Manufacturing method of high-uniformity and high-grain-size welded titanium cylinder for cathode roller

Abstract

The present invention discloses a manufacturing method of a welded titanium cylinder with high uniformity and high crystal grain size for a cathode roll, belonging to the field of electrolytic copper foil production equipment. The method includes the following steps: rolling a TA1 titanium plate on a four-roll plate bending machine; performing bevel processing and pre-welding pretreatment on the seam opening of the TA1 titanium cylinder, and using the narrow-gap laser welding method to weld the seam opening of the TA1 titanium cylinder in a spiral swing mode of the laser beam in space; after welding, applying a high-temperature water glass coating on the surface of the TA1 titanium cylinder, and performing high, medium, and low-temperature heating and high, medium, and low-temperature forging; performing heat treatment on the forged TA1 titanium cylinder; performing rough machining on the inner and outer surfaces of the TA1 titanium cylinder; installing the TA1 titanium cylinder on the four-roll plate bending machine for roundness correction; unloading the TA1 titanium cylinder, using the ultrasonic impact method to remove the residual stress on the surface of the TA1 titanium cylinder, and performing finish machining on the surface of the TA1 titanium cylinder. The present invention has the advantages of high welding efficiency, narrow weld seam and welding heat affected zone, uniform and fine overall crystal grains of the TA1 titanium cylinder, and low residual stress.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrolytic copper foil production equipment, and particularly relates to a manufacturing method of a welded titanium cylinder with high uniformity and high crystal grain size for a cathode roll. Background Art

[0002] Electrolytic copper foil is one of the basic materials for manufacturing electronic products such as copper clad laminates, printed circuit boards, and lithium-ion batteries. With the rapid development of science and technology in the downstream industrial fields, the demand for upstream electrolytic copper foil has been increasing year by year, especially the requirements for the quality and quality of copper foil are getting higher and higher. The cathode roll is the mother of electrolytic copper foil. The smooth surface of the copper foil is a copy of the surface of the titanium cylinder. The quality of the titanium cylinder used for the cathode roll directly determines the quality and performance of the copper foil. At present, the manufacturing of the TAI titanium cylinder on the surface of the cathode roll mainly has two forming manufacturing processes: spinning and welding. Among them, the seamless titanium cathode roll manufactured by the spinning process has the advantages of uniform surface crystal grain size and uniform and dense copper foil produced. However, before the spinning of the titanium cylinder ring blank, it needs to go through processes such as vacuum melting of sponge titanium, ingot splitting, forging, punching, hole expanding, ring rolling, ring turning, and spinning. The process is complex, the construction period is long, and the material utilization rate is low. In contrast, the welded cathode roll has the advantages of low cost and high production efficiency. However, the disadvantage of the welded TA1 titanium cylinder is that there are obvious color differences on the roll surface of the cathode roll, resulting in periodic bright bands in the copper foil produced, affecting the quality and quality of the copper foil. Therefore, it is urgent to develop a preparation technology for TA1 titanium cylinders for cathode rolls with low cost, high efficiency, high crystal grain size, and high uniformity.

[0003] Chinese Patent CN102489942B discloses a manufacturing method of a seamless titanium cylinder for a cathode roll. The chemical composition (weight percentage) of the selected titanium ingot block is: Fe < 0.06, O < 0.06, C < 0.02, N < 0.02, H < 0.01, other impurity elements single < 0.05, and the total content of other elements < 0.2. The selected titanium ingot block is subjected to hole expanding and drawing to obtain a blank before ring rolling of the titanium cylinder. The spun blank after turning is heated and spun through 3 - 4 passes to obtain a preliminarily formed cathode roll titanium cylinder; the preliminarily formed cathode roll titanium cylinder is subjected to annealing heat treatment to finally obtain a formed cathode roll titanium cylinder. Through reasonable parameter control, the obtained titanium cylinder has an ovality ≤ 3 mm, a diameter tolerance ≤ 2 mm, a wall thickness tolerance ≤ 0.5 mm, and the crystal grain size of the microstructure metallographic inspection is 6 - 8 grades. However, since the manufacturing process of the seamless titanium cylinder for the cathode roll needs to go through multiple processes, including vacuum melting of sponge titanium, ingot splitting, forging, punching, hole expanding, ring rolling, ring turning, spinning and other process steps, the process is complex, the construction period is long, and the material utilization rate is low.

[0004] Chinese Patent CN1740403A discloses a manufacturing method of a large-sized titanium cathode roll cylinder and a composite large-current cathode roll made of this material. The manufacturing method is as follows: Heat both ends of the titanium plate and then perform die pressing to form flanges with a certain height; Roll the titanium plate into a cylinder, butt the flanges formed by die pressing, and fully weld the butt joint; Heat the weld and then perform forging, roll the forged weld, and finally perform overall heat treatment on the titanium cylinder. The main shaft of the composite large-current cathode roll made of this material is axially located inside the roll cylinder. The roll cylinder is fixedly connected to the main shaft through conductive wheels and copper conductive plates. Both ends of the roll cylinder are sealed with end plates. The roll cylinder is formed by hot-fitting an outer titanium cylinder and an inner steel-copper composite cylinder with steel wrapping copper. This invention uses the method of end die pressing to process a height that can be forged, which is simple and feasible. Folding is not easily formed during forging. After forging and then rolling, the weld structure can be further improved. The produced titanium cylinder has a low cost and high quality. The cathode roll made of this material can ensure the uniformity of conductivity when a large current is input. When the input current is 35,000A, the surface of the roll cylinder does not overheat, improving the current density on the roll surface and the output and quality of the foil, and extending the service life of the cathode roll. However, since welding the titanium cylinder will form a longitudinal seam on its surface, and during the welding process, due to the increase in temperature, the grains at the weld grow. Although subsequent heat treatment and forging will improve the weld structure, the grain size of the weld cannot be completely consistent with that of the base material, resulting in obvious color differences on the surface of the cathode roll and a bright band on the surface of the produced copper foil, seriously affecting the quality and production efficiency of the copper foil.

[0005] Therefore, it is necessary to provide a preparation technology for a high-uniformity and high-grain-size welded titanium cylinder for cathode rolls to solve the above problems. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a manufacturing method of a high-uniformity and high-grain-size welded titanium cylinder for cathode rolls. By using the narrow-gap laser welding method combined with the laser beam spatial spiral swing mode, it can be ensured that after the TA1 titanium cylinder is welded, the weld is narrow and the weld structure is fine. By performing three-fire high, medium, and low-temperature forging on the whole TA1 titanium cylinder of the cathode roll after welding and combining with the formulated heat treatment process, it can be ensured that the grains of the whole TA1 titanium cylinder are uniform and fine. By using a four-roll plate rolling machine for rounding treatment and combining with ultrasonic impact technology, it can be ensured that the TA1 titanium cylinder has excellent straightness, roundness, and extremely low residual stress.

