Processing technology of flow guide hole type arc-shaped crystallizer copper pipe

Abstract

The invention discloses a processing technology of a flow guide hole type arc-shaped crystallizer copper pipe, and relates to the technical field of crystallizer copper pipe processing, which comprises the following steps of: preparing a straight square blank of the copper pipe: drawing the copper pipe blank on a horizontal oil press through a straight core rod and a square concave die to form the straight square blank of the copper pipe; processing a flow guide hole: pre-drilling a through hole of which the diameter is 12% larger than that of the flow guide hole in the drawing on the straight square blank; filling the flow guide hole: firstly plugging one end of the processed flow guide hole by using a copper plug, and pouring a filler from the other end to fill the flow guide hole; extruding and forming the copper pipe, namely penetrating an arc-shaped core rod into the straight square blank, and enabling the copper pipe to penetrate through a concave die which is consistent with the copper pipe in appearance section size under the driving of a horizontal oil press; cleaning and repairing the flow guide hole: cleaning the filler in the flow guide hole and then repairing the flow guide hole; sawing heads and milling: trimming the total length of the copper pipe, sawing the heads at the two ends of the copper pipe of the crystallizer, and processing a clamping plate groove; the machining quality of the flow guide hole of the arc-shaped crystallizer copper pipe can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of crystallizer copper tube processing, in particular to a processing technology of a guide hole type arc-shaped crystallizer copper tube. Background Art

[0002] The crystallizer copper tube is the core component of the steel continuous casting machine. With the continuous development of steel continuous casting technology, in order to improve steel production efficiency and steel quality, in recent years, the continuous casting crystallizer equipment and spare parts market has added many improved types of crystallizer copper tube structures, such as outer surface finishing copper tubes, grooved copper tubes, and guide hole copper tubes.

[0003] The cooling of the guide hole type crystallizer copper tube is through circular holes arranged at a certain distance along the longitudinal direction (length direction) of the crystallizer copper tube wall. During the working process, when the crystallizer cooling water with a pressure of about 1MPa flows through the guide holes on the crystallizer copper tube wall, the entire circumference of the hole is responsible for heat transfer, which is more efficient than the cooling of the ordinary tube type crystallizer copper tube. Moreover, since the pressure of the cooling water in the hole on the circumference in all directions is uniform, the pressure in all directions in the hole offsets each other, which is equivalent to the pressure of the crystallizer cooling water on the crystallizer copper tube wall in the direction of the copper tube inner cavity being zero. The other types of crystallizer copper tubes often have a unidirectional force on the copper tube wall due to the crystallizer cooling water pressure relative to the copper tube wall, which leads to the tendency of the copper tube wall to deform toward the inner cavity of the copper tube, thereby causing the deformation error of the taper of the inner cavity of the copper tube. The guide hole type copper tube can eliminate the deformation of the copper tube caused by the cooling water pressure during the working process of the copper tube, and better maintain the accuracy of the crystallizer copper tube during the working process.

[0004] In the prior art, when processing the guide holes of the crystallizer copper tube, there are problems of poor processing accuracy and large roundness error of the guide holes. In order to reduce the deformation of the guide holes in the subsequent stretching forming process of the copper tube in the prior art, although the guide holes are filled before stretching, when filling the guide holes in the prior art, there are problems of improving the shrinkage and flattening effect of the guide holes or the subsequent filling is difficult to clean. Summary of the invention

[0005] In view of the above technical problems, the present invention proposes a processing technology for a guide hole type arc-shaped crystallizer copper tube, comprising the following steps: S1. Preparation of a straight square blank of a copper tube: Drawing a copper tube blank with a half-bottom structure into a straight square blank of a copper tube on a horizontal hydraulic press through a straight core rod and a square die.

[0006] S2. Processing of guide holes: When processing guide holes: pre-drill a through hole 12% larger than the diameter design size of the hole in the drawing on the rectangular blank; place the rectangular blank on a high-precision special deep hole drilling and boring machine with a guide device for processing, and drill holes at both ends according to the coordinate position to reduce the position error when processing the guide hole and improve the processing accuracy.

[0007] S3, filling the guide hole: before the final forming of the copper tube, the guide hole processed in S2 is blocked with a copper plug at one end, and the filler is poured from the other end to fill it up, so as to reduce the deformation of the guide hole and the transmission of extrusion force during the subsequent extrusion forming of the copper tube, and ensure the mold adhesion of the inner cavity.

[0008] S4. Copper tube extrusion molding: Use an arc-shaped core rod that is consistent with the geometric dimensions and curvature parameters of the inner cavity of the crystallizer copper tube to penetrate into the rectangular blank, and then, driven by a horizontal hydraulic press, make the copper tube pass through a concave die that is consistent with the cross-sectional dimensions of the copper tube, thereby completing the extrusion molding of the arc-shaped crystallizer copper tube.

