A water jet cutting process for making large frame castings based on wide-thick continuous casting billets

Abstract

The application belongs to the technical field of casting and machining, and particularly provides a water jet cutting process for manufacturing large frame castings based on wide-thick continuous casting billets, S1, pretreatment of the wide-thick continuous casting billets; S2, rough cutting of the rolling mill frame contour by using a high-pressure water jet; S3, monitoring and modifying the cutting route for finishing, cutting off the excess amount reserved during rough cutting, and completing the finishing of the rolling mill frame contour; S4, inspecting the finished rolling mill frame contour, repeating step S3 until the inspection is qualified if it is unqualified, and completing the manufacturing of the rolling mill frame; the application solves the problem of low cutting precision of the existing large frame structure castings with complex shapes, which easily leads to cracks, roughness, deformation on the surface of the castings, low cutting quality and cutting efficiency, and high production cost; the application realizes the precision cutting of the large frame structure castings with complex shapes, effectively avoids the deformation and cracks caused by the heat-affected zone, has high working efficiency, realizes batch production, reduces the cost, and improves the cutting precision.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of casting and machining, and particularly relates to a water jet cutting process for manufacturing large frame castings based on wide and thick continuous casting billets. BACKGROUND

[0002] Large frame structure castings, especially cast steel and alloy steel castings used in the fields of machinery, automobiles, aviation, energy, etc., usually require high dimensional accuracy and good surface quality. Traditional cutting processes, such as mechanical sawing, laser cutting and plasma cutting, often result in cracks, roughness on the surface of the castings, and even deformation, affecting the mechanical properties and appearance quality of the castings. Especially when dealing with wide and thick continuous casting billets, these traditional processes have a significant impact on production efficiency and casting quality. As an advanced cold cutting technology, high-pressure water jet cutting can effectively avoid deformation and cracks caused by heat, and has high cutting accuracy, so it is increasingly applied in the casting industry. However, there are still some difficulties in efficiently applying water jet technology to large-sized and thick cast steel blanks.

[0003] Chinese patent document with publication number CN109396325A discloses a large-scale cast steel casting net forming technology, which includes the steps of establishing a three-dimensional model of the mold sample, computer software slicing, 3D printing of the cast sample, embedding the box, pouring, lifting the castings, sawing the riser, water jet cutting other process accessories, shot blasting, and producing finished products. The high-strength casting cavity with a smooth inner surface can be obtained. The ceramic sand cavity formed by printing will not expand and deform due to high temperature. The steel liquid solidifies and cools in the casting to form a casting with high dimensional accuracy and smooth appearance. The ceramic sand cavity has a far lower refractory limit than the ceramic sand cavity, and the steel liquid contacts the surface of the casting. The castings of this document use mold castings, which have complex processing procedures, low quality, high cost, and cannot be mass-produced. The document solves the problem of sand sticking of cast steel, but only guarantees the accuracy of straight-line steel saw cutting. For complex frame structures, the document cannot guarantee the cutting quality. SUMMARY

[0004] The present application provides a water jet cutting process for manufacturing large frame castings based on wide and thick continuous casting billets, which aims to overcome the problems of low cutting accuracy of existing technologies for complex large frame structure castings, which can lead to cracks, roughness on the surface of the castings, and even deformation, affecting the mechanical properties and appearance quality of the castings, low cutting efficiency, and high production cost.

[0005] To this end, the present application provides a water jet cutting process for manufacturing large frame castings based on wide and thick continuous casting billets, which includes the following steps:

[0006] S1, pretreatment of the wide and thick continuous casting billet;

[0007] S2, rough cutting of the mill housing profile of the pretreated wide-thick continuous casting billet is performed using a high-pressure water cutter;

[0008] S3, the rough cutting process of the mill housing profile is monitored in real time, the cutting route of the high-pressure water cutter is corrected and finished, the excess amount reserved during rough cutting is removed, and the finishing of the mill housing profile is completed;

[0009] S4, the finished mill housing profile is inspected, when the inspection is qualified, the cutting is completed, and when the inspection is unqualified, the step S3 is repeated until the inspection is qualified, and the cutting is completed.