[0007] The technical solution adopted by the present invention to solve the technical problems is: A manufacturing method of a high-uniformity and high-grain-size welded titanium cylinder for cathode rolls, the manufacturing method includes the following steps:

[0008] Step 1: Measure, detect, and preprocess the incoming TA1 pure titanium plate.

[0009] Step 2: Install the TA1 pure titanium sheet on the four-roll plate bending machine and perform the operations of rounding, including centering, unloading, pre-bending and rolling, to obtain the TA1 titanium cylinder, and then unload the cylinder body;

[0010] Step 3: Machine the groove at the seam of the TA1 titanium cylinder;

[0011] Step 4: Perform pre-welding pretreatment on the slit TA1 titanium cylinder;

[0012] Step 5: Adopt the narrow-gap laser welding method and, under the protection of inert shielding gas, weld the slit of the TA1 titanium cylinder in a spiral swing mode of the laser beam in space;

[0013] Step 6: After the first layer of welding is completed, clean the weld bead, and then repeat the single-layer and single-pass welding until the slit of the TA1 titanium cylinder is filled to form the entire weld seam, complete the welding, and clean the surfaces of the inner and outer welds of the TA1 titanium cylinder again to obtain the welded TA1 titanium cylinder;

[0014] Step 7: Apply a high-temperature water glass coating on the surface of the welded TA1 titanium cylinder and place it in a pit-type high-temperature resistance furnace for the first high-temperature heating;

[0015] Step 8: Take out the TA1 titanium cylinder after high-temperature heating, put asbestos on its outside, and at the same time put an asbestos pad on the surface of the lower anvil of the forging press, cooperate with the pre-heated die, move it to the forging press and perform the first high-temperature forging on the whole through the upper anvil of the forging press;

[0016] Step 9: Apply a high-temperature water glass coating on the surface of the TA1 titanium cylinder after high-temperature forging and place it in a pit-type high-temperature resistance furnace for the second medium-temperature heating;

[0017] Step 10: Take out the TA1 titanium cylinder after medium-temperature heating, put asbestos on its outside, and at the same time put an asbestos pad on the surface of the lower anvil of the forging press, cooperate with the pre-heated die, move it to the forging press and perform the second medium-temperature forging on the whole through the upper anvil of the forging press;

[0018] Step 11: Apply a high-temperature water glass coating on the surface of the TA1 titanium cylinder after medium-temperature forging and place it in a pit-type high-temperature resistance furnace for the third low-temperature heating;

[0019] Step 12: Take out the TA1 titanium cylinder after low-temperature heating, put asbestos on its outside, and at the same time put an asbestos pad on the surface of the lower anvil of the forging press, cooperate with the pre-heated die, move it to the forging press and perform the third low-temperature forging on the whole through the upper anvil of the forging press;

[0020] Step 13: Air-cool the TA1 titanium cylinder after being forged three times at high, medium, and low temperatures by a forging press to room temperature, and then perform heat treatment on the TA1 titanium cylinder to refine the grains of the whole TA1 titanium cylinder;

[0021] Step 14: Rough-machine the inner and outer surfaces of the heat-treated TA1 titanium cylinder so that the surface roughness Ra of its inner surface is ≤ 6.2 μm and the surface roughness Ra of its outer surface is ≤ 4.8 μm;

[0022] Step 15: Install the surface-treated TA1 titanium cylinder on a four-roll plate bending machine for rounding treatment, and unload the TA1 titanium cylinder after the treatment;

[0023] Step 16: Use the ultrasonic impact method to remove the residual stress on the surface of the TA1 titanium cylinder;

[0024] Step 17: Finish-machine the surface of the TA1 titanium cylinder so that the surface roughness Ra of its inner surface is ≤ 3.2 μm and the surface roughness Ra of its outer surface is ≤ 0.8 μm.

[0025] Furthermore, in the said Step 1, the flatness of the width of the TA1 pure titanium plate is 8 - 10 mm / m, and the tensile strength Rm at room temperature of the plate is 300 - 310 Mpa; the mass fractions of the main components of the plate: Ti ≥ 99.15%, impurity components: Fe ≤ 0.20%, O ≤ 0.18%, C ≤ 0.08%, N ≤ 0.03%, H ≤ 0.015%, the mass fraction of other single impurity elements ≤ 0.10%, and the total ≤ 0.40%; the surface roughness Ra of the plate is 2.8 - 3.2 μm; the measurement of the TA1 pure titanium plate is to measure the actual dimensions of the plate, including length, width, and thickness; the inspection of the TA1 pure titanium plate includes appearance quality inspection, component inspection, and ultrasonic non-destructive flaw detection; the pretreatment of the TA1 pure titanium plate is to remove the iron filings and sundries on the plate to prevent dents or damage to the equipment.

[0026] Furthermore, in the said Step 2, the four-roll plate bending machine mainly includes four working shaft rolls, namely the upper shaft roll, the lower shaft roll, the left side roll, and the right side roll; the materials of the four working shaft rolls are all 42CrMo;

[0027] During the centering operation, slowly move the lower shaft roll upward so that the distance between the upper and lower shaft rolls is maintained at 53 - 58 mm, then move the right side roll upward to the same height as the lower shaft roll, and then move the center line of the left side roll upward between the upper and lower shaft rolls, and move the TA1 pure titanium plate between the upper and lower shaft rolls until it abuts against the left side roll, and at this time the centering operation is completed;

[0028] During the material withdrawal operation, lower the left roller to the initial height, move the lower shaft roller upward until the TA1 pure titanium plate contacts the upper shaft roller and the lower shaft roller, rotate the upper shaft roller counterclockwise, and drive the TA1 pure titanium plate to retreat to the right by using the frictional force between the surface of the TA1 pure titanium plate and the upper shaft roller and the lower shaft roller. When the remaining distance at the left end of the TA1 pure titanium plate is 60 - 95 mm, stop rotating the upper shaft roller to complete the material withdrawal.

[0029] During the pre-bending operation, the upper shaft roller and the lower shaft roller clamp the TA1 pure titanium plate, raise the left roller to apply force to bend one end of the TA1 pure titanium plate. When pre-bending the other end, it is not necessary to take out the TA1 pure titanium plate from the equipment. Just move the TA1 pure titanium plate to the other end and perform pre-bending in the same way.

[0030] During the rolling operation, lower the right roller to the initial position, adjust the left roller to the specified position, rotate the upper shaft roller, and drive the TA1 pure titanium plate to move through frictional force to achieve continuous rolling, making the TA1 pure titanium plate undergo continuous bending with equal curvature. When the length of the right edge of the TA1 pure titanium plate is 60 - 95 mm, stop rotating the upper shaft roller to complete the first pass of roll bending. Repeat the above operation until the TA1 titanium cylinder is obtained by rolling. The rolling speed of the rolled plate is 2 - 4 m / min.

[0031] Furthermore, in step three, the type of the groove is Y-shaped. A Y-shaped groove is opened from the inner wall of the TA1 titanium cylinder. The root face size of the groove is 4 - 6 mm, and the single groove angle is 15 - 20 degrees.

