Forming method for large end-face flanges

Abstract

This invention discloses a method for forming large end-face flange forgings. The method includes: heating a steel ingot to 1220±20℃ in a heating furnace and holding it at that temperature for a first preset time before removing it from the furnace; upsetting the steel ingot to obtain a cylindrical billet; rolling and dividing the cylindrical billet; heating the divided billet to 1220±20℃ in a heating furnace and holding it at that temperature for a second preset time before removing it from the furnace; with the flange outer end face of the billet facing upwards, repeatedly hammering the outer end face of the flange circumferentially using a press hammer at a position 90-110mm away from the outer side of the flange; rolling the hammered billet into a flange; placing the billet on a forging platform for shaft and step forming; and rolling and flattening the formed billet to obtain the forging. This method eliminates surface unevenness and inner edge collapse on the flange end face, and avoids defects such as pits. The flange portion and shaft portion have good perpendicularity, small deformation, and short processing time.

Description

Technical Field

[0001] This invention relates to the field of forging technology, and in particular to a method for forming large end-face flange forgings. Background Technology

[0002] In the manufacturing of existing large end-face flange forgings such as fan shafts and side shafts, the flange forgings are fed into a heating furnace for heating after being divided into materials. After heating, the forgings are put into a special tooling to widen the flange, and then the shaft body and steps are formed. After the shaft body and steps are formed, the flange is rolled and leveled.

[0003] However, due to the large diameter and thin thickness of the flange end face of large-face flange forgings, the large difference between the diameter of the blank and the shaft diameter during blank separation can easily lead to defects such as "inner collapse" and unevenness in the flange portion of the blank after separation. Furthermore, existing manufacturing methods are prone to producing pits on the flange end face due to oxide scale pressure when widening the flange. Summary of the Invention

[0004] To address some or all of the technical problems existing in the prior art, the present invention provides a method for forming large end-face flange forgings.

[0005] The technical solution of the present invention is as follows:

[0006] A method for forming large end-face flange forgings is provided, the method comprising the following steps:

[0007] The steel ingots are sent to a heating furnace and heated to 1220±20℃, and then kept at that temperature for the first preset time before being taken out of the furnace;

[0008] The steel ingot is upsetting to obtain a cylindrical billet;

[0009] The cylindrical blanks are rolled into rounds and divided into smaller portions.

[0010] The billets after being divided are sent to a heating furnace and heated to 1220±20℃, and then kept at that temperature for a second preset time before being taken out of the furnace;

[0011] With the outer end face of the flange facing upwards, use the press hammer to repeatedly hammer along the circumference of the outer end face of the flange at a position 90-110mm away from the outer side of the flange.

[0012] Roll the hammered billet into a flange;

[0013] The blank is placed on a forging platform for shaft and step forming;

[0014] The formed blank is rolled and leveled to obtain a forging.

[0015] Optionally, the diameter of the blank after splitting is 90-110 mm smaller than the diameter of the blank after upsetting.

[0016] Optionally, the first preset time is calculated as (K1×D1) / 100, in hours, K1 is 1.5 to 2.0, D1 = (D+d) / 2, where D is the diameter of the large end of the steel ingot and d is the diameter of the small end of the steel ingot, both in mm.

[0017] Optionally, the second preset time is calculated according to (K2×D2) / 100, in hours, where K2 is 1.2 to 1.5 and D2 is the diameter of the billet shaft.

[0018] Optionally, at a position 90-110mm away from the outer side of the flange, the flange is hammered three times using a press hammer, with the three hammering positions spaced 120° apart.

[0019] Optionally, the method further includes:

[0020] After the flange is rolled and leveled, the forging is placed on the press platform, and the shaft of the forging is hammered by the press hammer to straighten the shaft.

