Welding process for forged steel part production

Abstract

The invention provides a welding technology for forged steel part production. The welding technology comprises the following steps that S1, welding preparation is conducted; s2, welding; and S3, post-welding treatment is conducted. According to the welding process for forged steel part production, the welding quality is stable, preheating, multi-layer and multi-pass welding and other measures are adopted, generation of defects such as welding cracks and air holes can be reduced, the strength and reliability of a welded joint are improved, the welding efficiency is high, the proper welding method and welding parameters are adopted, the welding speed can be increased, the production period is shortened, and the production cost is reduced. The heat affected zone is small, the reasonable welding process and welding materials are adopted, the welding heat affected zone can be reduced, the mechanical performance of the forged steel part is improved, the service life of the forged steel part is prolonged, operation is easy, the technical requirement for operators is low, and the method is suitable for large-scale production.

Description

Technical Field

[0001] The invention relates to the technical field of forged steel production, and in particular to a welding process for producing forged steel parts. Background Art

[0002] Forged steel parts have good mechanical properties and reliability and are widely used in machinery manufacturing, aerospace, petrochemical and other fields.

[0003] Forged steel parts are objects that are molded into the required shape or appropriate compression force by plastic deformation under pressure. Each piece of forged steel parts needs to be consistent without any porosity, extra space, inclusions or other defects. Welding is required in the production process of forged steel parts. Welding is also called fusion welding. It is a manufacturing process and technology that joins metals or other thermoplastic materials such as plastics by heating, high temperature or high pressure. During the welding process, the workpiece and the solder melt to form a molten area. After the molten pool cools and solidifies, a connection between the materials is formed.

[0004] In the production process of forged steel parts, welding is an important link. The existing welding process has problems such as unstable welding quality, low welding efficiency and large heat-affected zone.

[0005] Therefore, it is necessary to provide a welding process for producing forged steel parts to solve the above technical problems. Summary of the invention

[0006] The invention provides a welding process for producing forged steel parts, which solves the problems of unstable welding quality, low welding efficiency and large heat-affected zone in the existing welding process.

[0007] In order to solve the above technical problems, the present invention provides a welding process for producing forged steel parts, comprising the following steps: S1: welding preparation; S2: welding; S3: post-weld treatment;

[0008] The welding comprises the following steps: S21: preheating, 42CrMo forged steel parts are preheated before welding, the preheating temperature is between 250℃-350℃, and the preheating can be carried out by means of oxygen-acetylene flame heating and electric heating plate; S22: welding parameter setting; for E5515-B2-V welding rod with a diameter of 4mm, the welding current at the flat welding position can be controlled at 160-180A, the vertical welding position can be appropriately reduced to 140-160A, and the overhead welding position is controlled at 130-150A; the arc voltage is controlled to be maintained between 22-26V by adjusting the output voltage of the welding machine; the welding speed is controlled at 15-20cm / min; S23: welding operation , base welding, filling welding and cap welding can be used. When performing base welding, a small diameter electrode is used for base welding, the welding current is slightly smaller, short arc welding is adopted, the angle between the electrode and the weldment is maintained at 70°-80°, and the electrode movement method can be serrated and crescent-shaped; a 4mm diameter electrode is used for filling welding, and welding is carried out according to the welding parameters and electrode movement method of base welding; when performing cap welding, the weld excess height is controlled at 2-3mm, and the width is 2-3mm wider than each side of the groove; S24: During the welding process, the interlayer temperature is maintained between 250℃-300℃, and the weld temperature is regularly measured with an infrared thermometer for control. If the interlayer temperature is too high, welding is stopped, and welding is continued after the temperature drops.

[0009] Preferably, the welding preparation includes the following steps: S11: selecting 42CrMo medium carbon alloy steel; S12: welding equipment selection: selecting an inverter DC welding machine; S13: welding material selection: selecting low-hydrogen welding materials that match the strength and chemical composition of 42CrMo, and the welding rod is dried before use, the drying temperature is 350℃-400℃, the insulation time is 1-2 hours, and then placed in a 100℃-150℃ insulation cylinder for use; S14: groove preparation: preparing the groove according to the thickness of the forged steel part and the form of the welded joint. For forged steel parts with a thickness greater than 10mm, a U-shaped or double V-shaped groove is used, the groove angle is between 60°-70°, the blunt edge thickness is 2-3mm, and the root gap is 2-4mm; the groove processing adopts milling and planing mechanical processing methods. After the processing is completed, the groove and the groove on both sides within 20-30mm are cleaned to remove impurities such as oil, rust, and scale, and the grinding and chemical cleaning methods are adopted.

