Manufacturing method of fracturing pump head with long service life

Abstract

The invention relates to a manufacturing method of a long-service-life fracturing pump head, and belongs to the technical field of fracturing pump head manufacturing. Comprising the following steps of S01 blank preparation, S02 die assembly, S03 blank forging, S04 discharging and S05 heat treatment. A multidirectional die forging mode is adopted, the internal structure is uniform and compact, the mechanical performance is within a stable range, the phenomenon of fluctuation is avoided, and the impact stress and the fatigue speed are greatly reduced. The service life of the product is prolonged by 20%-80%, and the problems that the pump head product is unstable and the service life is different are solved.

Description

Technical Field

[0001] This application belongs to the technical field of the manufacture of fracturing pump heads, and specifically relates to a manufacturing method for long-life fracturing pump heads. Background Art

[0002] In the manufacturing scheme of pressure pump heads, free forging has always been used to form a free hexahedron. During the free forging process, the steel is in an open space. On the surface of the steel struck by the forging hammer, the steel deforms in the striking direction. After three forging and two drawing processes. However, due to the forging being in an open space, the volume of the forging body is large, basically in the range of 600×600×(1300 - 2000). There are certain limitations in further refining the grains, eliminating defects such as pores and looseness of the forgings, resulting in a large deviation in the compactness of the core structure. In subsequent heat treatments, it is manifested as large variations in the tensile strength, yield strength, and impact energy of the core. The hardness difference between the surface and the core can be more than 50 HRB. Due to the mechanical properties, the tensile strength changes by more than 30%, and the impact energy also changes by more than 30%. This causes the pump head to generate fatigue cracks at an accelerated rate under the action of alternating stress during use, reducing its lifespan. Due to the different temperatures, striking forces, speeds, and directions of the steel during the free forging process, the internal structure changes greatly. Products of the same batch have very different lifespans under the same usage environment. Taking alloy steel as an example, the low lifespan is only over 100 hours, and the high lifespan can reach over 800 hours. The short lifespan and non-uniformity have a huge impact on users. Summary of the Invention

[0003] The technical problem to be solved by this application is: overcoming the deficiencies of the prior art, providing a manufacturing method for long-life fracturing pump heads. This application adopts a multi-directional die forging method, with a uniform and dense internal structure, mechanical properties within a stable range, without significant fluctuations, greatly reducing the impact stress and fatigue rate. The lifespan of the product is increased by 20% - 80%, solving the pain points of unstable pump head products and large differences in lifespan.

[0004] The technical solution adopted by this application to solve the problems existing in the prior art is:

[0005] A manufacturing method for long-life fracturing pump heads, comprising the following steps:

[0006] S01. Prepare the blank;

[0007] S02. Close the die:

[0008] The closed die installed on the multi-directional die forging hydraulic press wraps the blank by horizontal clamping;

[0009] The multi-directional die forging hydraulic press is equipped with two horizontal working cylinders to achieve two-way synchronous extrusion, and one working cylinder is arranged in the vertical direction;

[0010] S03. Blank forging:

[0011] Through holes are provided on the horizontal end face and the top face of the closed die. The forging head of the working cylinder of the multi-directional forging hydraulic press is matched with the through holes. The forging heads of the horizontal working cylinders of the multi-directional forging hydraulic press simultaneously enter the inside of the closed die through the through holes on the horizontal end face of the closed die to forge the blank, and at the same time, forging holes in the horizontal direction are formed on the horizontal end face of the blank.

[0012] After the forging heads of the multi-directional forging hydraulic press in the horizontal direction are in place, the forging heads in the vertical direction press down, pass through the through holes on the top face of the closed die and enter the inside of the closed die to forge the blank, and at the same time, forging holes in the vertical direction are formed on the blank.

[0013] S04. Discharging;

[0014] S05. Heat treatment.

[0015] Preferably, the blank is prepared according to the inner cavity size of the closed die. In the hot state, the volume of the blank is less than or equal to the inner cavity volume of the closed die.

[0016] Preferably, the volume of the blank is controlled by the weight of the blank. The relationship between the actual weight W of the blank and the standard weight W0 is as follows:

[0017] 0.95*W0 ≤ W ≤ 1.04*W0

[0018] Preferably, when closing the die, the blank is heated to 1100°C to 1200°C, and the closed die is preheated to 250°C to 350°C.

[0019] Preferably, in step S03, the overall forging pressure is 2000 to 3000 MPa, and the pressure is stabilized for 0.5 to 2 minutes.