[0032] Furthermore, in step four, the pre-welding pretreatment is to first grind the oxide scale on the surface of the groove, and then sequentially pickle, rinse with clean water, wipe with anhydrous ethanol, and dry the surface with a mixed solution of hydrofluoric acid and nitric acid. In the mixed solution of hydrofluoric acid and nitric acid, the volume fraction of hydrofluoric acid is 4 - 6%, the volume fraction of nitric acid is 24 - 36%, and the balance is water.

[0033] Further, in the fifth step, the narrow-gap laser welding method is as follows: welding starts from the inside of the TA1 titanium cylinder, with a laser power of 2500 - 5500 W, a defocus amount of -10 - +20 mm, a welding speed of 40 - 80 mm / min, and a filler material of TA1 pure titanium wire with a diameter of 2.5 - 3 mm. The laser beam forms a first angle with the normal of the plane where the TA1 titanium cylinder slit is located, and the TA1 pure titanium wire forms a second angle with the plane where the TA1 titanium cylinder slit is located. There is no gap between the laser beam incident point and the end of the TA1 pure titanium wire. The first angle is 15 - 20 degrees, and the second angle is 35 - 45 degrees. The inert protective gas is high-purity argon with a purity of 99.99 - 99.999%, and the gas flow rate of the inert protective gas is 18 - 25 L / min; the swing frequency of the laser beam in the spatial spiral swing mode is 150 - 300 HZ, the swing amplitude is 1 - 3 mm, and the spiral lift angle is 15 - 30 degrees.

[0034] Further, in the sixth step, the cleaning method used to clean the weld bead and the inner and outer weld surfaces of the TA1 titanium cylinder after welding is laser cleaning, that is, the laser beam irradiates on the surface of the weld bead layer. Under the aggregation of laser energy, the huge energy of the beam irradiates on the surface to break the oxides between the weld layers, causing them to be instantly peeled off from the substrate.

[0035] Further, in the seventh step, the welded TA1 titanium cylinder is placed in a pit-type high-temperature resistance furnace for heating. The heating process is to heat it at a heating rate of 7 °C / min - 10 °C / min to 540 °C - 570 °C, hold for 20 - 30 min, then heat it at a heating rate of 9 °C / min - 13 °C / min to 830 °C - 860 °C, hold for 30 - 40 min, and finally heat it at a heating rate of 9 °C / min - 13 °C / min to 1050 °C - 1080 °C, hold for 40 - 50 min.

[0036] Further, in the eighth step, the forging press adopts an automatic control forging mode, with an initial forging temperature of 950 - 980 °C and a final forging temperature of 890 - 920 °C; the welded TA1 titanium cylinder is made into an outer diameter of 2700 mm, with a dimensional tolerance of 0 - +25 mm, a width of 1200 - 1350 mm, and a thickness of 32 - 51 mm; the high-temperature forging feed amount is 250 - 350 mm, the reduction amount is 160 - 240 mm, and the high-temperature forging is carried out along the axis direction of the welded TA1 titanium cylinder. After forging from one end of the welded TA1 titanium cylinder to the other end, it rotates 15 - 20° and repeats the forging operation until the surface of the welded TA1 titanium cylinder is all subjected to high-temperature forging by the upper anvil of the forging press. After forging is completed, the welded TA1 titanium cylinder is cooled to room temperature by air cooling.

[0037] Further, in the ninth step, the TA1 titanium cylinder after high-temperature forging is placed in a pit-type high-temperature resistance furnace for heating. The heating process is to heat it at a heating rate of 7°C / min to 10°C / min to 530°C to 560°C, hold for 20 to 30 minutes, and then heat it at a heating rate of 9°C / min to 13°C / min to 830°C to 850°C, and hold for 40 to 50 minutes.

[0038] Further, in the tenth step, the forging press adopts an automatic control forging mode. The initial forging temperature is 735 to 745°C, and the final forging temperature is 685 to 700°C. The TA1 titanium cylinder is made into an outer diameter of 2700 mm, with a dimensional tolerance of 0 to +25 mm, a width of 1300 to 1500 mm, and a thickness of 25 to 44 mm. The feeding amount during medium-temperature forging is 150 to 260 mm, and the reduction amount is 100 to 170 mm. The medium-temperature forging is carried out circumferentially along the TA1 titanium cylinder. After forging one circle from the starting point of the TA1 titanium cylinder, the TA1 titanium cylinder moves axially by 0 to 20 mm, and the forging operation is repeated until the surface of the TA1 titanium cylinder is all subjected to medium-temperature forging by the upper anvil of the forging press. After the forging is completed, the TA1 titanium cylinder is cooled to room temperature by air cooling.

[0039] Further, in the eleventh step, the TA1 titanium cylinder after medium-temperature forging is placed in a pit-type high-temperature resistance furnace for heating. The heating process is to heat it at a heating rate of 7°C / min to 10°C / min to 645°C to 675°C, and hold for 40 to 50 minutes.

[0040] Further, in the twelfth step, the forging press adopts an automatic control forging mode. The initial forging temperature is 545 to 575°C, and the final forging temperature is 505 to 515°C. The TA1 titanium cylinder is made into an outer diameter of 2700 mm, with a dimensional tolerance of 0 to +25 mm, a width of 1400 to 1600 mm, and a thickness of 20 to 26 mm. The feeding amount during low-temperature forging is 85 to 165 mm, and the reduction amount is 55 to 100 mm. The low-temperature forging is carried out along the axial direction of the TA1 titanium cylinder. After forging from one end of the TA1 titanium cylinder to the other end, it rotates 15 to 20° and the forging operation is repeated until the surface of the TA1 titanium cylinder is all subjected to low-temperature forging by the upper anvil of the forging press. After the forging is completed, the TA1 titanium cylinder is cooled to room temperature by air cooling.

[0041] Further, in the seventh, ninth, and eleventh steps, the high-temperature water glass coating is composed of glass protective lubricant, glass protective lubricant, and water. The mass ratio of glass protective lubricant, glass protective lubricant, and water is 4:1:8. During the brushing process, it is ensured that the brushing is carried out unidirectionally from one end of the TA1 titanium cylinder to the other end, and the brushing thickness is 0.6 to 1.2 mm.

[0042] Further, in Steps 8, 10, and 12, the material of the mold is 42CrMo. The preheating process of the mold is to place the mold in a pit-type resistance furnace and heat it to 500°C - 550°C at a heating rate of 10 - 11°C / min, and hold for 30 min.

[0043] Further, in Step 13, the heat treatment of the TA1 titanium cylinder is as follows: Place the TA1 titanium cylinder cooled to room temperature in a pit-type resistance furnace. Set the heat treatment process to heat it to 300 - 350 °C at a heating rate of 5 - 8°C / min, then heat it to 550 - 565 °C at a heating rate of 7 - 9°C / min, hold for 30 - 40 min, then open the furnace lid, wait for it to cool to room temperature and then take it out, and then sample and test its average grain size grade.