[0010] Preferably, the pretreatment includes mechanical brushing, ultrasonic cleaning, polishing treatment or polishing treatment.

[0011] Preferably, in the step S2, the rough cutting of the mill housing profile is performed by first machining holes in the four corners of the pretreated wide-thick continuous casting billet, and then rough cutting according to the three-dimensional model.

[0012] Preferably, in the rough cutting, two high-pressure water cutters are used for alternate cutting, wherein the first high-pressure water cutter performs cutting marking, and the second high-pressure water cutter performs complete cutting.

[0013] Preferably, when the first high-pressure water cutter performs cutting marking, the preset water flow pressure only needs to achieve a cutting depth of more than half the thickness of the wide-thick continuous casting billet.

[0014] Preferably, a pressure sensor is connected to each of the two high-pressure water cutters.

[0015] Preferably, the cutting adopts front-mixed abrasive water jet cutting.

[0016] Preferably, in the front-mixed abrasive water jet cutting, the abrasive is aluminum oxide with a particle size range of 120-200 mesh.

[0017] Preferably, the cutting adopts cutting tool cutting, the cutting tool is installed on a workbench base, a water tank is arranged below the workbench base, the workbench base is hollow, and when cutting, the water carries the cutting chips into the water tank through the hollow workbench base.

[0018] Preferably, a magnetic coil is arranged in the water tank.

[0019] The beneficial effects of the present application are:

[0020] 1. The water jet cutting process for manufacturing large frame castings based on wide and thick continuous casting billets according to the present application comprises the following steps: S1, pretreatment of the wide and thick continuous casting billets; S2, rough cutting of the mill stand contour of the pretreated wide and thick continuous casting billets using high-pressure water jets; S3, real-time monitoring of the rough cutting process of the mill stand contour and correction and finishing of the cutting path of the high-pressure water jets to cut off the excess amount reserved during rough cutting and complete the finishing of the mill stand contour; S4, inspection of the finished mill stand contour, and when the inspection is qualified, the cutting is completed; when the inspection is unqualified, the step S3 is repeated until the inspection is qualified, and the mill stand is manufactured. Compared with cutting after mold casting, the present application cuts the mill stand from the wide and thick continuous casting billets to realize the manufacture of the mill stand, and the production process is simple, the work efficiency is high, batch production can be realized, and the cost is reduced; the cutting path of the high-pressure water jet is corrected and finished to optimize the cutting path and realize accurate cutting of complex frame structure castings. By using high-pressure water jet cutting, deformation and cracks caused by heat affected zone can be effectively avoided, and the cutting precision is high.

[0021] 2. The water jet cutting process for manufacturing large frame castings based on wide and thick continuous casting billets according to the present application improves the smoothness of the surface of the casting billet by adopting the pretreatment methods of mechanical brushing, ultrasonic cleaning, polishing treatment or polishing treatment.

[0022] 3. The water jet cutting process for manufacturing large frame castings based on wide and thick continuous casting billets according to the present application adopts two high-pressure water jets for alternate cutting during rough cutting, wherein the first high-pressure water jet performs cutting marking, and the second high-pressure water jet performs complete cutting. Two-stage cutting is adopted to ensure the accuracy of water jet cutting and avoid the phenomenon of incomplete cutting of the wide and thick continuous casting billets in single cutting.

[0023] 4. The water jet cutting process for manufacturing large frame castings based on wide and thick continuous casting billets according to the present application adopts front-mixed abrasive water jet cutting, and the abrasive in the front-mixed abrasive water jet cutting is aluminum oxide with a particle size range of 120-200 mesh. The present application realizes fine cutting of the wide and thick continuous casting billets, can cut out complex frame structures, meets the demand of high-precision machining, and has high abrasive utilization rate and low equipment maintenance cost. BRIEF DESCRIPTION OF DRAWINGS

[0024] The present application will be further described in detail below with reference to the accompanying drawings.

