Elliptical head forging and quenching process

Abstract

The invention discloses an elliptical head forging and quenching process which specifically comprises the following steps: S1, ingot material treatment, S2, forging treatment: transferring the ingot material in the step S1 into an electric arc furnace for forging at the forging temperature of 900-1300 DEG C, forging the ingot material into an elliptical head, and taking out the elliptical head; and S4, annealing treatment is conducted, specifically, the quenched ellipsoidal head is subjected to annealing treatment, heat preservation is conducted for 10-20 min, then the ellipsoidal head is naturally cooled to the room temperature, then the annealed ellipsoidal head is clamped on a machine tool to be subjected to machining treatment, and therefore the ellipsoidal head is manufactured. According to the forging and quenching process for the elliptical head, good quenching and cooling control can be carried out by adopting a multi-nozzle spraying and cooling mode, and the purpose of greatly improving the forging and quenching efficiency of the elliptical head by simplifying the specific forging and quenching treatment process is well achieved, so that the forging and quenching treatment of the elliptical head is greatly facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical processing, in particular to an elliptical head forging and quenching process. Background Art

[0002] An elliptical head, also known as an elliptical head or an elliptical head, is composed of a rotating ellipsoidal surface and a cylindrical straight section. Its functions are: 1. When a pipe ends and is not to be extended, the head is welded to the pipe and used as an end. 2. It is used in pressure vessels, with a head on each side and a straight pipe section in the middle, serving as the pressure vessel's tank. An elliptical head with a ratio of the major to minor axis of the rotating ellipsoidal generatrix of 2.0 is conventionally referred to as a standard elliptical head. The mechanical properties of an elliptical head are second only to those of a hemispherical head, but superior to those of a dished head. Because the depth of an elliptical head lies between that of a hemispherical head and a dished head, the requirements for stamping equipment and molds, as well as the manufacturing difficulty, are also intermediate between the two, making it easier than a hemispherical head but more difficult than a dished head. In recent years, the adoption of spinning manufacturing processes has facilitated the manufacture of large-diameter elliptical heads. Elliptical heads are widely used in medium and low pressure vessels due to their good comprehensive performance. Before finishing the metal workpiece, it is necessary to perform heat treatment such as quenching on the metal workpiece. Quenching is a heat treatment process in which the product is first heated to a certain temperature, preheated for a period of time, and then heated to above the critical temperature, kept warm for a period of time, so that the product is fully or partially austenitized, and then rapidly cooled to below Ms (or isothermal near Ms) at a cooling rate greater than the critical cooling rate for martensite (or bainite) transformation.

[0003] The existing elliptical head forging quenching process is complicated and cumbersome, and the quenching cooling effect is poor. It cannot achieve the purpose of greatly improving the elliptical head forging quenching efficiency by adopting a multi-nozzle spray cooling method, and cannot achieve the purpose of greatly improving the elliptical head forging quenching efficiency by simplifying the specific forging quenching process, thereby bringing great inconvenience to the elliptical head forging quenching treatment. Summary of the Invention

[0004] (1) Technical problems solved

[0005] In response to the shortcomings of the existing technology, the present invention provides an elliptical head forging and quenching process, which solves the problems that the existing elliptical head forging and quenching process is complicated and cumbersome, and the quenching cooling effect is poor. It cannot achieve the purpose of greatly improving the forging and quenching efficiency of the elliptical head by simplifying the specific forging and quenching treatment process.