[0010] Preferably, the post-weld treatment comprises the following steps: S31: after welding is completed, post-heat treatment is performed, the post-heating temperature is 300°C-350°C, the insulation time is 2-3 hours, after the insulation is completed, the weld is wrapped with asbestos cloth insulation material to slowly cool it to room temperature; S32: visual inspection of the weld; ultrasonic and radiographic inspection methods are used to detect the inside of the weld to check the internal conditions, and unqualified welds are repaired according to the inspection results; specimens are cut from the weld specimens for tensile tests, impact tests and hardness tests to test the mechanical properties.

[0011] Preferably, a preheating box is required for the preheating treatment, and the preheating box includes a treatment box; a box door is rotatably installed on the surface of the treatment box, a heating chamber is opened in the middle of the surface of the treatment box, and both sides of the outer surface of the treatment box are fixedly installed on a pushing device, the pushing device includes a hydraulic cylinder and a push plate, a rotating device is fixedly installed in the middle of the surface of the pushing device, and the rotating device includes a fixed plate, a servo motor, a supporting plate and an anti-sliding plate.

[0012] Preferably, the hydraulic cylinder is fixedly installed in the middle of one side of the outer surface of the processing box, and the push plate is fixedly connected to the end of the output shaft of the hydraulic cylinder.

[0013] Preferably, the fixing plate is fixedly installed in the middle of the push plate surface, the servo motor is fixedly installed in the middle of one side of the fixing plate, the supporting plate is fixedly connected to the output shaft end of the servo motor, and the anti-sliding block is fixedly installed on the surface of the supporting plate.

[0014] Preferably, a connecting pipe is fixedly connected to the top of the processing box, and the other end of the connecting pipe is fixedly connected to a conveying box.

[0015] Preferably, a controller is fixedly mounted on the surface of the conveying box.

[0016] Preferably, a stretching tube is fixedly connected to the rear side of the processing box.

[0017] Preferably, one end of the stretch tube is fixedly connected to a connecting sleeve.

[0018] Compared with the related art, the welding process for producing forged steel parts provided by the present invention has the following beneficial effects:

[0019] The present invention provides a welding process for producing forged steel parts. The welding quality is stable. Preheating, multi-layer and multi-pass welding and other measures are adopted to reduce the generation of defects such as welding cracks and pores, improve the strength and reliability of the welded joint, and the welding efficiency is high. The welding speed can be increased and the production cycle can be shortened by adopting a suitable welding method and welding parameters. The heat-affected zone is small. The welding heat-affected zone can be reduced by adopting a reasonable welding process and welding materials, and the mechanical properties and service life of the forged steel parts are improved. The operation is simple, the technical requirements for operators are low, and the process is suitable for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic structural diagram of a first embodiment of a welding process for producing forged steel parts provided by the present invention;

[0021] Figure 2 A schematic structural diagram of a second embodiment of a welding process for producing forged steel parts provided by the present invention;

[0022] Figure 3 for Figure 2 An enlarged schematic diagram of point A is shown;

[0023] Figure 4 for Figure 2 A schematic side view of the processing box is shown.

[0024] Numbers in the figure: 1. processing box, 2. heating chamber, 3. box door, 4. pushing device, 41. hydraulic cylinder, 42. push plate, 5. rotating device, 51. fixing plate, 52. servo motor, 53. supporting plate, 54. anti-sliding block, 6. connecting pipe, 7. conveying box, 8. controller, 9. connecting sleeve, 10. stretching tube. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the accompanying drawings and implementation modes.

[0026] First embodiment

[0027] Please refer to Figure 1 ,in, Figure 1 A structural schematic diagram of a first embodiment of a welding process for producing forged steel parts provided by the present invention. A welding process for producing forged steel parts comprises the following steps: S1: welding preparation; S2: welding; S3: post-weld treatment;

[0028] The welding comprises the following steps: S21: preheating, 42CrMo forged steel parts are preheated before welding, the preheating temperature is between 250℃-350℃, and the preheating can be carried out by means of oxygen-acetylene flame heating and electric heating plate; S22: welding parameter setting; for E5515-B2-V welding rod with a diameter of 4mm, the welding current at the flat welding position can be controlled at 160-180A, the vertical welding position can be appropriately reduced to 140-160A, and the overhead welding position is controlled at 130-150A; the arc voltage is controlled to be maintained between 22-26V by adjusting the output voltage of the welding machine; the welding speed is controlled at 15-20cm / min; S23: welding operation , base welding, filling welding and cap welding can be used. When performing base welding, a small diameter electrode is used for base welding, the welding current is slightly smaller, short arc welding is adopted, the angle between the electrode and the weldment is maintained at 70°-80°, and the electrode movement method can be serrated and crescent-shaped; a 4mm diameter electrode is used for filling welding, and welding is carried out according to the welding parameters and electrode movement method of base welding; when performing cap welding, the weld excess height is controlled at 2-3mm, and the width is 2-3mm wider than each side of the groove; S24: During the welding process, the interlayer temperature is maintained between 250℃-300℃, and the weld temperature is regularly measured with an infrared thermometer for control. If the interlayer temperature is too high, welding is stopped, and welding is continued after the temperature drops.

