner hole to the outer circle during the rolling process, after the boss on the outer circle of the ring becomes zero, a pit will gradually be generated. At this time, axial feed begins, and the material is filled to the outer circle by pressing down in the height direction, so as to avoid pits on the outer edge of the billet and solve the defects encountered in traditional forging.

[0027] 3. During the mold closing process of the upper and lower molds, the inclined surface one of the upper mold and the inclined surface two of the lower mold cooperate with each other to restrict the engagement position of the upper and lower molds and prevent misalignment. Attached Figure Description

[0028] Figure 1 This is a partial structural diagram of the forging.

[0029] Figure 2 This is a schematic diagram of the structure of a conventionally rolled forging.

[0030] Figure 3 This is a schematic diagram of the irregularly shaped horse frame.

[0031] Figure 4 This is a schematic diagram of the structure of the billet undergoing irregular shape expansion.

[0032] Figure 5 This is a schematic diagram of the ring rolling device.

[0033] Figure 6 This is a structural schematic diagram of an irregularly shaped billet.

[0034] In the diagram, 1. Irregularly shaped frame; 11. Expanding mandrel; 12. Lower die; 121. Inclined surface one; 122. Groove one; 13. Upper die; 131. Inclined surface two; 132. Groove two; 2. Ring rolling device; 21. Main roller; 22. Combined mandrel; 23. Irregularly shaped mandrel sleeve; 24. Upper conical roller; 25. Lower conical roller; 3. Irregularly shaped billet; 31. Boss; 32. Protrusion; 33. Hole wall one; 34. Hole wall two. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the device proposed by this invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of this invention will become clearer from the following description. It should be noted that the drawings are in a very simplified form and use non-precise proportions, only for the purpose of conveniently and clearly illustrating the embodiments of this invention. Please refer to the accompanying drawings to make the objectives, features, and advantages of this invention more apparent and understandable. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of this invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationships, or adjustments to the size, without affecting the effects and objectives achieved by this invention, should still fall within the scope of the technical content disclosed in this invention.

[0036] Example:

[0037] A process for rolling nickel-based alloy rings includes the following steps:

[0038] Step S1, billet upsetting and punching:

[0039] Prepare the billet, upsetting it according to the forging ratio of 7, and then punching a Φ300mm hole at the center axis of the billet.

[0040] Step S2: Expanding the hole in the billet;

[0041] The inner hole of the billet is enlarged using a frame, and the dimensions of the billet after enlargement are Φ1525×Φ1000×727.5mm.

[0042] Step S3, irregular shape expansion of billet:

[0043] like Figure 3 As shown, a special-shaped mold frame 1 is prepared, which includes a reaming mandrel 11, a lower mold 12, and an upper mold 13. The lower mold 12 is fitted into the reaming mandrel 11, and the lower mold 12 and the reaming mandrel 11 are welded and fixed. The outer surface of the lower mold 12 is provided with a groove 122 for forming a boss 31, and the two end faces of the upper mold 13 are provided with inclined surfaces 121. The size of the upper mold 13 is larger than that of the lower mold 12. A cavity is opened in the upper mold 13, and the shape of the cavity of the upper mold 13 matches the shape of the lower mold 12. A second groove 132 is opened on the bottom surface of the cavity of the upper mold 13, and the side wall of the cavity of the upper mold 13 is set as an inclined surface 131. The upper mold 13 and the lower mold 12 are spliced ​​together, and after the upper mold 13 and the lower mold 12 are assembled, an inner cavity for accommodating the blank is formed between the upper mold 13 and the lower mold 12.

[0044] Specific work process: such as Figure 4As shown, the blank is placed in the cavity of the lower mold 12, then the upper mold 13 moves to the lower mold 12, and then the inclined surface 121 and the inclined surface 131 come into contact, thereby achieving precise positioning and mold closing of the upper mold 13 and the lower mold 12, without misalignment. During the molding process, the blank material is filled into the grooves 122 and 132 to form the irregularly shaped blank 3. Figure 6 As shown, a boss 31 is provided on the outer wall of the irregular blank 3. The boss 31 is located in the middle of the outer wall of the irregular blank 3 and is formed in the blank material filling groove 132. A protrusion 32 is provided on the inner wall of the irregular blank 3. The protrusion 32 is formed in the blank material filling groove 122 and divides the inner wall of the irregular blank 3 into a hole wall 33 and a hole wall 34.