[0009] S5. Clean and repair the guide hole: After extrusion molding, clean the filler in the guide hole; after cleaning, repair the guide hole to ensure that the size and roundness of the guide hole meet the requirements of the drawing.

[0010] S6. Sawing and milling processing: trim the total length of the copper tube according to the requirements of the drawing, saw the two ends of the copper tube of the guide hole type arc crystallizer, and process the pallet groove to complete the processing of the copper tube of the guide hole type arc crystallizer.

[0011] Furthermore, the inner cavity size of the rectangular blank is 6-8 mm larger than the inner cavity of the finished copper tube to ensure the smooth insertion of the subsequent arc core rod; the wall thickness of the rectangular blank is made according to a deformation rate of 18%, that is: the wall thickness of the rectangular blank X=S / (1-18%): wherein: S is the theoretical wall thickness of the finished product; the rectangular blank is in an annealed state.

[0012] Furthermore, the processing of the guide holes belongs to the category of fine deep hole processing, which requires not only ensuring the spacing size of the holes, but also ensuring the processing direction of the holes and the position tolerance between the inner cavity of the copper tube and the holes; when processing the guide holes: the rectangular blank is placed on a high-precision special deep hole drilling and boring machine with a guide device for processing, and the guide holes are drilled by drilling at both ends according to the coordinate position to reduce the position error when drilling the guide holes and improve the processing accuracy.

[0013] Furthermore, tin-bismuth alloy is selected as filler to reduce the ellipticity error of the guide hole; when filling, all holes at one end of the copper tube with the bottom are plugged with a conical copper plug and hammered tightly, the copper tube is preheated to 130° C. and placed with the bottom end facing downward; the tin-bismuth alloy block is heated to 160-180° C. in a crucible, and the molten tin-bismuth alloy liquid is poured into the guide hole to fill it, and the copper tube is formed and stretched after it is cooled to room temperature to minimize the deformation of the guide hole and ensure that the inner cavity of the copper tube fits the surface of the core rod.

[0014] Furthermore, in the copper tube extrusion forming process, the arc core rod is connected to the slider of the horizontal hydraulic press through a pin shaft through a hole at one end, and then the straight square blank is sleeved on the arc core rod, and the other end of the arc core rod is pushed to the bottom of the inner cavity of the straight square blank; the die is placed against the die base plate on the hollow beam of the horizontal hydraulic press, and the arc core rod moves under the drive of the slider of the horizontal hydraulic press, thereby driving the straight square blank into the die. Since the straight square blank in the annealed state has good plasticity and ductility, the straight square blank is When passing through the die, under the extrusion of the die, the inner cavity of the straight square blank gradually adheres to the surface of the arc core rod, and extends along the arc core rod. At the same time, under the action of extrusion resistance, the position of the die changes with the position of the arc core rod, that is: the angle of the die swings with the arc surface behind it, and the upper and lower positions slide along the die base plate; when the straight square blank passes through the die as a whole, the extrusion molding of the copper tube is completed, and then a guide hole type arc crystallizer copper tube with an inner cavity and an outer shape that meet the requirements is extruded.

[0015] Furthermore, when cleaning and repairing the diversion hole: a steel receiving tray is placed at the bottom of the pit-type heat treatment furnace, and the bottom end of the extruded copper tube is placed upright on the receiving tray; the copper tube is heated to 150°C, and the molten tin-bismuth alloy flows into the steel receiving tray for recovery; a ball-end rotary file consistent with the design dimensions of the drawing is used, and an extension rod is used in conjunction with the extension rod, the length of the extension rod is 60% of the total length of the copper tube, and a diameter of Φ5 cold-drawn steel bar is used, which is butt-welded to the handle of the ball-end rotary file; a hand drill or a horizontal milling machine is used as the power, and the ball-end rotary file head is used to expand and repair the diversion hole from both ends, and it is ensured that the sum of the expansion depths at both ends is not less than the total length of the copper tube; because the ball-end rotary file is guided by the hole, the extension rod used is elastic and bends with the hole, thereby achieving the expansion of the elliptical diversion hole, ensuring that the size and roundness of the diversion hole meet the requirements of the drawing.

[0016] Furthermore, the two ends of the copper tube of the guide hole type arc crystallizer are sawed, and a processing allowance of 5-10mm is left at each end, the total length of the copper tube is trimmed, and the pallet groove is processed, thereby completing the processing of the copper tube of the guide hole type arc crystallizer.

[0017] Furthermore, the material of the crystallizer copper tube is chromium-zirconium copper or silver-copper; when chromium-zirconium-copper material is selected, the components are proportioned by weight as follows: Cr: 0.9%, Zr: 0.2%, and the rest are Cu; when silver-copper material is selected, the components are proportioned by weight as follows: Cu+Ag≥99.9%, Ag: 0.08-0.12%; P: 0.004-0.012%.