[0044] Further, in Step 14, rough machining is performed on the inner and outer surfaces of the heat-treated TA1 titanium cylinder. When machining, a CNC lathe is used. After fixing the TA1 titanium cylinder to the corresponding fixture, turning machining is performed on the inner and outer surfaces of the TA1 titanium cylinder respectively according to the feed path planned by the program. Among them, different specifications of tools need to be replaced when machining the inner and outer surfaces. Finally, the surface roughness Ra of the inner surface ≤ 6.2 μm, and the surface roughness Ra of the outer surface ≤ 4.8 μm.

[0045] Further, in Step 15, installing the TA1 titanium cylinder on a four-roll plate bender for rounding mainly includes three steps: loading, rolling, and unloading. Among them, loading is to adjust the positions of the upper and lower shaft rolls to the positions corresponding to the maximum correction curvature required; rolling is to roll the TA1 titanium cylinder 2 - 3 circles under the correction curvature; unloading is to gradually remove the load, and then roll the TA1 titanium cylinder multiple times to make the straightness of its cylinder surface ≤ 0.05 mm and the roundness ≤ 0.05 mm.

[0046] Further, in Step 16, ultrasonic impact is used to remove the residual stress on the cylinder surface of the TA1 titanium cylinder. The specific process is as follows: The impact power is 780 - 860 W, the impact frequency is 35 - 45 HZ, the amplitude is 35 - 40 μm, and the impact speed is 0.05 - 0.10 m / min.

[0047] Further, in Step 17, finish machining is performed on the surface of the TA1 titanium cylinder, including two steps of grinding and polishing. Among them, grinding is to grind the cylinder surface of the TA1 titanium cylinder respectively using 40-mesh, 60-mesh, 80-mesh, and 200-mesh grinding wheels, and polishing is to perform mirror machining on the cylinder surface using mirror machining equipment. Finally, the surface roughness Ra of the cylinder surface ≤ 0.8 μm.

[0048] The beneficial effects of the present invention are as follows: Compared with the prior art, a manufacturing method of a high-uniformity and high-grain-size welded titanium cylinder for a cathode roll provided by the present invention has the following advantages: Using TA1 titanium plate as the raw material, it is rolled by a four-roll plate rolling machine, and the narrow-gap laser welding method is adopted. The opening of the TA1 titanium cylinder is welded in a spatial spiral swing mode of the laser beam. This welding process has the characteristics of high welding efficiency, narrow weld and welding heat-affected zone, and fine weld grains. The welded TA1 titanium cylinder is heated at high, medium, and low temperatures, and is forged at high, medium, and low temperatures as a whole to make the TA1 titanium cylinder undergo uniform deformation as a whole. After forging, the TA1 titanium cylinder is heat-treated to ensure that the grains of the TA1 titanium cylinder are uniform and refined as a whole. After heat treatment, the TA1 titanium cylinder is machined and roundness-corrected to make it have excellent straightness and roundness. The ultrasonic impact method is used to remove the residual stress on the surface of the TA1 titanium cylinder, reduce the residual stress of the TA1 titanium cylinder, and prevent the residual stress of the titanium cylinder from being released over time and affecting its dimensional accuracy. In summary, the present invention has the characteristics of high welding efficiency, narrow weld and welding heat-affected zone, uniform and fine grains of the whole TA1 titanium cylinder, and low residual stress, and solves the problem that there is color difference on the roll surface of the cathode roll, and the grains at the weld and the base metal are uneven, resulting in periodic bright bands on the surface of the copper foil produced. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a schematic diagram of the four-roll plate rolling machine in step two of the present invention.

[0050] Figure 2 It is a schematic diagram of the welding process of the narrow-gap laser welding method in step five of the present invention.

[0051] Figure 3 It is a schematic diagram of the high, medium, and low temperature forging process in the present invention.

[0052] Figure 4 It is the grain morphology of the welded titanium cylinder for the cathode roll obtained in Example 1.

[0053] Figure 5 It is the grain morphology of the welded titanium cylinder for the cathode roll obtained in Example 2.

[0054] Figure 6 It is the grain morphology of the welded titanium cylinder for the cathode roll obtained in Example 3.

[0055] Wherein: 1 - upper shaft roll, 2 - lower shaft roll, 3 - left roll, 4 - right roll, 5 - TA1 pure titanium plate, 6 - TA1 titanium cylinder, 7 - TA1 pure titanium welding wire, 8 - groove, 9 - laser beam, 10 - spatial spiral swing mode, 11 - welded TA1 titanium cylinder, 12 - weld, 13 - mold, 14 - upper anvil of the forging press, 15 - lower anvil. DETAILED DESCRIPTION OF THE INVENTION

[0056] The present invention will be further described below through specific embodiments. However, these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention.

[0057] A method for manufacturing a high-uniformity and high-grain-size welded titanium cylinder for a cathode roll, comprising the following steps:

[0058] Step 1: Purchase industrial pure titanium plates made of TA1.

[0059] Step 2: Measure, inspect, and preprocess the incoming TA1 pure titanium plates 5.

[0060] Step 3: Install the TA1 pure titanium plates 5 on a four-roll plate bending machine and perform a rounding operation on them, including centering, unloading, pre-bending, and rolling, and then unload the cylinder.

[0061] Step 4: Machine the groove at the seam of the TA1 titanium cylinder 6.

[0062] Step 5: Perform pre-welding pretreatment on the slit TA1 titanium cylinder 6.

[0063] Step 6: Adopt the narrow-gap laser welding method and, under the protection of an inert protective gas, weld the seam of the TA1 titanium cylinder 6 in a spiral swing mode of the laser beam in space.

[0064] Step 7: After the first layer of welding is completed, clean the weld bead, and then repeat the single-layer single-pass welding until the seam of the TA1 titanium cylinder 6 is filled to form the entire weld seam, complete the welding, and clean the surfaces of the inner and outer weld seams of the TA1 titanium cylinder 6 again.

[0065] Step 8: Apply a high-temperature water glass coating to the surface of the welded TA1 titanium cylinder and then place it in a pit-type high-temperature resistance furnace for the first high-temperature heating.

[0066] Step 9: Take out the welded TA1 titanium cylinder 11 after high-temperature heating, put asbestos on its outside, and at the same time, place an asbestos pad on the surface of the lower anvil 15 of the forging press. Cooperate with the pre-heated die 13, move it to the forging press, and perform the first high-temperature forging on the whole by the upper anvil 14 of the forging press.

[0067] Step 10: Apply a high-temperature water glass coating to the surface of the TA1 titanium cylinder after high-temperature forging and then place it in a pit-type high-temperature resistance furnace for the second medium-temperature heating.

[0068] Step 11: Take out the TA1 titanium cylinder after medium-temperature heating, put asbestos on its outside, and at the same time, place an asbestos pad on the surface of the lower anvil of the forging press. Cooperate with the pre-heated die 13, move it to the forging press, and perform the second medium-temperature forging on the whole by the upper anvil 14 of the forging press.

