A method for preparing a shale gas hydraulic end pump head body

Abstract

The present invention discloses a method for preparing a shale gas hydraulic end pump head body, comprising the following steps: primary forging heating - I fire forging - secondary forging heating - II fire forging - tertiary forging heating - III fire forging - quaternary forging heating - IV fire - post-forging heat treatment. In the present invention, by increasing the primary forging heating, secondary forging heating temperature and lateral deformation, the atomic diffusion capacity is enhanced, the internal components are homogenized, the low-temperature impact energy of the material is effectively improved, and the lateral and longitudinal impact energy are closer.

Description

Technical Field

[0001] The invention relates to the field of pump head bodies, and in particular to a method for preparing a shale gas hydraulic end pump head body. Background Art

[0002] The pump head body is used to work in a corrosive fatigue environment and is usually made of 15-5PH precipitation hardened stainless steel.

[0003] The working conditions of the fracturing pump used in shale oil and gas exploitation are harsh. The pump head body is subjected to high pressure, alternating stress, and is also exposed to corrosion and wear of acid medium and sand. This requires that the material used to manufacture the pump head body must be corrosion-resistant and have high toughness. However, due to the large forging of the pump head body, the forging material is seriously uneven, and banded structures or serious mixed crystals often appear. When subjected to large external forces, the uneven deformation causes great internal stress, which can easily cause corrosion fatigue cracks and failure, resulting in a short service life of the pump head body. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing a shale gas hydraulic end pump head body.

[0005] The innovation of the present invention is that the problem of uneven internal material of the pump head body is solved by changing the forging process, which effectively improves the low-temperature impact energy of the material and makes the transverse and longitudinal impact energies closer, thereby greatly extending the service life of the pump head body.

[0006] To achieve the above-mentioned purpose of the invention, the technical solution of the present invention is: a method for preparing a shale gas hydraulic end pump head body, comprising the following steps:

[0007] (1) Primary forging heating: After the electroslag ingot is kept at 450-650°C for 2-6 hours, it is heated to 850°C at a rate of 70°C / h or less and kept at 850°C for 2-8 hours, and then heated to 1210-1230°C at a rate of 100°C / h or less and kept at 1210-1230°C for 8-12 hours to obtain a primary heated electroslag ingot;

[0008] (2) Ⅰ Fire Forging:

[0009] Place the once heated electroslag ingot on the hydraulic press for forging, lightly press the outer circle of the once heated electroslag ingot, stand the once heated electroslag ingot upright and place it on the walkway of the hydraulic press, upset it in stages along the axial direction of the once heated electroslag ingot to half of its original height, flatten it along its axial direction to a thickness: width: length ratio of 1:1.5~2:1.5~2 to obtain a billet, press the edges and corners perpendicular to the length direction of the billet at both ends of the billet into fillets with a radius of 80~100mm; then deform it transversely, make the width direction of the billet parallel to the downward pressing direction of the hydraulic press, make the length direction of the anvil of the hydraulic press parallel to the length direction of the billet, forge the width dimension of the billet after deformation into the thickness dimension of the billet before deformation, forge the thickness dimension of the billet after deformation into the width dimension of the billet before deformation, and then forge it along the axial direction of the original once heated electroslag ingot into a cylindrical shape with a height-to-diameter ratio of 2:1 to obtain a first-fire billet;

[0010] (3) Secondary forging heating: Load the first-heat billet into a heating furnace, heat it to 1210-1230°C, and keep it at 1210-1230°C for 12-20 hours to obtain a secondary heated billet;