[0025] Figure 1 is a schematic diagram of the mill stand cutting and machining process. DETAILED DESCRIPTION

[0026] The principles and features of the present application are described below in conjunction with the accompanying drawings, which are presented only for the purpose of explanation and are not intended to limit the scope of the present application. If specific conditions are not specified in the examples, they are carried out under conventional conditions or according to the manufacturer's recommendations.

[0027] Embodiment 1:

[0028] A water jet cutting process for manufacturing large frame castings based on wide-thick continuous casting billets, comprising the following steps:

[0029] S1, pretreating the wide-thick continuous casting billet;

[0030] S2, using a high-pressure water jet to perform rough cutting of the mill stand contour on the pretreated wide-thick continuous casting billet;

[0031] S3, real-time monitoring of the rough cutting process of the mill stand contour and performing correction and finishing of the cutting path of the high-pressure water jet to remove the excess amount reserved during rough cutting, thereby completing the finishing of the mill stand contour;

[0032] S4, inspecting the finished mill stand contour, and when the inspection is qualified, the cutting is completed; when the inspection is unqualified, repeating step S3 until the inspection is qualified, and the cutting is completed.

[0033] The present application cuts the mill stand from the wide-thick continuous casting billet using a high-pressure water jet to achieve the manufacture of the mill stand. Compared with post-casting cutting, the production process is simple, the work efficiency is high, batch production can be realized, and the cost is reduced. By correcting and finishing the cutting path of the high-pressure water jet, the cutting path is optimized, and accurate cutting of complex frame structure castings is realized. By using high-pressure water jet cutting, deformation and cracks caused by heat affected zone can be effectively avoided, and high cutting accuracy can be achieved.

[0034] Specifically, since high-pressure water jet cutting is a cold cutting process, no heat affected zone is generated during the cutting process, avoiding material deformation and cracks that may occur in traditional cutting processes. High-pressure water jet cutting can achieve high cutting accuracy, especially suitable for processing complex frame structures and large casting blanks. High-pressure water jet cutting has high precision, reducing the need for subsequent processing (such as grinding and polishing), thereby saving production costs and time. This process can be applied to castings of various materials and different sizes, especially in the machining of large frame structure castings.

[0035] Embodiment 2:

[0036] On the basis of embodiment 1, the pretreatment includes mechanical brushing, ultrasonic cleaning, polishing or polishing.

[0037] Specifically, the smoothness of the surface of the casting blank is improved by using a pretreatment method of mechanical brushing, ultrasonic cleaning, polishing treatment or polishing treatment. Before high-pressure water jet cutting, the surface of the wide and thick continuous casting blank is first cleaned, and methods such as mechanical brushing and ultrasonic cleaning can be used to remove the oxide layer, impurities and oil stains. If the surface of the casting blank is rough, polishing or polishing treatment can be used to make the surface smoother to improve the precision of water jet cutting. The wide and thick continuous casting blank has a thickness of 400mm, a length of 3800mm and a width of 2500mm. When cutting and machining a large frame structure using a wide and thick continuous casting blank of this size, the actual operation can be performed according to the needs of the specific size of the wide and thick continuous casting blank to meet the cutting and machining of the large frame structure.

[0038] Example 3:

[0039] On the basis of example 2, in the rough cutting of the rolling mill housing profile in step S2, first, the four corners of the pretreated wide and thick continuous casting blank are processed with holes, and then rough cutting is performed according to the three-dimensional model.

[0040] Specifically, first, the four corners of the continuous casting blank are processed with holes, which not only avoids thermal deformation during material processing, but also ensures that the hole machining tool has high precision.

[0041] Preferably, in the rough cutting, a monitoring camera and an infrared sensor are used at the front end of the cutting area.