[0018] Compared with the prior art, the present invention has the following advantages: (1) the present invention can ensure that the major axis of the cross section of the elliptical guide hole after extrusion molding is consistent with the size of the finished hole, and can also ensure that the processing allowance during subsequent hole expansion is minimized, reduce the position error when drilling the guide hole, and improve the processing accuracy; (2) the present invention uses tin-bismuth alloy, which has a low melting point and moderate hardness after cooling, and can well ensure the support of the guide hole and extension with the hole during subsequent cold extrusion, facilitate injection operation and subsequent cleaning, is non-toxic, and improves the shrinkage and flattening of the guide hole; (3) the present invention uses tin-bismuth alloy, which has a low melting point and moderate hardness after cooling, and can well ensure the support of the guide hole and extension with the hole during subsequent cold extrusion, facilitate injection operation and subsequent cleaning, is non-toxic, and improves the shrinkage and flattening of the guide hole; The copper tube extrusion molding process of the invention can extrude a guide hole type arc-shaped crystallizer copper tube whose inner cavity and outer shape meet the requirements; (4) In the prior art, the ellipticity requirements of the hole cannot be guaranteed when the guide hole is cleaned and repaired. The only way is to enlarge the size of the pre-drilled guide hole to ensure that the cross-sectional area of ​​the finished hole is equivalent to the design to meet the performance requirements, but it cannot ensure that the size of the guide hole meets the requirements of the drawing. Through the secondary processing of the guide hole using a spherical rotary file with an extension rod of the present invention, a product that meets the requirements of the drawing can be processed, solving the problem of the hole shape not being consistent with the drawing. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the extrusion molding of the copper tube of the guide hole type crystallizer of the present invention.

[0020] Figure 2 It is a front view of the guide hole type crystallizer copper tube of the present invention.

[0021] Figure 3 For the present invention Figure 2 Cross-sectional view along the AA direction.

[0022] Figure 4 It is a schematic diagram comparing the ideal contour and the actual contour of the guide hole after extrusion molding of the crystallizer copper tube of the present invention.

[0023] Figure 5 It is a schematic diagram of the structure of the ball-end rotary file and the extension rod of the present invention.

[0024] Figure 6 The rectangular blank structure of the crystallizer copper tube of the present invention is shown in FIG. Figure 1 .

[0025] Figure 7 The rectangular blank structure of the crystallizer copper tube of the present invention is shown in FIG. Figure 2 .

[0026] Figure 8 Schematic diagram of the rectangular blank of the crystallizer copper tube of the present invention after processing the guide hole Figure 1 .

[0027] Fig. 9 Schematic diagram of the rectangular blank of the crystallizer copper tube of the present invention after processing the guide hole Figure 2 .

[0028] Figure numbers: 1-arc core rod; 2-filler; 3-rectangular blank; 4-die; 5-copper plug; 6-ideal contour line of the guide hole; 7-actual contour line of the guide hole; 8-extension rod; 9-ball-end rotary file handle; 10-ball-end rotary file head. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention but are not intended to limit the present invention.

[0030] The present invention proposes a processing technology for a guide hole type arc-shaped crystallizer copper tube, comprising the following steps: S1. Preparation of a straight square blank 3 of a copper tube: The copper tube blank is drawn into a straight square blank 3 on a horizontal hydraulic press through a straight core rod and a square die. The copper tube blank needs to be made into a structure with a half bottom, and the bottom is used as a process head. The process head is used to press against the end of the straight core rod to limit the movement of the copper tube blank and the straight core rod, so as to achieve relative movement between the square die and the copper tube blank during extrusion molding; the inner cavity size of the straight square blank 3 is 6-8mm larger than the inner cavity of the copper tube finished product to ensure the smooth insertion of the subsequent arc core rod 1; the wall thickness is made according to a deformation rate of 18%, that is, the wall thickness of the straight square blank X=S / (1-18%): where: S is the theoretical wall thickness of the finished product, and the straight square blank 3 is required to be in an annealed state.