[0006] (2) Technical solution

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: an elliptical head forging and quenching process, specifically comprising the following steps:

[0008] S1. Ingot processing: Take the required raw steel ingot and use processing equipment to turn the edges and rust on its surface to make ingot;

[0009] S2, forging treatment: the ingot in step S1 is transferred to an electric arc furnace for forging at a forging temperature of 900-1300°C, and is forged into an elliptical head and taken out;

[0010] S3, quenching treatment: first arrange the exhaust pipe in the elliptical head formed in step S2, and then quench the head, first raise the temperature from room temperature to 600-800℃, keep it warm for 5-20 minutes, then raise it from room temperature to 900-1300℃, keep it warm for 10-20 minutes. After keeping warm, open the door of the heat treatment furnace, use a lifting device to lift the elliptical head from the heat treatment furnace to the top of the quenching equipment, adjust the position of the driving device so that the elliptical head is directly above the quenching cooling device, lower the driving device, and place the elliptical head into the quenching cooling device. During this process, the gas in the inner cavity of the head is discharged through the exhaust pipe, and the high-speed water flow sprayed from the nozzle of the internal spray device quickly cools the inner surface of the head;

[0011] S4. Annealing treatment: annealing the quenched elliptical head, keeping it warm for 10-20 minutes and then naturally cooling it to room temperature. Then, clamping the annealed elliptical head on a machine tool for machining, thereby obtaining an elliptical head.

[0012] Preferably, the processing equipment in step S1 includes a CNC lathe, a CNC milling machine and a CNC grinder.

[0013] Preferably, the exhaust pipe is arranged inside the elliptical head in step S3 by welding the exhaust pipe inside the head, and the air in the inner cavity of the head and the water vapor generated during quenching are discharged from the exhaust pipe. A steel pipe is used as the exhaust pipe, and the exhaust pipe part outside the head is fixed to the outer surface of the head with reinforcing ribs.

[0014] Preferably, the heating rate from room temperature to 600-800° C. in step S3 is 5-15° C. / min.

[0015] Preferably, the furnace temperature of the annealing treatment in step S3 is 700-800° C., and the holding time is 10-20 hours.

[0016] Preferably, during the quenching heat treatment in step S3, the furnace temperature is ≤200°C, the heating rate is ≤100°C / h, and when the quenching holding time is approaching, the high-pressure water pump connected to the main pipeline of the internal spray device is turned on to stir the water in the quenching water tank.

[0017] Preferably, the steel ingot forging process in step S2 is specifically as follows: placing the steel ingot into the groove on the die, then aligning the center line of the narrow anvil with the center line of the blank and driving the narrow anvil to press down. After each pressing is completed, the die is driven to drive the blank to rotate a certain angle and then the narrow anvil is driven to press the blank down until the head is formed.

[0018] Preferably, during the annealing treatment in step S4, the furnace temperature is ≤80°C, the heating rate is ≤100°C / h, and after the head is heat-insulated, the head is rapidly water-cooled in the same manner as quenching.

[0019] (3) Beneficial effects

[0020] The present invention provides an elliptical head forging and quenching process. Compared with the prior art, it has the following beneficial effects: the elliptical head forging and quenching process specifically includes the following steps: S1, ingot processing: take the required raw material steel ingot and use processing equipment to turn the edges and rust on its surface to make an ingot; S2, forging processing: transfer the ingot in step S1 to an electric arc furnace for forging, the forging temperature is 900-1300℃, and forge it into an elliptical head and take it out; S3, quenching processing: first arrange the exhaust pipe in the elliptical head formed in step S2, and then quench the head, first raise the temperature from room temperature to 600-800℃, keep warm for 5-20min, then raise the temperature from room temperature to 900-1300℃, keep warm for 10-20min, after keeping warm, open the door of the heat treatment furnace, use a sling to lift the elliptical head from the heat treatment furnace to the top of the quenching equipment, adjust The crane is in the driving position, so that the elliptical head is directly above the quenching and cooling device, and the crane falls to place the elliptical head into the quenching and cooling device. During this process, the gas in the inner cavity of the head is discharged through the exhaust pipe, and the high-speed water flow sprayed from the nozzle of the internal spray device quickly cools the inner surface of the head; S4, annealing treatment: the elliptical head after quenching is annealed, and after keeping warm for 10-20 minutes, it is naturally cooled to room temperature, and then the annealed elliptical head is clamped on the machine tool for machining, so as to obtain the elliptical head. By adopting the multi-nozzle spray cooling method, it can be achieved that the quenching and cooling can be well controlled, and the purpose of greatly improving the forging and quenching efficiency of the elliptical head by simplifying the specific forging and quenching treatment process is achieved, thereby greatly facilitating the forging and quenching treatment of the elliptical head. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0023] See also Figure 1 The embodiment of the present invention provides three technical solutions: an elliptical head forging and quenching process, specifically including the following embodiments:

[0024] Example 1: A forging and quenching process for an elliptical head, comprising the following steps:

[0025] S1. Ingot processing: Take the required raw steel ingot and use processing equipment to turn the edges and rust on its surface to make ingots. The processing equipment includes CNC lathes, CNC milling machines and CNC grinders;

[0026] S2, forging process: the ingot in step S1 is transferred to an electric arc furnace for forging at a forging temperature of 1100°C, and is forged into an elliptical head and taken out. The ingot forging process is specifically as follows: the ingot is placed in the groove on the die, and then the center line of the narrow anvil is aligned with the center line of the blank and the narrow anvil is driven to press down. After each pressing is completed, the die is driven to rotate the blank by a certain angle and then the narrow anvil is driven to press down the blank until the head is formed;

[0027] S3, quenching treatment: first arrange the exhaust pipe in the elliptical head formed in step S2, and then quench the head, first raise the temperature from room temperature to 700℃, keep it warm for 12 minutes, then raise it from room temperature to 1100℃, keep it warm for 15 minutes, after keeping warm, open the door of the heat treatment furnace, use the lifting device to lift the elliptical head from the heat treatment furnace to the top of the quenching equipment, adjust the position of the driving device so that the elliptical head is directly above the quenching cooling device, lower the driving device, and place the elliptical head into the quenching cooling device. During this process, the gas in the inner cavity of the head is discharged through the exhaust pipe, and the high-speed water flow sprayed from the nozzle of the internal spray device quenches the inner surface of the head. Rapid cooling, the exhaust pipe is arranged inside the elliptical head and welded inside the head. The air in the inner cavity of the head and the water vapor generated during quenching are discharged from the exhaust pipe. A steel pipe is used as the exhaust pipe. The exhaust pipe part outside the head is fixed to the outer surface of the head with reinforcement ribs. The heating rate from room temperature to 700℃ is 10℃ / min, the furnace temperature for annealing treatment is 750℃, and the holding time is 15h. During the quenching heat treatment process, the furnace temperature is ≤200℃ and the heating rate is ≤100℃ / h. When the quenching holding time is approaching, the high-pressure water pump connected to the main pipeline of the internal spray device is turned on to stir the water in the quenching water tank;

[0028] S4. Annealing treatment: anneal the quenched elliptical head, keep it warm for 15 minutes, and then cool it naturally to room temperature. Then clamp the annealed elliptical head on a machine tool for machining to obtain an elliptical head. During the annealing process, the furnace temperature is ≤80℃, and the heating rate is ≤100℃ / h. After the head is kept warm, it is quickly water-cooled in the same way as quenching.

[0029] Example 2: A forging and quenching process for an elliptical head, comprising the following steps:

[0030] S1. Ingot processing: Take the required raw steel ingot and use processing equipment to turn the edges and rust on its surface to make ingots. The processing equipment includes CNC lathes, CNC milling machines and CNC grinders;

[0031] S2, forging process: the ingot in step S1 is transferred to an electric arc furnace for forging at a forging temperature of 900°C, and is forged into an elliptical head and taken out. The specific process of the steel ingot forging is as follows: the steel ingot is placed in the groove on the die, and then the center line of the narrow anvil is aligned with the center line of the blank and the narrow anvil is driven to press down. After each pressing is completed, the die is driven to rotate the blank for a certain angle and then the narrow anvil is driven to press down the blank until the head is formed;