[0042] Specifically, by using a monitoring camera at the front end of the cutting area, when the monitoring camera at the front end of the cutting area detects that the wide and thick continuous casting blank enters the mileage, the cutter starts to move parallel to the wide and thick continuous casting blank. After the infrared sensor detects the front end of the wide and thick continuous casting blank, the water jet is aligned with the preset starting point; which facilitates accurate monitoring of the arrival of the wide and thick continuous casting blank and improves the cutting precision.

[0043] Example 4:

[0044] On the basis of example 3, in the rough cutting, two high-pressure water jets are used to cut alternately, wherein the first high-pressure water jet cuts a line, and the second high-pressure water jet cuts completely.

[0045] Specifically, by using two high-pressure water jets to cut alternately, the wear of the cutter by high-pressure water flow is reduced and the processing efficiency is ensured.

[0046] Preferably, when the first high-pressure water jet cuts a line, the preset water flow pressure only needs to achieve a cutting depth of more than half the thickness of the wide and thick continuous casting blank.

[0047] Specifically, the first high-pressure water cutter performs cutting and marking, and the preset water flow pressure only needs to achieve a cutting depth of more than half of the thickness of the casting. After the first high-pressure water cutter cuts for 50-100 cm, the second high-pressure water cutter starts to move to completely cut the wide and thick continuous casting billet. The two-stage cutting ensures the accuracy of the water cutter cutting and avoids the phenomenon of incomplete cutting of the wide and thick continuous casting billet in single cutting.

[0048] Preferably, the rough cutting comprises the following steps: first, rough cutting and marking the outer contour of the rolling mill housing, according to the cutting; then, rough cutting the inner contour of the rolling mill housing; and finally, rough cutting the thickness direction contour of the rolling mill housing to complete the rough cutting of the rolling mill housing contour.

[0049] Specifically, after the rough cutting of the outer contour of the rolling mill housing is completed, the high-pressure water cutter moves to the preset starting point of the inner contour processing, and starts to perform the rough cutting of the inner contour of the rolling mill housing. Two high-pressure water cutters are used to cut the excess part in the middle of the rolling mill housing in turn to process the inner contour of the rolling mill housing. After the rough cutting of the inner contour of the rolling mill housing is completed, the high-pressure cutter is moved to the third preset starting point, and the cutter is adjusted to keep it in a horizontal state, and the processing of the thickness direction contour of the rolling mill housing is started to cut out the approximate contour. After the approximate contour of the rolling mill housing is cut out, the continuous casting billet left by the above cutting process is removed by the mechanical arm. The operation is simple.

[0050] Example 5:

[0051] On the basis of example 4, a pressure sensor is arranged on each of the two high-pressure water cutters.

[0052] Specifically, the working pressure of the high-pressure water cutter is monitored by installing a pressure sensor on the high-pressure water cutter, and the water pressure regulator installed on the high-pressure water pump is controlled by the system (the system is an existing control system, and the control system is used to control the water pressure of the water pressure regulator installed on the high-pressure water pump. The specific selection is according to the actual needs) to realize the automatic control of the working pressure of the water cutter, so that the water pressure is kept within a certain range to ensure the effective cutting of the high-pressure water cutter.

[0053] Example 6:

[0054] On the basis of example 5, the cutting adopts front mixed abrasive water jet cutting.

[0055] Specifically, the front mixed abrasive water jet cutting has high safety, good environmental protection, strong cutting ability and high working efficiency.

[0056] Preferably, in the front mixed abrasive water jet cutting, the abrasive is aluminum oxide with a particle size range of 120-200 mesh.

[0057] Specifically, the abrasive is selected as alumina with a particle size range of 120-200 meshes, so as to realize fine cutting of the wide and thick continuous casting billet, cut a complex frame structure, meet the demand of high-precision machining, and the abrasive utilization rate of the front mixed abrasive cutting system is high, and the equipment maintenance cost is low.