[0069] Step Twelve: Apply a high-temperature sodium silicate coating to the surface of the TA1 titanium cylinder after medium-temperature forging, and then place it in a pit-type high-temperature resistance furnace for the third low-temperature heating.

[0070] Step Thirteen: Take out the TA1 titanium cylinder after low-temperature heating, put asbestos on its outside, and at the same time place an asbestos pad on the surface of the lower anvil of the forging press. Cooperate with the pre-heated die 13, move it to the forging press, and perform the third low-temperature forging on the whole through the upper anvil 14 of the forging press.

[0071] Step Fourteen: Air-cool the TA1 titanium cylinder after high, medium, and low-temperature forging by the forging press to room temperature, and then perform heat treatment on the TA1 titanium cylinder to refine the grains of the whole TA1 titanium cylinder.

[0072] Step Fifteen: Rough-machine the inner and outer surfaces of the TA1 titanium cylinder after heat treatment so that the roughness Ra of its inner surface is ≤6.2μm and the roughness Ra of its outer surface is ≤4.8μm.

[0073] Step Sixteen: Install the TA1 titanium cylinder on a four-roll plate bender for roundness correction, and then unload the TA1 titanium cylinder after the treatment.

[0074] Step Seventeen: Use the ultrasonic impact method to remove the residual stress on the surface of the TA1 titanium cylinder.

[0075] Step Eighteen: Finish-machine the surface of the TA1 titanium cylinder so that the roughness Ra of its inner surface is ≤3.2μm and the roughness Ra of its outer surface reaches ≤0.8μm.

[0076] The length of the TA1 commercially pure titanium plate in Step One is 8485mm, with an allowable deviation of -25 to 0mm, the width is 800mm, with an allowable deviation of 0 to +20mm, the thickness is 50 to 80mm, the flatness of the plate with the specified width is 8 to 10mm / m, the tensile strength Rm of the plate at room temperature is 300 to 310Mpa, the mass fraction of the plate: the main component Ti≥99.15%, impurity components: Fe≤0.20%, O≤0.18%, C≤0.08%, N≤0.03%, H≤0.015%, the mass fraction of other single impurity elements ≤0.10%, the total ≤0.40%, the surface roughness Ra of the plate is 2.8 to 3.2μm, the manufacturing method of the plate is hot rolling, the supply state is the annealed state, the edges of the plate are flush, without cracks or curled edges, the surface is smooth, without cracks, peeling, oxide scale, or caustic washing marks, and the four corners are right angles.

[0077] The measurement of the TA1 pure titanium plate in Step Two is to measure the actual dimensions of the plate, including length, width, and thickness; the inspection of the TA1 pure titanium plate includes appearance quality inspection, composition inspection, and ultrasonic non-destructive flaw detection; the pretreatment of the TA1 pure titanium plate is to remove the iron filings and debris on the plate to prevent dents or damage to the equipment.

[0078] The four-roll plate bending machine in Step 3 mainly includes four working shaft rolls, all made of 42CrMo, as Figure 1 shown, the upper shaft roll 1, the lower shaft roll 2, the left side roll 3, and the right side roll 4. Among them, the roll body length of the upper shaft roll 1 is 2300 mm, the diameter is 1100 mm, the roll body length of the lower shaft roll 2 is 2120 mm, the diameter is 910 mm, and the roll body lengths of the left side roll 3 and the right side roll 4 are both 1860 mm, and the diameters are both 760 mm.

[0079] The centering operation in Step 3 is to keep the side of the TA1 pure titanium plate 5 parallel to the central axis of the upper shaft roll 1 to avoid phenomena such as deflection and distortion during the rolling process. During centering, the lower shaft roll 2 needs to be slowly lifted to keep the distance between the upper shaft roll 1 and the lower shaft roll 2 at 53 - 58 mm. Then, the right side roll 4 is lifted to the same height as the lower shaft roll 2. Then, the center line of the left side roll 3 is lifted to be between the upper shaft roll 1 and the lower shaft roll 2. The TA1 pure titanium plate 5 is moved into the space between the upper shaft roll 1 and the lower shaft roll 2 until it abuts against the left side roll 3. At this time, the centering operation is completed.

[0080] The unloading operation in Step 3 is to lower the left side roll 3 to the initial height, lift the lower shaft roll 2 until the TA1 pure titanium plate 5 contacts the upper shaft roll 1 and the lower shaft roll 2, rotate the upper shaft roll 1 counterclockwise, and drive the TA1 pure titanium plate 5 to move backward to the right by using the friction force between the surface of the TA1 pure titanium plate 5 and the upper shaft roll 1 and the lower shaft roll 2. When the remaining distance at the left end of the TA1 pure titanium plate 5 is 60 - 95 mm, the upper shaft roll 1 stops rotating.

[0081] The pre-bending operation in Step 3 is to press the TA1 pure titanium plate 5 by the upper shaft roll 1 and the lower shaft roll 2, raise the left side roll 3 to apply force, and make one end of the TA1 pure titanium plate 5 bend. When pre-bending the other end, the TA1 pure titanium plate 5 does not need to be taken out of the equipment. Move the TA1 pure titanium plate 5 to the other end and perform pre-bending in the same way. This operation aims to minimize the length of the remaining straight edge and improve the forming accuracy of the TA1 titanium cylinder.

[0082] The rolling operation in Step 3 is to lower the right side roll 4 to the initial position, adjust the left side roll 3 to the specified position, rotate the upper shaft roll 1, and drive the TA1 pure titanium plate 5 to move through friction to achieve continuous rolling, making the TA1 pure titanium plate 5 undergo continuous bending with equal curvature. When the length of the right edge of the TA1 pure titanium plate 5 is 60 - 95 mm, the upper shaft roll 1 stops rotating, completing the first pass of roll bending. Repeat the above operation until a TA1 titanium cylinder with an outer diameter of 2700 mm is rolled. The allowable dimensional deviation is 0 - +25 mm. The rolling speed of the rolling is 2 - 4 m / min.

[0083] The groove 8 in Step 4 is of the Y type. The Y-type groove 8 is opened from the inner wall of the TA1 titanium cylinder. The root face size of the groove 8 is 4-6 mm, and the single groove angle is 15-20 degrees.

[0084] The pre-welding pretreatment in Step 5 is to first grind the oxide scale on the surface of the groove 8, and then pickle its surface with a mixed solution of hydrofluoric acid and nitric acid. The volume fraction of hydrofluoric acid in the mixed solution of hydrofluoric acid and nitric acid is 4-6%, and the volume fraction of nitric acid is 24-36%. The balance is water. Then rinse with clean water, wipe the surface of the groove with anhydrous ethanol, and dry it with a hair dryer.

[0085] The narrow-gap laser welding method in Step 6 is as Figure 2 shown. Welding starts from the inside of the TA1 titanium cylinder 6. Its laser power is 2500-5500 W, the defocus amount is -10 to +20 mm, its welding speed is 40-80 mm / min, its filler material is TA1 pure titanium welding wire 7, the diameter of TA1 pure titanium welding wire 7 is 2.5-3 mm, the laser beam 9 forms a first included angle with the normal of the plane where the slit of the TA1 titanium cylinder 6 is located, the TA1 pure titanium welding wire 7 forms a second included angle with the plane where the slit of the TA1 titanium cylinder 6 is located, and there is no gap between the incident point of the laser beam 9 and the end of the TA1 pure titanium welding wire 7. The first included angle is 15-20 degrees, and the second included angle is 35-45 degrees.