[0032] S3, quenching treatment: first arrange the exhaust pipe in the elliptical head formed in step S2, and then quench the head, first raise the temperature from room temperature to 600℃, keep it warm for 5 minutes, then raise it from room temperature to 900℃, keep it warm for 10 minutes, after keeping warm, open the door of the heat treatment furnace, use the lifting device to lift the elliptical head from the heat treatment furnace to the top of the quenching equipment, adjust the position of the driving device so that the elliptical head is directly above the quenching cooling device, lower the driving device, and place the elliptical head into the quenching cooling device. During this process, the gas in the inner cavity of the head is discharged through the exhaust pipe, and the high-speed water flow sprayed from the nozzle of the internal spray device quenches the inner surface of the head. Rapid cooling, the exhaust pipe is arranged inside the elliptical head and welded inside the head. The air in the inner cavity of the head and the water vapor generated during quenching are discharged from the exhaust pipe. A steel pipe is used as the exhaust pipe. The exhaust pipe part outside the head is fixed to the outer surface of the head with reinforcement ribs. The heating rate from room temperature to 600℃ is 5℃ / min, the furnace temperature for annealing treatment is 700℃, and the holding time is 10h. During the quenching heat treatment process, the furnace temperature is ≤200℃ and the heating rate is ≤100℃ / h. When the quenching holding time is approaching, the high-pressure water pump connected to the main pipeline of the internal spray device is turned on to stir the water in the quenching water tank;

[0033] S4. Annealing treatment: anneal the quenched elliptical head, keep it warm for 10 minutes and then cool it naturally to room temperature. Then clamp the annealed elliptical head on a machine tool for machining to obtain an elliptical head. During the annealing process, the furnace temperature is ≤80℃ and the heating rate is ≤100℃ / h. After the head is kept warm, it is quickly water-cooled in the same way as quenching.

[0034] Example 3: A forging and quenching process for an elliptical head, comprising the following steps:

[0035] S1. Ingot processing: Take the required raw steel ingot and use processing equipment to turn the edges and rust on its surface to make ingots. The processing equipment includes CNC lathes, CNC milling machines and CNC grinders;

[0036] S2, forging process: the ingot in step S1 is transferred to an electric arc furnace for forging at a forging temperature of 1300°C, and is forged into an elliptical head and taken out. The ingot forging process is specifically as follows: the ingot is placed in the groove on the die, and then the center line of the narrow anvil is aligned with the center line of the blank and the narrow anvil is driven to press down. After each pressing is completed, the die is driven to rotate the blank by a certain angle and then the narrow anvil is driven to press down the blank until the head is formed;

[0037] S3, quenching treatment: first arrange the exhaust pipe in the elliptical head formed in step S2, and then quench the head, first raise the temperature from room temperature to 800℃, keep it warm for 20 minutes, then raise it from room temperature to 1300℃, keep it warm for 20 minutes, after keeping it warm, open the door of the heat treatment furnace, use the lifting device to lift the elliptical head from the heat treatment furnace to the top of the quenching equipment, adjust the position of the driving device so that the elliptical head is directly above the quenching cooling device, lower the driving device, and place the elliptical head into the quenching cooling device. During this process, the gas in the inner cavity of the head is discharged through the exhaust pipe, and the high-speed water flow sprayed from the nozzle of the internal spray device quenches the inner surface of the head. Rapid cooling, the exhaust pipe is arranged inside the elliptical head and welded inside the head. The air in the inner cavity of the head and the water vapor generated during quenching are discharged from the exhaust pipe. A steel pipe is used as the exhaust pipe. The exhaust pipe part outside the head is fixed to the outer surface of the head with reinforcement ribs. The heating rate from room temperature to 800℃ is 15℃ / min. The furnace temperature of the annealing treatment is 800℃, and the holding time is 20h. During the quenching heat treatment process, the furnace temperature is ≤200℃ and the heating rate is ≤100℃ / h. When the quenching holding time is approaching, the high-pressure water pump connected to the main pipeline of the internal spray device is turned on to stir the water in the quenching water tank;

[0038] S4. Annealing treatment: anneal the quenched elliptical head, keep it warm for 20 minutes, and then cool it naturally to room temperature. Then clamp the annealed elliptical head on a machine tool for machining to obtain an elliptical head. During the annealing process, the furnace temperature is ≤80℃, and the heating rate is ≤100℃ / h. After the head is kept warm, it is quickly water-cooled in the same way as quenching.