[0031] S2. Processing of guide holes: Since the finished crystallizer copper tube is arc-shaped, the path direction of the guide hole is consistent with the arc shape of the copper tube. The arc-shaped deep hole cannot be directly processed by mechanical processing methods, and can only be pre-processed in the straight tube stage of the copper tube as a rectangular blank 3. In the subsequent stretching forming process, the rectangular blank 3 needs to undergo a stretching and over-molding process, which not only ensures that the rectangular blank 3 fits the arc-shaped core rod 1, but also has a stretching and lengthening process, resulting in the guide hole being elongated and shrunk, and also having a "flattened" shape change; therefore, the size of the processed guide hole should be larger than the aperture specified in the finished product design; after experimental comparison, the guide hole processing needs to be pre-drilled in the straight tube stage of the rectangular blank 3 into a through hole about 12% larger than the diameter specified in the drawing, so that it can ensure that the major axis of the elliptical guide hole cross-section after extrusion is consistent with the size of the finished hole, and can also ensure that the processing allowance during subsequent hole expansion is minimized. The processing of the guide hole belongs to the category of fine deep hole processing, which requires not only the spacing size of the holes, but also the position tolerance between the processing direction of the holes and the inner cavity of the copper tube and between the holes. The rectangular blank 3 is placed on a high-precision special deep hole drilling and boring machine with a guide device for processing, and the holes are drilled by drilling at both ends according to the coordinate position to reduce the position error when drilling the guide hole and improve the processing accuracy.

[0032] S3, filling the guide hole: In order to reduce the deformation of the guide hole in the subsequent stretching process of the copper tube, it is necessary to use filler 2 to fill the guide hole before the copper tube is extruded. In the past, the materials commonly used to fill the guide hole include river sand, fine steel balls, plastics, etc., but these methods have their own disadvantages. For example, river sand and fine steel balls have a certain effect on improving the elliptical phenomenon of the hole, but they are difficult to clean. The molten plastic is poured in, extruded and then melted and removed. Although it is easier to clean, the plastic has a low hardness and is not ideal for improving the shrinkage and flattening of the hole. Since copper materials will begin to recrystallize when the temperature exceeds 200°C, when using filling materials that flow out through the melting method, it is also necessary to consider that the temperature required for heating cannot be greater than 200°C to avoid affecting the hardness and other properties of the copper tube matrix due to heating. The tin-bismuth alloy (tin content of 42%, bismuth content of 58%, melting point of 138 degrees) is selected because of its low melting point and moderate hardness after cooling, which can well ensure the support and extension of the guide hole during subsequent cold extrusion, facilitate injection operation and subsequent removal, non-toxic, and better than the above-mentioned materials in improving the shrinkage and flattening of the guide hole, so the tin-bismuth alloy should be preferably used as the filler 2. When filling, all the holes at one end of the copper tube with the bottom are first plugged and hammered with a conical copper plug 5 with a length of about 15 mm, and the copper tube is preheated to about 130°C by baking or other methods, and placed with the bottom end facing down. Then take an appropriate amount of tin-bismuth alloy block, heat it to 160-180°C in a crucible, pour the molten tin-bismuth alloy liquid into the hole to fill it, and then extrude it after cooling to room temperature to minimize the deformation of the guide hole and ensure that the inner cavity of the copper tube fits the surface of the arc core rod 3; the tin-bismuth alloy material is used for filling, which effectively improves the ellipticity error of the hole.

[0033] S4. Copper tube extrusion molding: After the filler is filled in the copper tube guide hole, the copper tube is extruded into a curved square billet copper tube at room temperature through the curved core rod 1 and the die 4 on a horizontal hydraulic press at one time, and the inner cavity matches the curved core rod 1 and the outer cross-section meets the outer dimensions of the copper tube.

[0034] During the extrusion process, the arc core rod 1 is connected to the slider of the horizontal hydraulic press through the hole at the left end through the pin shaft, and then the straight square blank 3 is sleeved on the arc core rod 1, and the right end of the arc core rod 1 should be pushed against the bottom of the inner cavity of the straight square blank 3. The die 4 is close to the die base plate on the hollow beam of the hydraulic press, and the arc core rod 1 is driven by the slider of the hydraulic press to move horizontally to the right, driving the straight square blank 3 into the die 4. Since the straight square blank 3 in the annealed state has good plasticity and ductility, when the straight square blank 3 passes through the die 4, under the extrusion of the die 4, the inner cavity of the straight square blank 3 gradually closes to the surface of the arc core rod 1, and it will also extend to the left along the arc core rod 1. At the same time, under the action of the extrusion resistance, the position of the die 4 will change with the position of the arc core rod 1, that is, the angle of the die 4 swings with the arc surface behind it, and the upper and lower positions can slide along the die base plate. The extrusion molding process of the copper tube is completed until the rectangular blank 3 passes through the concave die 4. Through the above extrusion molding process, a guide hole type arc crystallizer copper tube with an inner cavity and an outer shape that meet the requirements can be extruded.

[0035] During the extrusion process, since the arc core rod 1 is hinged by a pin, as the extrusion force changes, the right end of the arc core rod 1 can swing in a small range around the pin hole at the left end. Although the die 4 is limited in the horizontal direction by the die seat on the hydraulic press beam, the die 4 can change with the tensile force and the arc angle. Through the arc structure on both sides of the back of the die 4, it can roll through the back arc structure or slide on the die seat plate as the force changes during the copper tube extrusion process. In this way, through this extrusion and stretching process, the inner cavity of the copper tube is consistent with the arc core rod 1 in terms of size, curvature, taper and other geometric parameters, and the cross-sectional size is consistent with the die 4.