[0029] Preferably, the welding preparation includes the following steps: S11: selecting 42CrMo medium carbon alloy steel; S12: welding equipment selection: selecting an inverter DC welding machine; S13: welding material selection: selecting low-hydrogen welding materials that match the strength and chemical composition of 42CrMo, and the welding rod is dried before use, the drying temperature is 350℃-400℃, the insulation time is 1-2 hours, and then placed in a 100℃-150℃ insulation cylinder for use; S14: groove preparation: preparing the groove according to the thickness of the forged steel part and the form of the welded joint. For forged steel parts with a thickness greater than 10mm, a U-shaped or double V-shaped groove is used, the groove angle is between 60°-70°, the blunt edge thickness is 2-3mm, and the root gap is 2-4mm; the groove processing adopts milling and planing mechanical processing methods. After the processing is completed, the groove and the groove on both sides within 20-30mm are cleaned to remove impurities such as oil, rust, and scale, and the grinding and chemical cleaning methods are adopted.

[0030] Preferably, the post-weld treatment comprises the following steps: S31: after welding is completed, post-heat treatment is performed, the post-heating temperature is 300°C-350°C, the insulation time is 2-3 hours, after the insulation is completed, the weld is wrapped with asbestos cloth insulation material to slowly cool it to room temperature; S32: visual inspection of the weld; ultrasonic and radiographic inspection methods are used to detect the inside of the weld to check the internal conditions, and unqualified welds are repaired according to the inspection results; specimens are cut from the weld specimens for tensile tests, impact tests and hardness tests to test the mechanical properties.

[0031] The working principle of a welding process for producing forged steel parts provided by the present invention is as follows:

[0032] When working, first select 42CrMo medium carbon alloy steel; select inverter DC welding machine; select low hydrogen welding materials that match the strength and chemical composition of 42CrMo, and dry the welding rod before use. The drying temperature is 350℃-400℃, and the insulation time is 1-2 hours. Then put it in a 100℃-150℃ insulation cylinder for use; prepare the groove according to the thickness of the forged steel parts and the form of the welding joint. For forged steel parts with a thickness greater than 10mm, use U-shaped or double V-shaped grooves, the groove angle is between 60°-70°, the blunt edge thickness is 2-3mm, and the root gap is 2-4mm; the groove processing adopts milling and planing mechanical processing methods. After the processing is completed, the groove and the 20-30mm range on both sides are cleaned to remove impurities such as oil, rust, and scale, and the method of grinding and chemical cleaning is adopted.

[0033] 42CrMo forged steel parts are preheated before welding, and the preheating temperature is between 250℃-350℃. Oxy-acetylene flame heating and electric heating sheet can be used for preheating. For E5515-B2-V welding rod with a diameter of 4mm, the welding current in the flat welding position can be controlled at 160-180A, the vertical welding position can be appropriately reduced to 140-160A, and the overhead welding position is controlled at 130-150A. The arc voltage is controlled to be between 22-26V by adjusting the output voltage of the welding machine; the welding speed is controlled at 15-20cm / min; the base welding, filling welding and cap welding can be used. Method: When performing base welding, use a small diameter electrode for base welding, the welding current is slightly smaller, short arc welding is adopted, the angle between the electrode and the weldment is maintained at 70°-80°, and the electrode movement method can be serrated and crescent-shaped; use a 4mm diameter electrode for filling welding, and weld according to the welding parameters and electrode movement method of base welding; when performing cover welding, the weld excess height is controlled at 2-3mm, and the width is 2-3mm wider than each side of the groove; during the welding process, the interlayer temperature is maintained between 250℃-300℃, and the weld temperature is regularly measured with an infrared thermometer for control. If the interlayer temperature is too high, welding is stopped, and welding is continued after the temperature drops.

[0034] After welding is completed, post-heat treatment is carried out at a temperature of 300℃-350℃ and a holding time of 2-3 hours. After the holding is completed, the weld is wrapped with asbestos cloth insulation material to allow it to slowly cool to room temperature; the weld is visually inspected, and the inside of the weld is inspected using ultrasonic and radiographic methods to check the internal conditions. Unqualified welds are repaired based on the test results; specimens are cut from the welded specimens for tensile tests, impact tests, and hardness tests to test the mechanical properties.