[0058] Embodiment 7:

[0059] On the basis of embodiment 6, the cutting route of the high-pressure water cutter is corrected and refined, and a control software is used to correct and refine the cutting route of the high-pressure water cutter, wherein the control software includes FlowNest, NEWCAM and ALMA (Code A) ACT / CUT.

[0060] Specifically, the control software is used to optimize the cutting route of the high-pressure water cutter, so as to meet the cutting of the complex frame structure and improve the cutting efficiency and cutting precision.

[0061] Preferably, during cutting, a monitoring camera is installed equidistantly in the working area to dynamically monitor the cutting of the high-pressure water cutter.

[0062] Specifically, the monitoring camera improves the detection of the machining precision.

[0063] Preferably, the monitoring camera is a laser scanning camera.

[0064] Specifically, the fine machining is started, the profile of the wide and thick continuous casting billet is monitored in real time by laser scanning, and is transmitted to the control system to correct and refine the cutting route of the high-pressure water cutter, so as to cut layer by layer and cut off the allowance reserved during rough machining. After the profile of the rolling mill frame is qualified by laser scanning, the system controls the high-pressure cutter to move to the preset end point, and after the sensor detects the high-pressure water cutter, it represents that the cutting machining is completed; if the inspection is unqualified, the fine machining is re-performed. The cutting surface is checked by image recognition technology to ensure that there is no obvious crack, burn or other surface defects. If problems are found, they can be corrected by further trimming or cleaning.

[0065] Embodiment 8:

[0066] On the basis of embodiment 7, the cutting is performed by a cutting tool, the cutting tool is installed on a workbench base, a water tank is arranged below the workbench base, the workbench base is hollow, and during cutting, the water carrying the cutting chips enters the water tank through the hollow workbench base.

[0067] Specifically, the structure is simple and convenient for removing the cutting chips.

[0068] Preferably, a magnetic coil is arranged in the water tank.

[0069] Specifically, by setting the water tank connected with the magnetic coil, the metal chips are adsorbed after being electrified, avoiding the loss of the chips, facilitating the recycling of the chips and saving materials.

[0070] Preferably, the water outlet of the water tank is provided with a filter screen.

[0071] Specifically, the filter screen installed at the water outlet can filter the abrasives in the water, thereby realizing the recycling of the water and reducing the waste of water and abrasives.

[0072] Preferably, after the overall cutting of the rolling mill housing profile is completed, the cutting surface is washed with high-pressure water flow of about 50-100 MPa.

[0073] Specifically, after the overall cutting is completed, the cutting surface is washed with high-pressure water flow of about 50-100 MPa to remove the metal particles, residual cutting fluid and impurities attached to the surface, which not only avoids the damage to the processed products caused by the water flow pressure, but also has good economy and practicability.

[0074] Preferably, as shown in Figure 1 The cutting processing of the rolling mill housing includes the following steps:

[0075] S1.1, rough cutting and marking of the outer contour of the rolling mill housing;

[0076] S1.2, rough cutting and cutting of the outer contour of the rolling mill housing;

[0077] S1.3, rough cutting and marking of the inner contour of the rolling mill housing;

[0078] S1.4, rough cutting and cutting of the inner contour of the rolling mill housing;

[0079] S1.5, rough cutting and marking of the thickness direction contour of the rolling mill housing;

[0080] S1.6, rough cutting and cutting of the thickness direction contour of the rolling mill housing;

[0081] S1.7, removing the excess material after cutting;

[0082] S1.8, laser scanning to monitor the cutting process;

[0083] S1.9, according to the scanning results and the model, finishing the cutting path planning;

[0084] S1.10, finishing cutting of the outer contour of the rolling mill housing;

[0085] S1.11, finishing cutting of the inner contour of the rolling mill housing;

[0086] S1.12, finishing cutting of the thickness direction contour of the rolling mill housing;

[0087] S1.13, laser scanning verifies whether the profile of the mill housing after cutting is qualified, if qualified, the cutter returns to the starting point; if not qualified, the above steps S1.8-S1.13 are repeated until the test result is qualified.