[0036] S5. Clean and repair the guide holes: Place a steel receiving tray at the bottom of the pit-type heat treatment furnace, and place the extruded copper tube strip upright on the receiving tray with the bottom end facing upwards. Heat the copper tube to about 150°C, and the molten tin-bismuth alloy flows into the tray for recovery. After the guide holes are filled with tin-bismuth alloy and the copper tube is extruded and drawn, the guide holes will have an obvious "flattened" elliptical phenomenon under the combined action of the extrusion and stretching forces. Usually, the long axis of the elliptical guide hole will be reduced by about 12%, and the short axis will be reduced by about 20%. The ideal contour line 6 of the guide hole and the actual contour line 7 of the guide hole are as shown in the figure. Figure 4 As shown; use a ball-end rotary file consistent with the design size of the drawing to cooperate with an extension rod 8, the length of the extension rod 8 is 60% of the total length of the copper tube, the diameter is Φ5 cold-drawn steel bars, and it is welded to the handle of the ball-end rotary file 9; use a hand drill or a horizontal milling machine as the power, and use the ball-end rotary file head 10 to expand and repair the guide hole from both ends. And ensure that the sum of the expansion depths at both ends is not less than the total length of the copper tube. Since the ball-end rotary file can be guided by the hole, the extension rod 8 used must have a certain elasticity and can bend with the hole, so that the expansion of the elliptical guide hole can be achieved. After processing, the size and roundness of the hole can be guaranteed to meet the requirements of the drawing.

[0037] S6. Sawing and milling: According to the requirements of the drawings, when milling the copper tube: saw the two ends of the copper tube of the guide hole type arc crystallizer, leave a processing allowance of 5-10mm at each end, trim the total length of the copper tube according to the requirements of the drawings, process the pallet groove, etc., and then complete the processing of the copper tube of the guide hole type arc crystallizer.

[0038] like Figure 1-Figure 9 As shown, the present invention provides two kinds of processing technology of guide hole type arc-shaped crystallizer copper tube: Example 1: A guide hole type curved crystallizer copper tube made of chrome zirconium copper is manufactured, with an inner cavity size of width 165mm×height 163mm×length 1000mm, an arc radius R10000mm, and a wall thickness of 30mm; the diameter of the guide hole is φ10, and the guide hole type curved crystallizer copper tube made of chrome zirconium copper has a total of 36 guide holes, and each surface of the crystallizer copper tube has 9 guide holes; the processing flow is as follows: A rectangular blank 3 of a copper tube made of chromium-zirconium-copper is prepared: the material ratio (weight %) of chromium-zirconium-copper is: Cr: 0.9%, Zr: 0.2%, and the rest are Cu. The inner cavity size of the rectangular blank 3 is width 171 mm×height 169 mm, and the wall thickness is: 30 / (1-18%)≈36.5 mm; the effective material length of the rectangular blank 3 is about 850 mm, and the total length including the bottom is 890 mm; the copper tube blank made of chromium-zirconium-copper is drawn into a rectangular blank 3 on a horizontal hydraulic press through a straight core rod and a square die. The copper tube blank needs to be made into a structure with a half bottom, and the bottom is used as a process head. The process head is used to press against the end of the straight core rod to limit the movement of the copper tube blank and the straight core rod, so as to achieve relative movement between the square die and the copper tube blank during extrusion molding.

[0039] Processing guide holes: The guide hole of the finished copper tube of the crystallizer is φ10 in diameter, and the pre-drilled guide hole is φ11.2 in diameter. It needs to penetrate the entire length of the copper tube blank of 890mm. The guide hole belongs to fine deep hole processing, which requires high processing accuracy and the internal deflection error of the entire length is not more than 0.5mm; in order to ensure the processing accuracy of the guide hole, ensure the hole spacing size, the position tolerance between the hole and the inner cavity of the copper tube, and the hole and the hole, the guide hole must be processed on a high-precision special deep hole boring machine with a guide device, and the two ends are drilled to reduce the processing error of the deep hole and improve the processing accuracy.

[0040] Filling the guide holes: All the guide holes processed above are plugged with a conical copper plug 5 with a small end diameter of φ11 and a length of about 15 mm at the right end and hammered tightly. After completion, the right end is turned downward and the guide holes are filled with a tin-bismuth alloy solution (tin content of 42%, bismuth content of 58%, melting point of 138 degrees), and then extruded after cooling to room temperature; the guide holes are filled with lead-tin alloy and then extruded to reduce the deformation of the guide holes and ensure the mold-fitting effect between the inner cavity and the arc core rod 1.