[0035] Compared with the related art, the welding process for producing forged steel parts provided by the present invention has the following beneficial effects:

[0036] The present invention provides a welding process for producing forged steel parts. The welding quality is stable. Preheating, multi-layer and multi-pass welding and other measures are adopted to reduce the generation of defects such as welding cracks and pores, improve the strength and reliability of the welded joint, and the welding efficiency is high. The welding speed can be increased and the production cycle can be shortened by adopting a suitable welding method and welding parameters. The heat-affected zone is small. The welding heat-affected zone can be reduced by adopting a reasonable welding process and welding materials, and the mechanical properties and service life of the forged steel parts are improved. The operation is simple, the technical requirements for operators are low, and the process is suitable for large-scale production.

[0037] Second embodiment

[0038] Please refer to Figure 2 , Figure 3 and Figure 4 Based on the welding process for producing forged steel parts provided in the first embodiment of the present application, the second embodiment of the present application proposes another welding process for producing forged steel parts. The second embodiment is only a preferred embodiment of the first embodiment, and the implementation of the second embodiment will not affect the independent implementation of the first embodiment.

[0039] Specifically, the difference of a welding process for producing forged steel parts provided in the second embodiment of the present application is that, in a welding process for producing forged steel parts, a preheating box is required for the preheating treatment, and the preheating box includes a processing box 1; a box door 3 is rotatably installed on the surface of the processing box 1, and a heating chamber 2 is opened in the middle of the surface of the processing box 1, and both sides of the outer surface of the processing box 1 are fixedly installed on a pushing device 4, and the pushing device 4 includes a hydraulic cylinder 41 and a push plate 42, and a rotating device 5 is fixedly installed in the middle of the surface of the pushing device 4, and the rotating device 5 includes a fixed plate 51, a servo motor 52, a supporting plate 53 and an anti-sliding plate 54.

[0040] The hydraulic cylinder 41 is fixedly installed in the middle of one side of the outer surface of the processing box 1 , and the push plate 42 is fixedly connected to the end of the output shaft of the hydraulic cylinder 41 .

[0041] The fixing plate 51 is fixedly installed in the middle of the surface of the push plate 42, the servo motor 52 is fixedly installed in the middle of one side of the fixing plate 51, the supporting plate 53 is fixedly connected to the output shaft end of the servo motor 52, and the anti-sliding block 54 is fixedly installed on the surface of the supporting plate 53.

[0042] A connecting pipe 6 is fixedly connected to the top of the processing box 1 , and a conveying box 7 is fixedly connected to the other end of the connecting pipe 6 .

[0043] A controller 8 is fixedly mounted on the surface of the conveying box 7 .

[0044] A stretching tube 10 is fixedly connected to the rear side of the processing box 1 .

[0045] One end of the stretch tube 10 is fixedly connected to a connecting sleeve 9 .

[0046] The working principle of a welding process for producing forged steel parts provided by the present invention is as follows:

[0047] During operation, firstly, the two hydraulic cylinders 41 are controlled by an external power supply to move and push the two holding plates 53 to hold the forged steel parts inside the heating chamber 2. The output shaft of the servo motor 52 rotates to drive the forged steel parts to rotate, so that the bottom side of the forged steel parts faces upward for heating.

[0048] Compared with the related art, the welding process for producing forged steel parts provided by the present invention has the following beneficial effects:

[0049] The present invention provides a welding process for the production of forged steel parts. An external power supply is used to control the movement of two hydraulic cylinders 41 to push two holding plates 53 to hold the forged steel parts inside the heating chamber 2. The output shaft of the servo motor 52 rotates to drive the forged steel parts to rotate, and the heating surface of the forged steel parts is adjusted. The device has a simple structure and strong practicality. The operator can adjust the heating surface of the forged steel parts according to the heating requirements of the forged steel parts, avoiding the situation where the heating effect of the bottom of the forged steel parts attached to the side of the heating chamber 2 is not as good as that of other surfaces, maintaining the uniformity of surface preheating when the forged steel parts are preheated, and improving the practicality of the device.