[0088] Specifically, the mill housing is manufactured with high cutting precision, is suitable for processing complex frame structures and large casting blanks, reduces the need for subsequent processing (such as grinding and polishing), thereby saving production cost and time. It can be applied to castings of various materials and different sizes, and is particularly outstanding in the processing of large frame structure castings.

[0089] In the description of the present application, it should be understood that if the terms "below", "inner" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the terms describing the positional relationship in the drawings are only used for exemplary description, and cannot be understood as a limitation on the present application.

[0090] The above examples are only illustrative of the present application and do not constitute a limitation on the scope of protection of the present application, any design identical or similar to the present application falls within the scope of protection of the present application.

Claims

1. A waterjet cutting process for fabricating large frame castings from thick continuous casting billets, characterized in that: Includes the following steps: S1. Pretreatment of wide and thick continuous casting billets; S2. Use a high-pressure water jet to roughly cut the outline of the mill stand of the pretreated wide and thick continuous casting billet; during the rough cutting, two high-pressure water jets are used to cut alternately, wherein the first high-pressure water jet is used to cut and scribing, and the second high-pressure water jet is used to completely cut off; when the first high-pressure water jet is used to cut and scribing, its preset water flow pressure only needs to achieve a cutting depth of more than half of the thickness of the wide and thick continuous casting billet. S3. Real-time monitoring of the rough cutting process of the mill stand outline, and correction and finishing of the cutting path of the high-pressure water jet, removing the allowance reserved during rough cutting, and completing the finishing of the mill stand outline; specifically: start finishing, use laser scanning to monitor the outline of the wide and thick continuous casting billet in real time, and transmit it to the control system to correct and finish the cutting path of the high-pressure water jet, cut layer by layer, and remove the allowance reserved during rough cutting; S4. Inspect the outline of the finished mill stand. If the inspection is qualified, the cutting is completed. If the inspection is unqualified, repeat step S3 until the inspection is qualified and the mill stand is completed. Specifically, after the outline of the mill stand is qualified by laser scanning, the system controls the high-pressure cutter to move to the preset end point. After the sensor detects the high-pressure water jet, the cutting process is completed. If the inspection is unqualified, the finishing process is repeated.

2. The waterjet cutting process for producing large frame castings based on thick continuous casting billets as described in claim 1, characterized in that: The pretreatment includes mechanical brushing, ultrasonic cleaning, grinding, or polishing.

3. The waterjet cutting process for producing large frame castings based on thick continuous casting billets as described in claim 1, characterized in that: In step S2, when rough cutting the outline of the rolling mill stand, holes are first machined at the four corners of the pre-treated wide and thick continuous casting billet, and then rough cutting is performed according to the three-dimensional model.

4. The waterjet cutting process for producing large frame castings based on thick continuous casting billets as described in claim 1, characterized in that: Both high-pressure water jets are equipped with pressure sensors.

5. The waterjet cutting process for producing large frame castings based on thick continuous casting billets as described in claim 1, characterized in that: The cutting process employs pre-mixed abrasive waterjet cutting.

6. The waterjet cutting process for producing large frame castings based on thick continuous casting billets as described in claim 5, characterized in that: In the premixed abrasive waterjet cutting, the abrasive is aluminum oxide with a particle size range of 120-200 mesh.

7. The waterjet cutting process for producing large frame castings based on thick continuous casting billets as described in claim 1, characterized in that: The cutting is performed using a cutting tool mounted on a workbench base. A water tank is installed below the workbench base, which is perforated. During cutting, water carries the cutting chips through the perforated workbench base into the water tank.

8. The waterjet cutting process for producing large frame castings based on thick continuous casting billets as described in claim 7, characterized in that: A magnetic coil is installed inside the water tank.

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