[0086] The inert protective gas in Step 6 is high-purity argon with a purity of 99.99-99.999%, and the gas flow rate of the protective gas is 18-25 L / min.

[0087] The swing frequency of the spiral swing mode 10 of the laser beam in Step 6 is 150-300 HZ, the swing amplitude is 1-3 mm, and the spiral lift angle is 15-30 degrees.

[0088] The cleaning method used to clean the inner and outer welds 12 of the weld bead and the welded TA1 titanium cylinder 11 in Step 7 is laser cleaning, that is, by irradiating the laser beam on the surface of the weld bead layer. Under the aggregation of laser energy, the huge energy of the beam irradiates on the surface to break the oxides between the weld bead layers, making it instantly peel off from the base material.

[0089] In Step 8, the welded TA1 titanium cylinder 11 is placed in a pit-type high-temperature resistance furnace for heating. Its heating process is to heat at a heating rate of 7 °C / min to 10 °C / min to 540 °C to 570 °C, hold for 20-30 min, then heat at a heating rate of 9 °C / min to 13 °C / min to 830 °C to 860 °C, hold for 30-40 min, and finally heat at a heating rate of 9 °C / min to 13 °C / min to 1050 °C to 1080 °C, hold for 40-50 min.

[0090] The forging press in Step 9 adopts an automatic control forging mode, and the forging process, reduction amount, and reduction rate are preset in advance. The initial forging temperature is 950 - 980 °C, and the final forging temperature is 890 - 920 °C. The welded TA1 titanium cylinder 11 is made into an outer diameter of 2700 mm, with a dimensional tolerance of 0 - +25 mm, a width of 1200 - 1350 mm, a thickness of 32 - 51 mm, a high-temperature forging feeding amount of 250 - 350 mm, a reduction amount of 160 - 240 mm. The forging is carried out along the axis of the welded TA1 titanium cylinder 11. After forging from one end of the TA1 titanium cylinder to the other end, it rotates 15 - 20° and repeats the forging operation until the surface of the welded TA1 titanium cylinder 11 is all subjected to high-temperature forging by the upper anvil 14 of the forging press. After the forging is completed, the TA1 titanium cylinder is cooled to room temperature by air cooling.

[0091] In Step 10, the TA1 titanium cylinder after high-temperature forging is placed in a pit-type high-temperature resistance furnace for heating. The heating process is to heat it to 530 - 560 °C at a heating rate of 7 °C / min - 10 °C / min, hold for 20 - 30 min, and then heat it to 830 - 850 °C at a heating rate of 9 °C / min - 13 °C / min, and hold for 40 - 50 min.

[0092] The forging press in Step 11 adopts an automatic control forging mode, and the forging process, reduction amount, and reduction rate are preset in advance. The initial forging temperature is 735 - 745 °C, and the final forging temperature is 685 - 700 °C. The TA1 titanium cylinder is made into an outer diameter of 2700 mm, with a dimensional tolerance of 0 - +25 mm, a width of 1300 - 1500 mm, a thickness of 25 - 44 mm, a medium-temperature forging feeding amount of 150 - 260 mm, a reduction amount of 100 - 170 mm. The forging is carried out along the circumferential direction of the TA1 titanium cylinder. After forging one circle from the starting point of the TA1 titanium cylinder, the titanium cylinder moves axially by 0 - 20 mm, and repeats the forging operation until the surface of the TA1 titanium cylinder is all subjected to medium-temperature forging by the upper anvil 14 of the forging press. After the forging is completed, the TA1 titanium cylinder is cooled to room temperature by air cooling.

[0093] In Step 12, the TA1 titanium cylinder after medium-temperature forging is placed in a pit-type high-temperature resistance furnace for heating. The heating process is to heat it to 645 - 675 °C at a heating rate of 7 °C / min - 10 °C / min, and hold for 40 - 50 min.

[0094] In Step 13, the forging press adopts an automatic control forging mode, as Figure 3As shown, the forging process, reduction, and reduction rate are preset. The initial forging temperature is 545 - 575°C, and the final forging temperature is 505 - 515°C. The TA1 titanium cylinder is made with an outer diameter of 2700 mm, a dimensional tolerance of 0 - +25 mm, a width of 1400 - 1600 mm, a thickness of 20 - 26 mm, a medium-temperature forging feed of 85 - 165 mm, a reduction of 55 - 100 mm. The forging is carried out along the axis of the TA1 titanium cylinder. After forging from one end of the titanium cylinder to the other end, it is rotated 15 - 20° and the forging operation is repeated until the surface of the TA1 titanium cylinder is all subjected to low-temperature forging by the upper anvil 14 of the forging press. After the forging is completed, the TA1 titanium cylinder is cooled to room temperature by air cooling.

[0095] The high-temperature water glass coating in Step 8, Step 10, and Step 12 is a glass protective lubricant, a glass protective lubricant, and water. The mass ratio of the three raw materials is 4:1:8. During the brushing process, it is ensured that the brushing is carried out unidirectionally from one end of the titanium cylinder to the other end, and the brushing thickness is 0.6 - 1.2 mm.

[0096] The function of adding asbestos to the surface of the titanium cylinder and the lower anvil 15 of the forging press in Step 9, Step 11, and Step 13 is heat preservation. The material of the mold 13 is 42CrMo, with a height of 2000 mm, a dimensional tolerance of 0 - +20 mm, an outer diameter of 2610 mm, a dimensional tolerance of ±1 mm, and an inner diameter of 1500 mm, a dimensional tolerance of 0 - +10 mm. The preheating process of the mold is to put the mold into a pit type resistance furnace and heat it to 500°C - 550°C at a heating rate of 10 - 11°C / min and hold for 30 min.

[0097] The heat treatment of the TA1 titanium cylinder in Step 14 is to put the TA1 titanium cylinder cooled to room temperature into a pit type resistance furnace, set the heat treatment process to heat it to 300 - 350 degrees Celsius at a heating rate of 5 - 8°C / min, then heat it to 550 - 565°C at a heating rate of 7 - 9°C / min, hold for 30 - 40 min, then open the furnace cover, take it out after it cools to room temperature, and then sample and detect its average grain grade.

[0098] The rough machining of the inner and outer surfaces of the heat-treated TA1 titanium cylinder in Step 15 is carried out using a CNC lathe. After fixing the titanium cylinder to the corresponding fixture, the inner and outer surfaces of the TA1 titanium cylinder are respectively turned according to the tool path planned by the program. Among them, different specifications of tools need to be replaced during the machining of the inner and outer surfaces. Finally, the surface roughness of the inner surface Ra ≤ 6.2 μm, and the surface roughness of the outer surface Ra ≤ 4.8 μm. The outer diameter of the TA1 titanium cylinder is 2700 mm, with an allowable deviation of 3 - 5 mm, a width of 1350 - 1580 mm, and a thickness of 13 - 15 mm.