[0011] (4) II-fire forging: The secondary heated billet is placed vertically on the walkway of the hydraulic press, and the secondary heated billet is upset in batches along the axis direction of the secondary heated billet to half of its original height, and then it is flattened along the axis direction to a thickness: width: length ratio of 1:1.5~2:1.5~2 to obtain a prefabricated II-fire billet, and the edges and corners of the two ends of the prefabricated II-fire billet perpendicular to the axis of the secondary heated billet are pressed into fillets with a radius of 80~100mm; Then, the prefabricated Ⅱ-fired blank is subjected to transverse deformation, the width direction of the prefabricated Ⅱ-fired blank is parallel to the downward pressing direction of the hydraulic press, the length direction of the hydraulic press anvil is parallel to the length direction of the blank, the width dimension of the prefabricated Ⅱ-fired blank after deformation is forged into the thickness dimension of the prefabricated Ⅱ-fired blank before deformation, and the thickness dimension of the prefabricated Ⅱ-fired blank after deformation is forged into the width dimension of the prefabricated Ⅱ-fired blank before deformation; and then, it is forged along the axis direction of the original once-heated electroslag ingot into a cylindrical shape with a height-to-diameter ratio of 2:1 to obtain a Ⅱ-fired blank;

[0012] (5) Three-time forging heating: Load the II-fired billet into a heating furnace, heat it to 1100-1180°C and keep it at 1100-1180°C for 2-5 hours to obtain a three-time heated billet;

[0013] (6) III-fire forging: The tertiary heated blank is placed vertically on the walkway of the hydraulic press, and the tertiary heated blank is upset in batches along the axis direction to half of the original height of the tertiary heated blank, and then stretched along the axis. The stretched length is 50-70% of the required pump head body blank forging length, and the III-fire blank is obtained;

[0014] (7) Four-time forging heating: Load the III-fired blank into a heating furnace, heat it to 1080-1120°C, and keep it at 1080-1120°C for 2-5 hours to obtain a four-time heated blank;

[0015] (8) IV Fire: The fourth-heated blank is stretched along the axial direction of the fourth-heated blank to forge the pump head body blank forging.

[0016] (9) Post-forging heat treatment: Heat the pump head body blank forging to 1050°C and keep it at 1050°C for 2 to 6 hours, then heat it to 1030~1050°C at a rate of 40~80°C / h and keep it at this temperature for 10~20 hours, then quickly air cool it to room temperature, then heat it to 550~600°C at a rate of 40~80°C / h and keep it at this temperature for 18~30 hours, then quickly air cool it to room temperature to obtain the finished product.

[0017] Furthermore, in the step (1), the electroslag ingot is kept at 550° C. for 2 to 6 hours.

[0018] Furthermore, the anvil of the hydraulic press comprises an anvil body, and slope surfaces are arranged on both sides of the working surface of the anvil body, and the slope surfaces are composed of two arcs and a tangent connecting the two arcs.

[0019] Furthermore, the thickness of the anvil body is 650~700mm.

[0020] The beneficial effects of the present invention are:

[0021] 1. In the present invention, by increasing the primary forging heating temperature and the secondary forging heating temperature, the atomic diffusion capacity is enhanced, the internal components are homogenized, and the segregation problem of the material is effectively improved.

[0022] 2. In the present invention, the temperature reduction forging of three forging heating and four forging heating is used to refine the grains and improve the strength and toughness of the material.

[0023] 3. In the present invention, by adding a transverse deformation process during the I fire forging and the II fire forging, the uniformity of the material is improved, making the material more dense and uniform.

[0024] 4. The present invention rounds the end to solve the problem of edge cracking during forging. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present invention will be described clearly and completely below.