[0020] Preferably, the actual feed of the forging heads of the multi-directional forging hydraulic press in the horizontal and vertical directions is related to the actual weight of the blank. The relationship between the two is as follows:

[0021]

[0022] Where d1 is the travel distance of the forging head of the multi-directional forging hydraulic press in the vertical direction when the weight of the blank is W;

[0023] d ' 1 is the travel distance of the forging head of the multi-directional forging hydraulic press in the vertical direction when the weight of the blank is W0;

[0024] Where d2 is the travel distance of the forging head of the multi-directional forging hydraulic press in the horizontal direction when the weight of the blank is W;

[0025] d ' 2 is the travel distance of the forging head of the multi-directional forging hydraulic press in the horizontal direction when the weight of the blank is W0;

[0026] where β is the correction coefficient.

[0027] Preferably, in step S05, the conditioning treatment is carried out by quenching and high-temperature tempering.

[0028] Preferably, the quenching temperature is 830 to 860 °C, and oil cooling is adopted;

[0029] The tempering temperature is 550 to 650 °C, the holding time is 2 to 3 hours, and air cooling is adopted.

[0030] Compared with the prior art, the beneficial effects of the present application are as follows:

[0031] (1) By adopting the multi-directional forging method, the internal structure of the forging is uniform and dense, and the mechanical properties are within a stable range. The hardness fluctuation value in different regions of the same workpiece shall not exceed 20 units, increasing the product life by 20% to 80%, solving the pain points of unstable pump head products and widely varying product lives.

[0032] (2) The feed amount of the forging heads in two directions of the multi-directional forging hydraulic press is automatically adjusted according to the weight of the blank, ensuring that the blank fills the closed die completely. After forging, the outer shape of the blank is exactly the same as the shape of the closed die cavity. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present application will be further described below in conjunction with the drawings and embodiments.

[0034] Figure 1 It is a flowchart of the manufacturing method of a long-life fracturing pump head of the present application, DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] The manufacturing method of a long-life fracturing pump head of the present application will be further described in detail below in conjunction with the drawings, but it is not a limitation to the present application.

[0036] A manufacturing method of a long-life fracturing pump head includes the following steps:

[0037] S01. Prepare the blank:

[0038] Prepare the blank according to the inner cavity size of the closed die. In the hot state, the volume of the blank is less than or equal to the inner cavity volume of the closed die;

[0039] Control the volume of the blank by the weight of the blank. The relationship between the actual weight W of the blank and the standard weight W0 is as follows:

[0040] 0.95 * W0 ≤ W ≤ 1.04 * W0

[0041] S02. Close the die:

[0042] The blank is heated to 1100°C to 1200°C, and the closed die is preheated to 250°C to 350°C. The closed die installed on the multi-directional die forging hydraulic press wraps the blank by means of horizontal clamping.

[0043] The multi-directional die forging hydraulic press is equipped with two horizontal working cylinders to achieve two-way synchronous extrusion, and a working cylinder is arranged in the vertical direction. The closed die is connected to the multi-directional die forging hydraulic press by means of horizontal die splitting, that is, the movable crossbeam of the multi-directional die forging hydraulic press cooperates with the concave die lifting system to realize automatic die opening and closing and forging ejection.

[0044] S03. Blank forging:

[0045] Through holes are provided on the horizontal end face and the top face of the closed die, and the forging heads of the working cylinders of the multi-directional die forging hydraulic press are matched with the through holes. The forging heads of the horizontal working cylinders of the multi-directional die forging hydraulic press simultaneously enter the inside of the closed die through the through holes on the horizontal end face of the closed die to forge the blank, and at the same time, horizontal forging holes are formed on the horizontal end face of the blank.

[0046] After the forging heads of the horizontal direction of the multi-directional die forging hydraulic press are in place, the forging head in the vertical direction presses down, passes through the through hole on the top face of the closed die and enters the inside of the closed die to forge the blank, and at the same time, vertical forging holes are formed on the blank.

[0047] The overall forging pressure is 2000 to 3000 MPa, and the pressure is stabilized for 0.5 to 2 minutes to realize the refinement of the grains of the whole blank, the disappearance of defects, and the whole blank reaches a uniform density body.

[0048] The actual feed of the forging heads of the multi-directional die forging hydraulic press in the horizontal and vertical directions is related to the actual weight of the blank, and the relationship between the two is as follows:

[0049]

[0050] Where d1 is the travel distance of the forging head in the vertical direction of the multi-directional die forging hydraulic press when the weight of the blank is W;

[0051] d ' 1 is the travel distance of the forging head in the vertical direction of the multi-directional die forging hydraulic press when the weight of the blank is W0;

[0052] Where d2 is the travel distance of the forging head in the horizontal direction of the multi-directional die forging hydraulic press when the weight of the blank is W;

[0053] d ' 2 is the travel distance of the forging head in the horizontal direction of the multi-directional die forging hydraulic press when the weight of the blank is W0;

[0054] Where β is the correction coefficient.