[0039] In summary, the present invention can achieve good quenching cooling control by adopting a multi-nozzle spray cooling method, and well achieves the purpose of greatly improving the forging quenching efficiency of the elliptical head by simplifying the specific forging quenching process, thereby greatly facilitating the forging quenching treatment of the elliptical head.

[0040] Meanwhile, the contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0041] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0042] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A forging and quenching process for an elliptical head, characterized in that: The specific steps include: S1. Ingot processing: Take the required raw steel ingot and use processing equipment to turn the edges and rust on its surface to make ingot; S2, forging treatment: the ingot in step S1 is transferred to an electric arc furnace for forging at a forging temperature of 900-1300°C, and is forged into an elliptical head and taken out; S3, quenching treatment: first arrange the exhaust pipe in the elliptical head formed in step S2, and then quench the head, first raise the temperature from room temperature to 600-800℃, keep it warm for 5-20 minutes, then raise it from room temperature to 900-1300℃, keep it warm for 10-20 minutes. After keeping warm, open the door of the heat treatment furnace, use a lifting device to lift the elliptical head from the heat treatment furnace to the top of the quenching equipment, adjust the position of the driving device so that the elliptical head is directly above the quenching cooling device, lower the driving device, and place the elliptical head into the quenching cooling device. During this process, the gas in the inner cavity of the head is discharged through the exhaust pipe, and the high-speed water flow sprayed from the nozzle of the internal spray device quickly cools the inner surface of the head; S4. Annealing treatment: annealing the quenched elliptical head, keeping it warm for 10-20 minutes and then naturally cooling it to room temperature. Then, clamping the annealed elliptical head on a machine tool for machining, thereby obtaining an elliptical head.

2. The elliptical head forging and quenching process according to claim 1, characterized in that: The processing equipment in step S1 includes a CNC lathe, a CNC milling machine and a CNC grinder.

3. The elliptical head forging and quenching process according to claim 1, characterized in that: In step S3, the exhaust pipe is arranged inside the elliptical head by welding the exhaust pipe inside the head. The air in the inner cavity of the head and the water vapor generated during quenching are discharged from the exhaust pipe. A steel pipe is used as the exhaust pipe, and the exhaust pipe part outside the head is fixed to the outer surface of the head with reinforcing ribs.

4. The elliptical head forging and quenching process according to claim 1, characterized in that: In step S3, the heating rate from room temperature to 600-800° C. is 5-15° C. / min.

5. The elliptical head forging and quenching process according to claim 1, characterized in that: The furnace temperature for the annealing treatment in step S3 is 700-800° C., and the holding time is 10-20 hours.

6. The elliptical head forging and quenching process according to claim 1, characterized in that: During the quenching heat treatment in step S3, the charging temperature is ≤200°C, the heating rate is ≤100°C / h, and when the quenching holding time is approaching, the high-pressure water pump connected to the main pipeline of the internal spray device is turned on to stir the water in the quenching water tank.

7. The elliptical head forging and quenching process according to claim 1, characterized in that: The steel ingot forging process in step S2 is specifically as follows: placing the steel ingot into the groove on the die, then aligning the center line of the narrow anvil with the center line of the blank and driving the narrow anvil to press down. After each pressing is completed, the die is driven to drive the blank to rotate a certain angle and then the narrow anvil is driven to press the blank down until the head is formed.

8. The elliptical head forging and quenching process according to claim 1, characterized in that: During the annealing process in step S4, the furnace temperature is ≤80°C, the heating rate is ≤100°C / h, and after the head is kept warm, the head is quickly water-cooled in the same manner as the quenching cooling.

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