[0026] Embodiment 1: A method for preparing a shale gas hydraulic end pump head body, comprising the following steps:

[0027] (1) Primary forging heating: After the electroslag ingot is kept at 450°C for 2 hours, it is heated to 850°C at a rate of 70°C / h and kept at 850°C for 2 hours, and then heated to 1210°C at a rate of 100°C / h and kept at 1210°C for 8 hours to obtain a primary heated electroslag ingot;

[0028] (2) Ⅰ Fire Forging:

[0029] Place the once heated electroslag ingot on the hydraulic press for forging, lightly press the outer circle of the once heated electroslag ingot, stand it upright and place it on the walkway of the hydraulic press, upset it in stages along the axial direction of the once heated electroslag ingot to half of its original height, flatten it along its axial direction to a thickness: width: length ratio of 1:1.5:1.5 to obtain a billet, press the edges and corners at both ends of the billet perpendicular to the length direction of the billet into fillets with a radius of 80mm; then deform it transversely, and make the billet in the width direction and the downward pressing direction of the hydraulic press square. The anvil of the hydraulic press is parallel to the length direction of the billet, the width dimension of the deformed billet is forged into the thickness dimension of the billet before deformation, and the thickness dimension of the deformed billet is forged into the width dimension of the billet before deformation, and then it is forged into a cylindrical shape with a height-to-diameter ratio of 2:1 along the axial direction of the original once-heated electroslag ingot to obtain a Type I fire billet; the anvil of the hydraulic press comprises an anvil body, and slopes are arranged on both sides of the working surface of the anvil body, the slopes are composed of two arcs and a tangent connecting the two arcs, and the thickness of the anvil body is 650mm.

[0030] (3) Secondary forging heating: Load the first-heat billet into a heating furnace, heat it to 1210°C and keep it at 1210°C for 12 hours to obtain a secondary heated billet;

[0031] (4) II-fire forging: The secondary heated billet is placed vertically on the walkway of the hydraulic press, and the secondary heated billet is upset in batches along the axial direction of the secondary heated billet to half of its original height, and then it is flattened along the axial direction to a thickness: width: length ratio of 1:1.5:1.5 to obtain a prefabricated II-fired billet, and the edges and corners of the two ends of the prefabricated II-fired billet perpendicular to the axis of the secondary heated billet are pressed into fillets with a radius of 80 mm; then it is transversely deformed, the width direction of the prefabricated II-fired billet is parallel to the downward pressing direction of the hydraulic press, the length direction of the hydraulic press anvil is parallel to the length direction of the billet, the width dimension of the prefabricated II-fired billet after deformation is forged into the thickness dimension of the prefabricated II-fired billet before deformation, and the thickness dimension of the prefabricated II-fired billet after deformation is forged into the width dimension of the prefabricated II-fired billet before deformation; then it is forged along the axial direction of the original once heated electroslag ingot into a cylindrical shape with a height-to-diameter ratio of 2:1 to obtain a II-fired billet;

[0032] (5) Three-time forging heating: The II-fired billet is loaded into a heating furnace, heated to 1100°C and kept at 1100°C for 2 hours to obtain a three-time heated billet;

[0033] (6) III-fire forging: The tertiary heated blank is placed vertically on the walkway of the hydraulic press, and the tertiary heated blank is upset in batches along the axis direction to half of the original height of the tertiary heated blank, and then stretched along the axis. The stretched length is 50-70% of the required pump head body blank forging length, and the III-fire blank is obtained;

[0034] (7) Four-time forging heating: Load the III-fired blank into a heating furnace, heat it to 1080°C and keep it at 1080°C for 2 hours to obtain a four-time heated blank;

[0035] (8) IV Fire: The fourth-heated blank is stretched along the axial direction of the fourth-heated blank to forge the pump head body blank forging.

[0036] (9) Heat treatment: The pump head body blank forging is heated to 1040°C and kept at 1040°C for 25 hours, then quickly air-cooled to room temperature. The temperature is then increased to 568°C at a rate of 40°C / h and kept at this temperature for 27 hours, then quickly air-cooled to room temperature to obtain the finished product.