[0041] Copper tube extrusion molding: At room temperature, an arc core rod 1 with a cross-sectional size of width 165mm x height 163mm x length 1500mm and an arc radius of R10000mm is hinged on the die base of the horizontal hydraulic press slider, and then the rectangular blank 3 with the guide hole filled with tin-bismuth alloy is sleeved on the arc core rod 1, and the die 4 is suspended and attached to the template of the front beam of the hydraulic press. The arc core rod 1 is operated and the position of the die 4 is adjusted so that the arc core rod 1 and the rectangular blank 3 pass through the die 4. After the extrusion molding of the copper tube is completed, the material is withdrawn.

[0042] Clean and repair the guide hole: put a steel contact plate into the bottom of the pit heat treatment furnace, support the bottom of the copper tube upward and place it on the contact plate, use the pit heat treatment furnace to heat the copper tube to about 150℃, and the tin-bismuth alloy filled in the guide hole will melt and flow out. After the guide hole filled with tin-bismuth alloy is extruded into the copper tube, the guide hole will be obviously "flattened" into an ellipse under the action of the extrusion force. Usually, the long axis of the elliptical guide hole will be reduced by about 12%, and the short axis will be reduced by about 20%; the pre-drilled diameter of the guide hole is φ11.2mm, and the long axis is shortened to about 10mm and the short axis is about 8.9mm after extrusion. In order to ensure the dimensional accuracy of the hole, a standard ball-end rotary file with a diameter of φ10 and a file handle diameter of φ6 is used, and a cold-drawn steel bar extension rod 8 with a diameter of φ5 is connected. The length of the extension rod 8 is 600, and it is connected to the ball-end rotary file handle 9 by welding. The φ5 cold-drawn steel bar used can not only meet the strength of the torque required for the extension rod 8 to expand the hole, but also ensure the elastic deformation requirements of the arc path of the hole to the extension rod 8; use a hand drill with a power of not less than 500W, clamp the end of the extension rod 8 through the drill clamp, extend the extension rod 8 into the diversion hole, start the hand drill, and use the ball-end rotary file head 10 to complete the expansion and repair of the diversion hole. After the repair, it can be ensured that the size and roundness of the diversion hole meet the requirements of the drawing.

[0043] Sawing and milling processing: According to the requirements of the drawings, saw the heads of both ends of the copper tube of the guide hole type arc crystallizer, leaving a processing allowance of 5-10mm at each end, and then trim the total length of the copper tube according to the requirements of the drawings, process the pallet groove, etc., and then complete the processing of the copper tube of the guide hole type arc crystallizer. Embodiment 2:

[0044] The silver-copper-made guide hole arc-shaped crystallizer copper tube has an inner cavity size of 170mm width, 168mm height, and 1000mm length, an arc radius of R8000mm, a wall thickness of 25mm, and a guide hole diameter of φ12. The silver-copper-made guide hole arc-shaped crystallizer copper tube has a total of 32 guide holes, and each surface of the crystallizer copper tube has 8 guide holes. The processing steps are as follows:

[0045] A copper tube made of silver-copper is prepared as a square blank 3: the material ratio of silver-copper (weight %) is: Cu+Ag≥99.9%, Ag: 0.08-0.12%; P: 0.004-0.012%; the inner cavity size of the square blank 3 is width 176mmXheight 174mm, and the wall thickness is: 25 / (1-18%)≈30.5mm; the effective material length is about 850mm, and the total length including the bottom is 880mm; the copper tube blank made of silver-copper is drawn into a square blank 3 on a horizontal hydraulic press through a straight core rod and a square die. The copper tube blank needs to be made into a structure with a half bottom, and the bottom is used as a process head. The process head is used to press against the end of the straight core rod to limit the movement of the copper tube blank and the straight core rod, so as to achieve relative movement between the square die and the copper tube blank during extrusion molding.

[0046] Processing guide holes: The diameter of the guide holes of the finished copper tube is φ12, and the diameter of the pre-drilled guide holes is Φ13.4. It needs to penetrate the entire length of the copper tube blank of 880mm. The guide holes belong to fine deep hole processing, which requires high processing accuracy and the internal deflection error of the entire length is not more than 0.5mm; in order to ensure the processing accuracy of the guide holes, ensure the hole spacing size, and the position tolerance between the holes and the inner cavity of the copper tube and between the holes, the guide holes must be processed on a high-precision special deep hole boring machine with a guide device, and the two ends are drilled to reduce the processing error of the guide holes and improve the processing accuracy.

[0047] Filling the guide holes: The right ends of all the guide holes processed above are plugged tightly with a conical copper plug 5 with a small end diameter of φ13 and a length of about 15 mm. After completion, the right ends are turned downward and a tin-bismuth alloy solution (tin content 42%, bismuth content 58%, melting point 138 degrees) is poured in, cooled to room temperature and then extruded.