[0055] S04. Discharging:

[0056] The closed die separates, and the multi-directional die forging hydraulic press ejects the forging, and the operator transfers it to the heat treatment process.

[0057] S05. Heat treatment:

[0058] Modulation treatment is carried out by quenching plus high-temperature tempering. The quenching temperature is 830 to 860 °C, and oil cooling is adopted. The tempering temperature is 550 to 650 °C, and the holding time is 2 to 3 hours, and air cooling is adopted. After the heat treatment process, the tensile strength of the forging reaches more than 1000 MPa, and the yield strength is more than 850 MPa. When the impact test is carried out in a low-temperature environment of -40 °C, the absorbed impact energy value ≥ 60 J. The hardness HRB deviation ≤ 20 HRB, that is, the hardness fluctuation value in different regions of the same workpiece shall not exceed 20 units.

[0059] The embodiments of the present application have been described in detail above with reference to the accompanying drawings. However, the present application is not limited to the above embodiments, and various changes can be made without departing from the purpose of the present application within the knowledge scope of those of ordinary skill in the art.

Claims

1. A manufacturing method of a long-life fracturing pump head, characterized in that, It includes the following steps: S01. Prepare the blank; S02. Close the die: The closed die installed on the multi-directional forging hydraulic press wraps the blank by means of horizontal clamping; The multi-directional forging hydraulic press is equipped with two horizontal working cylinders to achieve two-way synchronous extrusion, and one working cylinder is arranged in the vertical direction; S03. Forge the blank: The horizontal end face and the top surface of the closed die are provided with through holes, and the forging heads of the working cylinders of the multi-directional forging hydraulic press are matched with the through holes. The forging heads of the horizontal working cylinders of the multi-directional forging hydraulic press simultaneously enter the inside of the closed die through the through holes on the horizontal end face of the closed die to forge the blank, and at the same time, horizontal forging holes are formed on the horizontal end face of the blank; After the forging heads in the horizontal direction of the multi-directional forging hydraulic press are in place, the forging heads in the vertical direction press down, pass through the through holes on the top surface of the closed die and enter the inside of the closed die to forge the blank, and at the same time, vertical forging holes are formed on the blank; S04. Discharge the material; S05. Heat treatment.

2. The manufacturing method of a long-life fracturing pump head according to claim 1, wherein: Prepare the blank according to the inner cavity size of the closed die. In the hot state, the volume of the blank is less than or equal to the inner cavity volume of the closed die.

3. The manufacturing method of a long-life fracturing pump head according to claim 1, wherein: Control the volume of the blank by the weight of the blank. The relationship between the actual weight W of the blank and the standard weight W0 is as follows: 0.95*W0 ≤ W ≤ 1.04*W 0。 4. The manufacturing method of a long-life fracturing pump head according to claim 1, wherein: When closing the die, heat the blank to 1100°C to 1200°C, and preheat the closed die to 250°C to 350°C.

5. The manufacturing method of a long-life fracturing pump head according to claim 3, wherein: In step S03, the overall forging pressure is 2000 to 3000 MPa, and the pressure is stabilized for 0.5 to 2 minutes.

6. The manufacturing method of a long-life fracturing pump head according to claim 3 or 5, wherein: The actual feed of the forging heads in the horizontal and vertical directions of the multi-directional forging hydraulic press is related to the actual weight of the blank. The relationship between the two is as follows: Where d1 is the travel distance of the forging head in the vertical direction of the multi-directional forging hydraulic press when the weight of the blank is W; d ' 1 is the travel distance of the forging head in the vertical direction of the multi-directional die forging hydraulic press when the blank weight is W0; Where d2 is the travel distance of the forging head in the horizontal direction of the multi-directional forging hydraulic press when the weight of the blank is W; d ' 2 is the travel distance of the horizontal forging head of the multi-directional die forging hydraulic press when the blank weight is W0; Where β is the correction coefficient.

7. The manufacturing method of a long-life fracturing pump head according to any one of claims 1 to 5, characterized in that: In step S05, tempering treatment is carried out by quenching plus high-temperature tempering.

8. The manufacturing method of a long-life fracturing pump head according to claim 7, wherein: The quenching temperature is 830 to 860°C, and oil cooling is used; The tempering temperature is 550 to 650°C, the heat preservation time is 2 to 3 hours, and air cooling is used.

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