[0045] Step S4, irregularly shaped ring rolling of billet:

[0046] Prepare a ring rolling device 2, and use the ring rolling device 2 to extrude the irregular blank 3 to form the boss 31 in the inner hole of the irregular blank 3.

[0047] Specifically, such as Figure 5 As shown, the ring rolling device 2 includes a main roller 21, a combined core roller 22, an upper conical roller 24, and a lower conical roller 25. A space is provided between the main roller 21 and the combined core roller 22 to accommodate the shaped blank 3. The main roller 21 contacts the outer wall of the shaped blank 3, and the combined core roller 22 contacts the inner wall of the shaped blank 3. A shaped core roller sleeve 23 is fitted onto the combined core roller 22, and a groove is formed on the shaped core roller sleeve 23 for forming the protrusion 32 of the shaped blank 3. The upper conical roller 24 and the lower conical roller 25 are arranged on horizontal planes at different heights. The upper conical roller 24 contacts the top surface of the shaped blank 3, and the lower conical roller 25 contacts the bottom surface of the shaped blank 3.

[0048] Specific work process:

[0049] like Figure 5 As shown, at the start of ring rolling, the combined core roll 22 performs radial feeding, while the upper conical roll 24 does not feed, and the shaped billet 3 is radially rolled. During this process, the step of the shaped billet 3 gradually decreases until it becomes zero. Then, the upper conical roll 24 feeds downward, performing combined radial and axial rolling. Due to the different degrees of material movement from the inner hole to the outer circle during rolling, after the boss 31 becomes zero, a pit will gradually be generated. At this time, axial feeding begins, and the material is filled to the outer edge of the billet by downward pressure in the height direction, finally completing the rolling of the product.

[0050] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0051] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A process for rolling rings of nickel-based alloys, characterized in that, Includes the following steps: Step S1, billet upsetting and punching: Prepare the blank, upset and draw the blank, and then punch holes in the blank; Step S2: Expanding the hole in the billet; Use a frame to enlarge the inner hole of the blank; Step S3, irregular shape expansion of billet: A special-shaped die frame is prepared. The protrusions are initially machined in the inner hole of the blank using the special-shaped die frame to obtain the special-shaped blank. The special-shaped die frame includes a hole-expanding mandrel, a lower die, and an upper die. The lower die is sleeved in the hole-expanding mandrel. The outer side of the lower die is provided with a groove for forming the protrusions. The upper die and the lower die are spliced ​​together. After the upper die and the lower die are assembled, they form an inner cavity to accommodate the blank. Step S4, irregularly shaped ring rolling of billet: A ring-rolling device is prepared to extrude irregularly shaped billets to form protrusions in the inner holes of the billets. The ring-rolling device includes a main roller, a combined core roller, an upper conical roller, and a lower conical roller. A space is left between the main roller and the combined core roller to accommodate the irregularly shaped billet. The main roller contacts the outer wall of the irregularly shaped billet, and the combined core roller contacts the inner wall of the irregularly shaped billet. The upper conical roller and the lower conical roller are arranged on horizontal planes at different heights. The upper conical roller contacts the top surface of the irregularly shaped billet, and the lower conical roller contacts the bottom surface of the irregularly shaped billet. In step S1, the forging ratio of upsetting and drawing of the cylindrical blank is 7, and the punching size of the cylindrical blank is Φ300mm; In step S3, the two ends of the lower mold are provided with inclined surfaces one, and the side wall of the cavity of the upper mold is provided with inclined surfaces two. The inclined surfaces two and one are inclined at the same angle. When the upper mold and the lower mold are combined, the inclined surfaces one and two abut against each other. The bottom surface of the cavity of the upper mold is provided with a groove two. The outer wall of the irregular blank is provided with a boss, which is located in the middle of the outer wall of the irregular blank. The inner wall of the irregular blank is provided with a protrusion, which divides the inner wall of the irregular blank into a hole wall one and a hole wall two. The combined core roller is fitted with an irregular core roller sleeve for forming the inner wall of the irregular blank. The irregular core roller sleeve is provided with a groove for forming the protrusion.

2. A process for rolling rings of nickel-based alloys as claimed in claim 1, wherein: In step S2, the dimensions of the blank after the hole is enlarged are Φ1525×Φ1000×727.5mm.

3. A process for rolling rings of nickel-based alloys as claimed in claim 1, wherein: The width of the first hole wall is smaller than the width of the second hole wall.

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