[0099] The roundness correction process of installing the TA1 titanium cylinder on the four-roll plate bending machine in Step 16 mainly includes three steps: loading, rolling, and unloading. Among them, loading is to adjust the position of the shaft roller to the position corresponding to the maximum correction curvature required according to experience. Rolling is to roll the TA1 titanium cylinder for 2 - 3 turns under the correction curvature. Unloading is to gradually remove the load, and then roll the titanium cylinder multiple times to ensure that the straightness of its cylinder surface is ≤0.05 mm and the roundness is ≤0.05 mm.

[0100] The ultrasonic impact in Step 17 is used to remove the residual stress on the surface of the TA1 titanium cylinder. The specific process is as follows: the impact power is 780 - 860 W, the impact frequency is 35 - 45 HZ, the amplitude is 35 - 40 μm, and the impact speed is 0.05 - 0.10 m / min.

[0101] The finish machining of the surface of the TA1 titanium cylinder in Step 18 includes two steps: grinding and polishing. Among them, grinding is to grind the surface of the TA1 titanium cylinder using grinding wheels with 40 mesh, 60 mesh, 80 mesh, and 200 mesh respectively. Polishing is to perform mirror machining on the cylinder surface using mirror machining equipment. Finally, the surface roughness Ra of the cylinder surface is ≤0.8 μm.

[0102] Example 1

[0103] A manufacturing method of a welded titanium cylinder for a cathode roller with a diameter of 2700 mm, a width of 1380 mm, a wall thickness of 13 mm, and an average grain size of 11 grades includes the following steps:

[0104] Step 1: Purchase hot-rolled and annealed TA1 industrial pure titanium.

[0105] Step 2: Measure the actual dimensions of the TA1 plate, with the length, width, and thickness being 8482 mm, 800 mm, and 52 mm respectively. Inspect the appearance quality of the TA1 plate. The edges of the plate are flush and there is no curling. The surface is smooth, without peeling, oxide scale, and caustic washing marks. The four corners are right angles. Detect the composition of the TA1 plate. The main component Ti = 99.35%, and the impurity components are: Fe = 0.16%, O = 0.15%, C = 0.04%, N = 0.022%, H = 0.010%, and the total mass fraction of other single impurity elements is 0.25%. Conduct ultrasonic non-destructive flaw detection on the plate, and there are no defects such as cracks and inclusions. Test the surface roughness Ra of the plate to be 3.1 μm, and remove the iron filings and debris on the plate to prevent pitting or damage to the equipment.

[0106] Step 3: Install the TA1 pure titanium plate on the four-roll plate bending machine and perform a rounding operation, as Figure 1As shown in the figure, first, keep the side of the TA1 pure titanium plate 5 parallel to the central axis of the upper roller (1) to avoid deflection, distortion and other phenomena during the rolling process. During centering, slowly move the lower roller 2 upward so that the distance between the upper and lower rollers 2 is maintained at 54 mm. Then move the right roller 4 upward to the same height as the lower roller 2. Then move the center line of the left roller 3 upward to be between the upper roller 1 and the lower roller 2. Move the TA1 pure titanium plate 5 into the space between the upper roller 1 and the lower roller 2 until it touches the left roller 3. At this time, the centering operation is completed. After that, lower the left roller 3 to its initial height, move the lower roller 2 upward until the TA1 pure titanium plate 5 contacts the upper roller 1 and the lower roller 2. Rotate the upper roller 1 counterclockwise, and use the frictional force between the surface of the TA1 pure titanium plate 5 and the roller to drive the TA1 pure titanium plate 5 to move backward to the right. When the remaining distance at the left end of the TA1 pure titanium plate 5 is 65 mm, stop the rotation of the upper roller 1. Then, the upper roller 1 and the lower roller 2 press the TA1 pure titanium plate 5 tightly, raise the left roller 3 to apply force, and bend one end of the TA1 pure titanium plate 5. When pre-bending the other end, it is not necessary to take out the TA1 pure titanium plate 5 from the equipment. Move the TA1 pure titanium plate 5 to the other end and perform pre-bending in the same way. This operation aims to minimize the length of the remaining straight edge and improve the forming accuracy of the TA1 titanium cylinder. Finally, lower the right roller 4 to its initial position, adjust the left roller 3 to the specified position, and rotate the upper roller 1. Drive the TA1 pure titanium plate 5 to move through the frictional force to achieve continuous rolling, so that the TA1 pure titanium plate 5 undergoes continuous bending with equal curvature. When the length of the right edge of the TA1 pure titanium plate 5 is 65 mm, stop the rotation of the upper roller 1 to complete the first pass of roll bending. Repeat the above operations until the rolling is completed. The outer diameter of the TA1 titanium cylinder is 2700.5 mm, and the rolling speed of the rolled plate is 3 m / min.

[0107] Step 4: Machine a bevel groove at the seam of the TA1 titanium cylinder. Cut a Y-shaped bevel groove 8 from the inner wall of the titanium cylinder. The blunt edge size of the bevel groove 8 is 4 mm, and the single bevel angle is 15 degrees.

[0108] Step 5: Grind the oxide scale on the surface of the bevel groove 8 of the slit TA1 titanium cylinder, and then pickle its surface with a mixed solution of hydrofluoric acid and nitric acid. In the mixed solution of hydrofluoric acid and nitric acid, the volume fraction of hydrofluoric acid is 5%, the volume fraction of nitric acid is 30%, and the balance is water. Then rinse with clean water, wipe the surface of its bevel groove with anhydrous ethanol, and dry it with a hair dryer.

[0109] Step 6: As Figure 2As shown in the figure, the narrow-gap laser welding method is adopted. Under the protection of high-purity argon with a purity of 99.999% and a gas flow rate of 22 L / min, the slit of the TA1 titanium cylinder is welded in a spiral swing mode of the laser beam in space. The swing frequency is 180 HZ, the swing amplitude is 1.5 mm, and the spiral lift angle is 25 degrees. Welding starts from the inside of the TA1 titanium cylinder 6. The laser power is 3800 W, the defocus amount is +5 mm, the welding speed is 55 mm / min, a TA1 pure titanium wire 7 with a diameter of 2.5 mm is used as the filler material, the laser beam 9 forms an angle of 20 degrees with the normal of the plane where the slit of the TA1 titanium cylinder 6 is located, the TA1 pure titanium wire 7 forms an angle of 40 degrees with the plane where the slit of the TA1 titanium cylinder 6 is located, and there is no gap between the incident point of the laser beam 9 and the end of the TA1 pure titanium wire 7.

[0110] Step 7: After each layer of welding is completed, the weld bead is cleaned by the laser cleaning method. When the slit of the TA1 titanium cylinder is filled to form a complete weld, the welding is completed, and the inner and outer weld surfaces of the TA1 titanium cylinder are cleaned again.