[0037] Embodiment 2: A method for preparing a shale gas hydraulic end pump head body, comprising the following steps:

[0038] (1) Primary forging heating: After the electroslag ingot is kept at 550°C for 4 hours, it is heated to 850°C at a rate of 65°C / h and kept at 850°C for 5 hours, and then heated to 1220°C at a rate of 95°C / h and kept at 1220°C for 10 hours to obtain a primary heated electroslag ingot;

[0039] (2) Ⅰ Fire Forging:

[0040] Place the once heated electroslag ingot on the hydraulic press for forging, lightly press the outer circle of the once heated electroslag ingot, stand the once heated electroslag ingot upright and place it on the walkway of the hydraulic press, upset it in stages along the axial direction of the once heated electroslag ingot to half of its original height, and then flatten it along its axial direction to a thickness: width: length ratio of 1:1.8:1.8 to obtain a billet, press the edges and corners at both ends of the billet perpendicular to the length direction of the billet into fillets with a radius of 90mm; then deform it transversely, and align the width direction of the billet with the downward pressing direction of the hydraulic press. The anvil of the hydraulic press is parallel to the length direction of the billet, the width dimension of the deformed billet is forged into the thickness dimension of the billet before deformation, and the thickness dimension of the deformed billet is forged into the width dimension of the billet before deformation, and then it is forged into a cylindrical shape with a height-to-diameter ratio of 2:1 along the axial direction of the original once-heated electroslag ingot to obtain a Type I fire billet; the anvil of the hydraulic press comprises an anvil body, and slope surfaces are provided on both sides of the working surface of the anvil body, the slope surfaces are composed of two arcs and a tangent connecting the two arcs, and the thickness of the anvil body is 680mm.

[0041] (3) Secondary forging heating: Load the first-heat billet into a heating furnace, heat it to 1220°C and keep it at 1220°C for 16 hours to obtain a secondary heated billet;

[0042] (4) II-fire forging: The secondary heated billet is placed vertically on the walkway of the hydraulic press, and the secondary heated billet is upset in batches along the axial direction of the secondary heated billet to half of its original height, and then it is flattened along the axial direction to a thickness: width: length ratio of 1:1.8:1.8 to obtain a prefabricated II-fire billet, and the edges and corners of the two ends of the prefabricated II-fire billet perpendicular to the axis of the secondary heated billet are pressed into fillets with a radius of 90 mm; then it is transversely deformed, the width direction of the prefabricated II-fire billet is parallel to the downward pressing direction of the hydraulic press, the length direction of the hydraulic press anvil is parallel to the length direction of the billet, the width dimension of the prefabricated II-fire billet after deformation is forged into the thickness dimension of the prefabricated II-fire billet before deformation, and the thickness dimension of the prefabricated II-fire billet after deformation is forged into the width dimension of the prefabricated II-fire billet before deformation; then it is forged along the axial direction of the original once heated electroslag ingot into a cylindrical shape with a height-to-diameter ratio of 2:1 to obtain a II-fire billet;

[0043] (5) Three-time forging heating: The second-fired billet is loaded into a heating furnace, heated to 1160°C and kept at 1160°C for 3 hours to obtain a three-time heated billet;

[0044] (6) III-fire forging: The tertiary heated blank is placed vertically on the walkway of the hydraulic press, and the tertiary heated blank is upset in batches along the axis direction to half of the original height of the tertiary heated blank, and then stretched along the axis. The stretched length is 50-70% of the required pump head body blank forging length, and the III-fire blank is obtained;

[0045] (7) Four-time forging heating: Load the III-fired blank into a heating furnace, heat it to 1100°C and keep it at 1100°C for 3 hours to obtain a four-time heated blank;

[0046] (8) IV Fire: The fourth-heated blank is stretched along the axial direction of the fourth-heated blank to forge the pump head body blank forging.

[0047] (9) Heat treatment: The pump head body blank forging was heated to 1040°C and kept at 1040°C for 25 hours. It was quickly air-cooled to room temperature, and then heated to 570°C at a rate of 60°C / h and kept at this temperature for 24 hours. It was then quickly air-cooled to room temperature to obtain the finished product.