[0021] The main advantages of the technical solution of this invention are as follows:

[0022] The large end-face flange forging method of the present invention can eliminate the problems of uneven surface and inner collapse edge of flange end face, and there are no defects such as pits. The surface of flange end face has good flatness. The flange part of the forging has good perpendicularity to the shaft part, which can meet the actual requirements. The operation is simple, the amount of processing deformation is small, the required forming time is short, and the forging allowance of flange part can be effectively reduced. Attached Figure Description

[0023] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and constitute a part of this invention, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0024] Figure 1 This is a flowchart of a method for forming large end-face flange forgings according to an embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the structure of a large end-face flange forging prepared according to an embodiment of the present invention;

[0026] Figure 3 This is a schematic diagram of the flange end face hammering operation in a method for forming large end face flange forgings according to an embodiment of the present invention;

[0027] Figure 4This is a schematic diagram of the hammering operation of the clamp handle in a method for forming large end-face flange forgings according to an embodiment of the present invention. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0029] The technical solutions provided by the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0030] See Figure 1-2 An embodiment of the present invention provides a method for forming large end-face flange forgings, the method comprising the following steps:

[0031] The steel ingot is sent to a heating furnace and heated to 1220±20℃. After holding at that temperature for a certain period of time, it is taken out of the furnace. The holding time is calculated according to (K1×D1) / 100, in hours. K1 is 1.5~2.0, D1=(D+d) / 2, where D is the diameter of the large end of the steel ingot and d is the diameter of the small end of the steel ingot, both in mm.

[0032] The steel ingot is upsetting to obtain a cylindrical billet;

[0033] The cylindrical blanks are rolled into rounds and divided into smaller portions.

[0034] The billets after being divided are sent to a heating furnace and heated to 1220±20℃. After being held at that temperature for a certain period of time, they are taken out of the furnace. The holding time is calculated according to (K2×D2) / 100, in hours. K2 is 1.2~1.5, and D2 is the diameter of the billet shaft.

[0035] With the outer end face of the flange facing upwards, use the hammer head of the free forging press to repeatedly hammer along the circumference of the outer end face of the flange at a position 90-110mm away from the outer side of the flange.

[0036] Roll the hammered billet into a flange;

[0037] The blank is placed on a forging platform for shaft and step forming;

[0038] The formed blank is rolled and leveled to obtain a forging.

[0039] Optionally, in one embodiment of the present invention, the diameter of the blank after material division is controlled to be 90-110 mm smaller than the diameter of the blank after upsetting.

[0040] This facilitates subsequent flange forming, as well as bearing and step forming.

[0041] Furthermore, in one embodiment of the present invention, at a position 90-110mm away from the outer surface of the flange, the free end press hammer is used to uniformly hammer multiple times along the circumference of the outer surface of the flange.

[0042] See Figure 3 Optionally, in one embodiment of the present invention, the hammer head of a free forging press is used to uniformly strike the flange three times along the circumference of the outer end face of the flange, and the three strikes are spaced 120° apart.

[0043] This design allows the outer end of the flange to curve upwards, eliminating the inner collapse of the flange, and also increases the diameter of the arc portion connecting the inner side of the flange to the shaft, facilitating subsequent forming and processing of the flange and bearing. At the same time, hammering the flange end face can remove the oxide scale adhering to the flange end face, further improving the surface flatness of the formed flange end face.

[0044] Further, see Figure 4 In one embodiment of the present invention, the method may further include:

[0045] After the flange is rolled and leveled, the forging is placed on the platform of the free forging press, and the clamp part of the shaft of the forging is hammered by the hammer of the free forging press.

[0046] By hammering the clamp portion of the shaft, the perpendicularity between the flange portion of the forging and the shaft portion can be further improved.

[0047] To make the above technical solutions of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0048] Example 1

[0049] In Embodiment 1 of the present invention, before the steel ingot is heated, the raw materials for preparing the steel ingot are determined according to the intended use of the large end-face flange forging. Based on the determined raw materials, traditional preparation methods can be used, such as "alkaline electric furnace smelting + ladle refining + vacuum degassing + vacuum carbon deoxidation method" to prepare the corresponding steel ingot.