[0050] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A welding process for producing forged steel parts, characterized in that: The following steps are involved: S1: welding preparation; S2: welding; S3: post-weld treatment; The welding comprises the following steps: S21: preheating, 42CrMo forged steel parts are preheated before welding, the preheating temperature is between 250℃-350℃, and the preheating can be carried out by means of oxygen-acetylene flame heating and electric heating plate; S22: welding parameter setting; for E5515-B2-V welding rod with a diameter of 4mm, the welding current at the flat welding position can be controlled at 160-180A, the vertical welding position can be appropriately reduced to 140-160A, and the overhead welding position is controlled at 130-150A; the arc voltage is controlled to be maintained between 22-26V by adjusting the output voltage of the welding machine; the welding speed is controlled at 15-20cm / min; S23: welding operation , base welding, filling welding and cap welding can be used. When performing base welding, a small diameter electrode is used for base welding, the welding current is slightly smaller, short arc welding is adopted, the angle between the electrode and the weldment is maintained at 70°-80°, and the electrode movement method can be serrated and crescent-shaped; a 4mm diameter electrode is used for filling welding, and welding is carried out according to the welding parameters and electrode movement method of base welding; when performing cap welding, the weld excess height is controlled at 2-3mm, and the width is 2-3mm wider than each side of the groove; S24: During the welding process, the interlayer temperature is maintained between 250℃-300℃, and the weld temperature is regularly measured with an infrared thermometer for control. If the interlayer temperature is too high, welding is stopped, and welding is continued after the temperature drops.

2. A welding process for producing forged steel parts according to claim 1, characterized in that: The welding preparation The method comprises the following steps: S11: selecting 42CrMo medium carbon alloy steel; S12: selecting welding equipment: selecting an inverter DC welding machine; S13: selecting welding materials: selecting low hydrogen welding materials matching the strength and chemical composition of 42CrMo, drying the welding rod before use, the drying temperature being 350-400°C, the insulation time being 1-2 hours, and then placing the welding rod in an insulation cylinder at 100-150°C for use; S14: preparing grooves: preparing grooves according to the thickness of the forged steel piece and the form of the welding joint, for forged steel pieces with a thickness greater than 10mm, using U-shaped or double V-shaped grooves, the groove angle being between 60° and 70°, the blunt edge thickness being 2-3mm, and the root gap being 2-4mm; the groove processing adopts milling and planing mechanical processing methods, after the processing is completed, cleaning the groove and the groove within 20-30mm on both sides thereof, removing impurities such as oil, rust, scale, etc., and adopting grinding and chemical cleaning methods.

3. A welding process for producing forged steel parts according to claim 1, characterized in that: The post-weld treatment The method comprises the following steps: S31: after welding is completed, post-heat treatment is performed, the post-heating temperature is 300°C-350°C, the insulation time is 2-3 hours, after the insulation is completed, the weld is wrapped with asbestos cloth insulation material to slowly cool it to room temperature; S32: the weld is visually inspected; the inside of the weld is inspected by ultrasonic flaw detection and radiographic flaw detection methods to check the internal conditions, and unqualified welds are repaired according to the inspection results; samples are cut from the welded specimens to perform tensile tests, impact tests and hardness tests for mechanical property tests.

4. A welding process for producing forged steel parts according to claim 1, characterized in that: A preheating box is required for the preheating treatment, and the preheating box includes a treatment box; a box door is rotatably installed on the surface of the treatment box, a heating chamber is opened in the middle of the surface of the treatment box, and both sides of the outer surface of the treatment box are fixedly installed on a pushing device, the pushing device includes a hydraulic cylinder and a pushing plate, and a rotating device is fixedly installed in the middle of the surface of the pushing device, and the rotating device includes a fixed plate, a servo motor, a supporting plate and an anti-sliding block.

5. A welding process for producing forged steel parts according to claim 4, characterized in that: The hydraulic cylinder is fixedly installed in the middle of one side of the outer surface of the processing box, and the push plate is fixedly connected to the end of the output shaft of the hydraulic cylinder.

6. A welding process for producing forged steel parts according to claim 4, characterized in that: The fixing plate is fixedly installed in the middle of the push plate surface, the servo motor is fixedly installed in the middle of one side of the fixing plate, the supporting plate is fixedly connected to the output shaft end of the servo motor, and the anti-sliding block is fixedly installed on the surface of the supporting plate.

7. A welding process for producing forged steel parts according to claim 4, characterized in that: The top of the processing box is fixedly connected with a connecting pipe, and the other end of the connecting pipe is fixedly connected with a conveying box.

8. A welding process for producing forged steel parts according to claim 7, characterized in that: A controller is fixedly mounted on the surface of the conveying box.

9. A welding process for producing forged steel parts according to claim 4, characterized in that: A stretching tube is fixedly connected to the rear side of the processing box.

10. A welding process for producing forged steel parts according to claim 9, characterized in that: One end of the stretch tube is fixedly connected with a connecting sleeve.

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