[0048] Copper tube extrusion molding: At room temperature, an arc core rod 1 with a cross-sectional size of width 170mmX height 168mmX length 1500mm and an arc radius of R8000mm is hinged on the die base of the horizontal hydraulic press slider, and then the rectangular blank 3 with the guide hole filled with tin-bismuth alloy is sleeved on the arc core rod 1, and the die 4 is suspended and attached to the template of the front beam of the hydraulic press. The arc core rod 1 is operated and the position of the die 4 is adjusted so that the arc core rod 1 and the rectangular blank 3 pass through the die 4. After the copper tube extrusion molding is completed, the material is withdrawn.

[0049] Clean and repair the guide hole: put a steel receiving plate into the bottom of the pit heat treatment furnace, support the bottom of the copper tube upward and place it above the contact plate. The pit heat treatment furnace heats the copper tube to about 150°C, and the tin-bismuth alloy filler in the guide hole melts and flows out. After the copper tube is extruded, the guide hole will be obviously "flattened" into an ellipse under the action of the extrusion force. Usually, the long axis of the elliptical guide hole is reduced by about 12%, and the short axis is reduced by about 20%. The pre-drilled diameter of the guide hole is φ13.4. After extrusion, the long axis is shortened to about 12mm and the short axis is about 10.7mm. In order to ensure the dimensional accuracy of the guide hole, a standard ball-end rotary file with a diameter of φ12 and a file handle of φ6 is used to connect the cold-drawn steel bar extension rod 8 with a diameter of φ5. The length of the extension rod 8 is 600mm, and it is connected to the ball-end rotary file handle 9 by welding. The use of φ5 cold-drawn steel bars can not only meet the strength of the torque required for the expansion of the extension rod 8, but also ensure the elastic deformation requirements of the arc path of the hole to the extension rod 8; a hand drill with a power of not less than 500W is used to clamp the end of the extension rod 8 through a drill clamp, and a ball-end rotary file head 10 is used to complete the expansion and repair of the diversion hole. After processing, the size and roundness of the diversion hole can be guaranteed to meet the requirements of the drawing.

[0050] Sawing and milling processing: According to the requirements of the drawings, saw the heads of both ends of the copper tube of the guide hole type arc crystallizer, leaving a processing allowance of 5-10mm at each end, and then trim the total length of the copper tube according to the requirements of the drawings, process the pallet groove, etc., and then complete the processing of the copper tube of the guide hole type arc crystallizer.

Claims

1. The processing technology of the guide hole type arc-shaped crystallizer copper tube is characterized in that: The following steps are involved: S1, preparing a copper tube rectangular blank (3): drawing the copper tube blank with a half-bottom structure into a copper tube rectangular blank (3) on a horizontal hydraulic press through a straight core rod and a square die; S2. Processing the guide hole: When processing the guide hole: pre-drill a through hole on the rectangular blank (3) that is 12% larger than the diameter design size of the hole in the drawing; place the rectangular blank (3) on a high-precision special deep hole drilling and boring machine with a guide device for processing, and drill the hole using a two-end drilling method according to the coordinate position to reduce the position error when processing the guide hole and improve the processing accuracy; S3, filling the guide hole: before the copper tube is finally formed, the guide hole processed in S2 is first plugged with a copper plug (5) at one end, and the filler (2) is poured from the other end to fill and enrich it, so as to reduce the deformation of the guide hole and the transmission of extrusion force during the subsequent extrusion molding of the copper tube, and ensure that the inner cavity is mold-fitted; S4, copper tube extrusion molding: a curved core rod (1) having the same geometric dimensions and curvature parameters as the inner cavity of the copper tube of the crystallizer is inserted into the rectangular blank (3), and then, driven by a horizontal hydraulic press, the copper tube is passed through a concave die (4) having the same cross-sectional dimensions as the outer shape of the copper tube, thereby completing the extrusion molding of the curved crystallizer copper tube; S5. Cleaning and repairing the guide hole: After extrusion molding, the filler (2) in the guide hole is cleaned; after cleaning, the guide hole is repaired to ensure that the size and roundness of the guide hole meet the requirements of the drawing; S6. Sawing and milling processing: trim the total length of the copper tube according to the requirements of the drawing, saw the two ends of the copper tube of the guide hole type arc crystallizer, and process the pallet groove to complete the processing of the copper tube of the guide hole type arc crystallizer.

2. The processing technology of the guide hole type arc-shaped crystallizer copper tube according to claim 1 is characterized in that: The inner cavity size of the rectangular blank (3) is 6-8 mm larger than the inner cavity of the finished copper tube to ensure smooth insertion of the subsequent arc core rod; the wall thickness of the rectangular blank (3) is produced according to a deformation rate of 18%, that is, the wall thickness of the rectangular blank X=S / (1-18%): wherein S is the theoretical wall thickness of the finished product; the rectangular blank (3) is in an annealed state.