[0048] Embodiment 3: A method for preparing a shale gas hydraulic end pump head body, comprising the following steps:

[0049] (1) Primary forging heating: After the electroslag ingot is kept at 650°C for 6 hours, it is heated to 850°C at a rate of 60°C / h and kept at 850°C for 8 hours, and then heated to 1225°C at a rate of 90°C / h and kept at 1225°C for 12 hours to obtain a primary heated electroslag ingot;

[0050] (2) Ⅰ Fire Forging:

[0051] Place the once heated electroslag ingot on the hydraulic press for forging, lightly press the outer circle of the once heated electroslag ingot, and vertically place the once heated electroslag ingot on the walkway of the hydraulic press. Upset it in stages along the axis direction of the once heated electroslag ingot to half of its original height, and then flatten it along the axis direction until the length ratio of thickness: width: length is 1: 2: 2. Obtain a blank, press the edges and corners of both ends of the blank perpendicular to the length direction of the blank into fillets with a radius of 100 mm; then deform it transversely, make the width direction of the blank parallel to the downward pressing direction of the hydraulic press, and the length direction of the hydraulic press anvil is parallel to the length direction of the blank, forge the width dimension of the deformed blank into the thickness dimension of the blank before deformation, and forge the thickness dimension of the deformed blank into the width dimension of the blank before deformation, and then forge it along the axis direction of the original once heated electroslag ingot into a cylindrical shape with a height-to-diameter ratio of 2:1 to obtain a first-fire blank; the hydraulic press anvil includes an anvil body, and slopes are provided on both sides of the working surface of the anvil body, and the slopes are composed of two arcs and a tangent connecting the two arcs, and the thickness of the anvil body is 650-700 mm.

[0052] (3) Secondary forging heating: The first-heated billet is loaded into a heating furnace, heated to 1225°C and kept at 1225°C for 20 hours to obtain a secondary heated billet;

[0053] (4) II-fire forging: the secondary heated billet is placed vertically on the walkway of the hydraulic press, and the secondary heated billet is upset in stages along the axis direction of the secondary heated billet to half of its original height, and then it is flattened along the axis direction to a thickness: width: length ratio of 1:2:2 to obtain a prefabricated II-fired billet, and the edges and corners of the two ends of the prefabricated II-fired billet perpendicular to the axis of the secondary heated billet are pressed into fillets with a radius of 100 mm; then it is transversely deformed, the width direction of the prefabricated II-fired billet is parallel to the downward pressing direction of the hydraulic press, the length direction of the hydraulic press anvil is parallel to the length direction of the billet, the width dimension of the prefabricated II-fired billet after deformation is forged into the thickness dimension of the prefabricated II-fired billet before deformation, and the thickness dimension of the prefabricated II-fired billet after deformation is forged into the width dimension of the prefabricated II-fired billet before deformation; then it is forged along the axis direction of the original once heated electroslag ingot into a cylindrical shape with a height-to-diameter ratio of 2:1 to obtain a II-fired billet;

[0054] (5) Three-time forging heating: The Ⅱ-fired billet is loaded into a heating furnace, heated to 1180°C and kept at 1180°C for 5 hours to obtain a three-time heated billet;

[0055] (6) III-fire forging: The tertiary heated blank is placed vertically on the walkway of the hydraulic press, and the tertiary heated blank is upset in batches along the axis direction to half of the original height of the tertiary heated blank, and then stretched along the axis. The stretched length is 50-70% of the required pump head body blank forging length, and the III-fire blank is obtained;

[0056] (7) Four-time forging heating: The III-fired blank is placed in a heating furnace, heated to 1120°C and kept at 1120°C for 5 hours to obtain a four-time heated blank;

[0057] (8) IV Fire: The fourth-heated blank is stretched along the axial direction of the fourth-heated blank to forge the pump head body blank forging.