[0050] The method for forming large end-face flange forgings according to Embodiment 1 of the present invention includes the following steps:

[0051] The steel ingot is sent to the heating furnace and heated to 1220℃. After holding at that temperature for a certain period of time, it is taken out of the furnace. The holding time is calculated according to (K1×D1) / 100, in hours. K1 is taken as 1.8, D1=(D+d) / 2, where D is the diameter of the large end of the steel ingot and d is the diameter of the small end of the steel ingot, both in mm.

[0052] The steel ingot is upsetting to obtain a cylindrical billet;

[0053] The cylindrical blank is rolled and divided, and the diameter of the divided blank is 100mm smaller than the diameter of the upsetting blank.

[0054] The billet after being divided is sent to the heating furnace and heated to 1220℃. After being held at that temperature for a certain period of time, it is taken out of the furnace. The holding time is calculated according to (K2×D2) / 100, in hours. K2 is 1.4 and D2 is the diameter of the billet shaft.

[0055] With the outer end face of the flange of the blank facing upward, use the hammer of the free forging press to hammer three times along the circumference of the outer end face of the flange at a distance of 100mm from the outer side of the flange, and the three hammering positions are 120° apart.

[0056] Roll the hammered billet into a flange;

[0057] The blank is placed on a forging platform for shaft and step forming;

[0058] The formed blank is rolled and leveled to obtain a forging.

[0059] The forging is placed on the platform of the free forging press, and the clamp part of the shaft of the forging is hammered by the hammer of the free forging press.

[0060] The flange end face of the forging prepared in Example 1 of this invention has a smooth surface without defects such as pits, and the perpendicularity of the flange part and the bearing part meets the accuracy requirements.

[0061] Compared with the prior art, the method for forming large end-face flange forgings provided in an embodiment of the present invention has the following advantages:

[0062] The large end-face flange forging method provided in one embodiment of the present invention can eliminate the problems of uneven surface and inner collapse edge of flange end face, and there are no defects such as pits. The surface of flange end face has good flatness.

[0063] The flange portion of the forging obtained by the large end-face flange forging method provided in one embodiment of the present invention has good perpendicularity to the shaft portion, which can meet the actual requirements.

[0064] The method for forming large end-face flange forgings provided in one embodiment of the present invention is simple to operate, has a small amount of processing deformation, and requires a short forming time, which can effectively reduce the forging allowance of the flange part.

[0065] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Additionally, the terms "front," "back," "left," "right," "upper," and "lower" in this document refer to the placement shown in the accompanying drawings.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for forming large end-face flange forgings, characterized in that, Includes the following steps: The steel ingots are sent to a heating furnace and heated to 1220±20℃, and then kept at that temperature for the first preset time before being taken out of the furnace; The steel ingot is upsetting to obtain a cylindrical billet; The cylindrical blanks are rolled into rounds and divided into smaller portions. The billets after being divided are sent to a heating furnace and heated to 1220±20℃, and then kept at that temperature for a second preset time before being taken out of the furnace; With the outer end face of the flange facing upwards, at a position 90-110mm away from the outer side of the flange, use the press hammer to strike the flange end face three times along the circumference of the outer end face, with the three strikes spaced 120° apart. Roll the hammered billet into a flange; The blank is placed on a forging platform for shaft and step forming; The formed blank is rolled and leveled to obtain a forging. After the flange is rolled and leveled, the forging is placed on the press platform, and the shaft of the forging is hammered by the press hammer to straighten the shaft.

2. The method for forming large end-face flange forgings according to claim 1, characterized in that, The diameter of the blank after separation is 90-110 mm smaller than the diameter of the blank after upsetting.

3. The method for forming large end-face flange forgings according to claim 1, characterized in that, The first preset time is calculated as (K1×D1) / 100, in hours. K1 is 1.5 to 2.0, D1 = (D+d) / 2, where D is the diameter of the large end of the steel ingot and d is the diameter of the small end of the steel ingot, both in mm.

4. The method for forming large end-face flange forgings according to claim 1, characterized in that, The second preset time is calculated as (K2×D2) / 100, in hours, where K2 is 1.2 to 1.5 and D2 is the diameter of the billet shaft.

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