3. The processing technology of the guide hole type arc-shaped crystallizer copper tube according to claim 1 is characterized in that: The processing of the guide holes belongs to the category of fine deep hole processing, which requires not only the spacing size of the holes, but also the processing direction of the holes and the position tolerance between the inner cavity of the copper tube and the holes. When processing the guide holes: the rectangular blank (3) is placed on a high-precision special deep hole drilling and boring machine with a guide device for processing, and the guide holes are drilled by drilling at both ends according to the coordinate position to reduce the position error when drilling the guide holes and improve the processing accuracy.

4. The processing technology of the guide hole type arc-shaped crystallizer copper tube according to claim 1 is characterized in that: A tin-bismuth alloy is selected as the filler (2) to reduce the ellipticity error of the guide hole; when filling, all holes at one end of the copper tube with the bottom are plugged with a conical copper plug (5) and hammered tightly, the copper tube is preheated to 130° C. and placed with the bottom end facing downward; a tin-bismuth alloy block is heated to 160-180° C. in a crucible, and molten tin-bismuth alloy liquid is poured into the guide hole to fill it up, and after the copper tube is cooled to room temperature, it is formed and stretched to minimize the deformation of the guide hole and ensure that the inner cavity of the copper tube fits the surface of the core rod.

5. The processing technology of the guide hole type arc-shaped crystallizer copper tube according to claim 1 is characterized in that: During the copper tube extrusion forming process, the arc core rod (1) is connected to the slider of the horizontal hydraulic press through a hole at one end thereof via a pin, and then the straight square blank (3) is sleeved onto the arc core rod (1), and the other end of the arc core rod (1) is pushed against the bottom of the inner cavity of the straight square blank (3); the die (4) is placed against the die base plate on the hollow beam of the horizontal hydraulic press, and the arc core rod (1) is moved under the drive of the slider of the horizontal hydraulic press, thereby driving the straight square blank (3) into the die (4). Since the straight square blank (3) in the annealed state has good plasticity and ductility, the straight square blank (3) is pressed against the die base plate on the hollow beam of the horizontal hydraulic press. When passing through the concave die (4), under the extrusion of the concave die (4), the inner cavity of the straight square blank (3) gradually closes to the surface of the arc-shaped core rod (1), and at the same time, it extends and lengthens along the arc-shaped core rod (1). At the same time, under the action of the extrusion resistance, the position of the concave die (4) changes with the running position of the arc-shaped core rod (1), that is, the angle of the concave die (4) swings along the arc surface of the back, and the upper and lower positions slide along the die base plate; when the straight square blank (3) passes through the concave die (4) as a whole, the extrusion molding of the copper tube is completed, and then a guide hole type arc-shaped crystallizer copper tube with an inner cavity and an outer shape that meet the requirements is extruded.

6. The processing technology of the guide hole type arc-shaped crystallizer copper tube according to claim 1, characterized in that: When cleaning and repairing the guide hole: a steel receiving tray is placed at the bottom of the pit heat treatment furnace, and the bottom end of the copper tube strip that has been extruded and formed is placed upright on the receiving tray; the copper tube is heated to 150°C, and the tin-bismuth alloy melts and flows into the steel receiving tray for recovery; a ball-end rotary file consistent with the design size of the drawing is used, and an extension rod (8) is used in conjunction with the extension rod (8), the length of the extension rod (8) is 60% of the total length of the copper tube, and the diameter is a Φ5 cold-drawn steel bar, which is butt-welded to the ball-end rotary file handle (9); a hand drill or a horizontal milling machine is used as a power source, and the ball-end rotary file head (10) is used to expand and repair the guide hole from both ends, and it is ensured that the sum of the expansion depths at both ends is not less than the total length of the copper tube; because the ball-end rotary file is guided by the hole, the extension rod (8) used is elastic and bends with the hole, thereby achieving expansion of the elliptical guide hole, and ensuring that the size and roundness of the guide hole meet the requirements of the drawing.

7. The processing technology of the guide hole type arc-shaped crystallizer copper tube according to claim 1 is characterized in that: The two ends of the guide hole type arc crystallizer copper tube are sawed, and a processing allowance of 5-10mm is left at each end. The total length of the copper tube is trimmed, and the pallet groove is processed to complete the processing of the guide hole type arc crystallizer copper tube.

8. The processing technology of the guide hole type arc-shaped crystallizer copper tube according to claim 1, characterized in that: The material of the crystallizer copper tube is chromium-zirconium copper or silver-copper; when chromium-zirconium-copper material is selected, the weight ratio of the components is: Cr: 0.9%, Zr: 0.2%, and the rest is Cu; when silver-copper material is selected, the weight ratio of the components is: Cu+Ag≥99.9%, Ag: 0.08-0.12%; P: 0.004-0.012%.

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