[0058] (9) Heat treatment: The pump head body blank forging is heated to 1040°C and kept at 1040°C for 22 hours, then quickly air-cooled to room temperature, and then heated to 565°C at a rate of 80°C / h and kept at this temperature for 26 hours, and then quickly air-cooled to room temperature to obtain the finished product.

[0059] Comparative Example: A method for preparing a shale gas hydraulic end pump head body, comprising the following steps:

[0060] (1) Primary forging heating: After the electroslag ingot is kept at 450°C for 2 hours, it is heated to 850°C at a rate of 70°C / h and kept at 850°C for 2 hours, and then heated to 1200°C at a rate of 100°C / h and kept at 1200°C for 6 hours to obtain a primary heated electroslag ingot;

[0061] (2) Ⅰ Fire Forging:

[0062] The once heated electroslag ingot is placed on a hydraulic press for forging, the outer circle of the once heated electroslag ingot is lightly pressed, the once heated electroslag ingot is erected and placed vertically on the walkway of the hydraulic press, and upset in stages along the axial direction of the once heated electroslag ingot to half of its original height, and then forged along the axial direction of the original once heated electroslag ingot into a cylindrical shape with a height-to-diameter ratio of 2:1 to obtain a Type I fire blank; the hydraulic press anvil includes an anvil body, and slopes are provided on both sides of the working surface of the anvil body, the slopes are composed of two arcs and a tangent connecting the two arcs, and the thickness of the anvil body is 650mm.

[0063] (3) Secondary forging heating: The first-heated billet is loaded into a heating furnace, heated to 1200°C and kept at 1200°C for 5 hours to obtain a secondary heated billet;

[0064] (4) II-fire forging: The secondary heated billet is placed vertically on the walkway of the hydraulic press, and the secondary heated billet is upset in stages along the axis direction of the secondary heated billet to half of its original height, and then it is forged along the axis direction of the original primary heated electroslag ingot into a cylindrical shape with a height-to-diameter ratio of 2:1 to obtain the II-fire billet;

[0065] (5) Three-time forging heating: The II-fired billet is loaded into a heating furnace, heated to 1200°C and kept at 1200°C for 4 hours to obtain a three-time heated billet;

[0066] (6) III-fire forging: The tertiary heated blank is placed vertically on the walkway of the hydraulic press, and the tertiary heated blank is upset in batches along the axis direction to half of the original height of the tertiary heated blank, and then stretched along the axis. The stretched length is 50-70% of the required pump head body blank forging length, and the III-fire blank is obtained;

[0067] (7) Four-time forging heating: The III-fired blank is placed in a heating furnace, heated to 1180°C and kept at 1180°C for 4 hours to obtain a four-time heated blank;

[0068] (8) IV Fire: The fourth-heated blank is stretched along the axial direction of the fourth-heated blank to forge the pump head body blank forging.

[0069] (9) Heat treatment: The pump head body blank forging is heated to 1040°C and kept at 1040°C for 20 hours, then quickly air-cooled to room temperature. The temperature is then increased to 550°C at a rate of 40°C / h and kept at this temperature for 18 hours, then quickly air-cooled to room temperature to obtain the finished product.

[0070]

[0071] The described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Claims

1. A method for preparing a shale gas hydraulic end pump head body, characterized in that: The following steps are involved: (1) Primary forging heating: After the electroslag ingot is kept at 450-650°C for 2-6 hours, it is heated to 850°C at a rate of 70°C / h or less and kept at 850°C for 2-8 hours, and then heated to 1210-1230°C at a rate of 100°C / h or less and kept at 1210-1230°C for 8-12 hours to obtain a primary heated electroslag ingot; (2) I-fire forging: Place the once heated electroslag ingot on the hydraulic press for forging, lightly press the outer circle of the once heated electroslag ingot, stand the once heated electroslag ingot upright and place it on the walkway of the hydraulic press, upset it in stages along the axial direction of the once heated electroslag ingot to half of its original height, and then flatten it along its axial direction until the length ratio of thickness: width: length is 1:1.5~2:1.5~2 to obtain a billet, press the edges and corners at both ends of the billet perpendicular to the length direction of the billet into fillets with a radius of 80~100mm; then deform it transversely, make the width direction of the billet parallel to the downward pressing direction of the hydraulic press, and the length direction of the anvil of the hydraulic press is parallel to the length direction of the billet, and forge the width dimension of the deformed billet into the billet before deformation. The thickness of the billet is forged into the width of the billet before deformation, and then it is forged into a cylindrical shape with a height-to-diameter ratio of 2:1 along the axis direction of the original primary heated electroslag ingot to obtain a first-fire billet; (3) Secondary forging heating: the first-fire billet is loaded into a heating furnace, heated to 1210~1230℃, and kept at 1210~1230℃ for 12~20 hours to obtain a secondary heated billet; (4) Secondary forging: the secondary heated billet is placed vertically on the walkway of the hydraulic press, and the secondary heated billet is upset in batches along the axis direction of the secondary heated billet to half of its original height, and then it is flattened along the axis direction to a thickness: width: length ratio of 1:1.5~2:1.5~2 to obtain a prefabricated II-fired billet, press the corners of the two ends of the prefabricated II-fired billet perpendicular to the axis of the secondary heated billet into fillets with a radius of 80~100mm; then deform it transversely, make the width direction of the prefabricated II-fired billet parallel to the downward pressing direction of the hydraulic press, and make the length direction of the hydraulic press anvil parallel to the length direction of the billet, forge the width dimension of the prefabricated II-fired billet after deformation into the thickness dimension of the prefabricated II-fired billet before deformation, and forge the thickness dimension of the prefabricated II-fired billet after deformation into the width dimension of the prefabricated II-fired billet before deformation; then forge it along the axis direction of the original once heated electroslag ingot into a cylindrical shape with a height-to-diameter ratio of 2:1 to obtain a II-fired billet; (5) Three forgings Heating: Load the II-fired blank into a heating furnace, heat it to 1100~1180℃ and keep it at 1100~1180℃ for 2~5 hours to obtain a tertiary-heated blank; (6) III-fire forging: vertically place the tertiary-heated blank on the walkway of the hydraulic press, upset the tertiary-heated blank in batches along the axis direction of the tertiary-heated blank to half of its original height, and then stretch it along the axis. The length after stretching is 50~70% of the required length of the pump head body blank forging to obtain a III-fired blank; (7) Fourth-time forging heating: Load the III-fired blank into a heating furnace, heat it to 1080~1120℃ and keep it at 1080~1120℃ for 2~5 hours. hours to obtain a four-time heated billet; (8) IV-fire forging: the four-time heated billet is stretched along the axial direction of the four-time heated billet to forge a pump head body blank forging; (9) Post-forging heat treatment: the pump head body blank forging is heated to 1050℃ and kept at 1050℃ for 2-6 hours, then heated to 1030-1050℃ at a heating rate of 40-80℃ / h and kept at this temperature for 10-20 hours, then quickly air-cooled to room temperature, then heated to 550-600℃ at a heating rate of 40-80℃ / h and kept at this temperature for 18-30 hours, then quickly air-cooled to room temperature to obtain a finished product.

2. The method for preparing a shale gas hydraulic end pump head body according to claim 1, characterized in that: In the step (1), the electroslag ingot is kept at 550° C. for 2 to 6 hours.

3. The method for preparing a shale gas hydraulic end pump head body according to claim 1, characterized in that: The hydraulic press anvil comprises an anvil body, and slope surfaces are arranged on both sides of the working surface of the anvil body, wherein the slope surfaces are composed of two arcs and a tangent connecting the two arcs.

4. The method for preparing a shale gas hydraulic end pump head body according to claim 3, characterized in that: The thickness of the anvil body is 650-700 mm.

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