[0111] Step 8: Coat the surface of the welded TA1 titanium cylinder with high-temperature water glass prepared by mixing glass protective lubricant, glass protective lubricant and water in a mass ratio of 4:1:8. During the coating process, ensure that it is coated unidirectionally from one end of the titanium cylinder to the other end. The coating thickness is 1.2 mm. After coating, it is placed in a well-type high-temperature resistance furnace for the first high-temperature heating. The heating process is to heat it to 560 °C at a heating rate of 10 °C / min, hold for 22 min, then heat it to 850 °C at a heating rate of 12 °C / min, hold for 32 min, and finally heat it to 1060 °C at a heating rate of 12 °C / min, hold for 42 min.

[0112] Step 9: Place a mold made of 42CrMo, with a height of 2000 mm, an outer diameter of 2610 mm, and an inner diameter of 1500 mm, into a well-type resistance furnace and heat it to 540 °C at a heating rate of 10 °C / min, hold for 30 min. Take out the welded TA1 titanium cylinder after high-temperature heating, put asbestos on its outside, and at the same time place an asbestos pad on the surface of the lower anvil of the forging press. Cooperate with the preheated mold, move it to a forging press in the automatic control forging mode, and perform the first high-temperature forging on the whole through the upper anvil 14 of the forging press. The starting forging temperature is 955 °C, and the final forging temperature is 890 °C. The welded TA1 titanium cylinder 11 is made into an outer diameter of 2701 mm, a width of 1200 mm, a thickness of 32 mm, a high-temperature forging feed of 265 mm, a reduction of 165 mm. The forging is carried out along the axis direction of the welded TA1 titanium cylinder 11. After forging from one end of the titanium cylinder to the other end, rotate 18° and repeat the forging operation until the surface of the welded TA1 titanium cylinder 11 is all subjected to high-temperature forging by the upper anvil (14) of the forging press. After forging is completed, the TA1 titanium cylinder is cooled to room temperature by air cooling.

[0113] Step 10. Apply high-temperature water glass prepared by glass protective lubricant, glass protective lubricant and water in a mass ratio of 4:1:8 on the surface of the TA1 titanium cylinder after high-temperature forging. During the coating process, ensure that it is coated in a single direction from one end of the titanium cylinder to the other end. The coating thickness is 1.0mm. After the coating, put it into a well-type high-temperature resistance furnace for a second medium-temperature heating. The heating process is to heat to 545°C at a heating rate of 10°C / min, keep warm for 22 minutes, and then heat to 845°C at a heating rate of 12°C / min, and keep warm for 42 minutes.

[0114] Step 11. Place the mold made of 42CrMo, with a height of 2000mm, an outer diameter of 2610mm and an inner diameter of 1500mm into a pit-type resistance furnace, heat it to 540℃ at a heating rate of 10℃ / min, and keep it warm for 30 minutes. Take out the welded TA1 titanium cylinder after medium temperature heating, and cover it with asbestos. At the same time, add an asbestos pad to the surface of the lower anvil of the forging press. With the preheated mold, move it to the automatic control forging mode forging press and pass it through the forging press. The upper anvil 14 of the forging press performs a second medium-temperature forging on the entire TA1 titanium tube, with the initial forging temperature being 735°C and the final forging temperature being 685°C. The TA1 titanium tube is made into an outer diameter of 2702mm, a width of 1300mm, and a thickness of 25mm. The medium-temperature forging feed amount is 195mm, and the pressing amount is 100mm. The forging is performed along the TA1 titanium tube in the circumferential direction until the surface of the TA1 titanium tube is subjected to medium-temperature forging by the upper anvil (14) of the forging press. After the forging is completed, the TA1 titanium tube is cooled to room temperature by air cooling.

[0115] Step 12: Apply high-temperature water glass prepared by glass protective lubricant, glass protective lubricant and water in a mass ratio of 4:1:8 on the surface of the TA1 titanium cylinder after medium-temperature forging. During the coating process, ensure that it is coated in a single direction from one end of the titanium cylinder to the other end. The coating thickness is 0.8mm. After the coating, put it into a well-type high-temperature resistance furnace for the third low-temperature heating. The heating process is to heat to 655°C at a heating rate of 10°C / min and keep it warm for 42 minutes.

[0116] Step 13: Place a mold made of 42CrMo, with a height of 2000 mm, an outer diameter of 2610 mm, and an inner diameter of 1500 mm into a pit type resistance furnace, heat it at a heating rate of 10 °C / min to 540 °C, hold for 30 min. Take out the welded TA1 titanium cylinder after low-temperature heating, put asbestos on its outside, and at the same time place an asbestos pad on the surface of the lower anvil of the forging press. Cooperate with the preheated mold, move it to the forging press in the automatic control forging mode, and use the upper anvil 14 of the forging press to perform the third low-temperature forging on the whole. The starting forging temperature is 545 °C, and the final forging temperature is 505 °C. Make the TA1 titanium cylinder into an outer diameter of 2702 mm, a width of 1380 mm, a thickness of 21 mm, a low-temperature forging feed of 85 mm, a reduction of 55 mm. The forging is carried out along the axis direction of the welded TA1 titanium cylinder 11. After forging from one end of the titanium cylinder to the other end, rotate 18° and repeat the forging operation until the surface of the TA1 titanium cylinder is all subjected to low-temperature forging by the upper anvil (14) of the forging press. After the forging is completed, use air cooling to cool the TA1 titanium cylinder to room temperature.

[0117] Step 14: Air-cool the TA1 titanium cylinder after being forged three times at high, medium, and low temperatures by the forging press to room temperature, and then perform heat treatment on the TA1 titanium cylinder to refine the grains of the whole TA1 titanium cylinder. The heat treatment process is to heat it at a heating rate of 8 °C / min to 350 °C, and then heat it at a heating rate of 9 °C / min to 555 °C, hold for 32 min, then open the furnace cover, take it out after it cools to room temperature, and then take samples to detect that its average grain grade is 11, as Figure 4 shown.

[0118] Step 15: Use a CNC lathe. After fixing the titanium cylinder to the corresponding fixture, turn the inner surface and outer surface of the TA1 titanium cylinder respectively according to the feed path planned by the program. Finally, the surface roughness Ra of its inner surface is 6.0 μm, the surface roughness Ra of the outer surface is 4.5 μm, the outer diameter of the TA1 titanium cylinder is 2701 mm, the width is 1380 mm, and the thickness is 14 mm.

[0119] Step 16: Install the TA1 titanium cylinder on a four-roll plate bender for roundness correction. First, adjust the position of the shaft roll to the position corresponding to the maximum correction curvature required according to experience, then roll the TA1 titanium cylinder for 2 circles under the correction curvature, and then gradually remove the load, and then roll the titanium cylinder multiple times. The straightness of its cylinder surface is 0.03 mm, and the roundness is 0.03 mm. After the treatment is completed, unload the TA1 titanium cylinder.

[0120] Step 17: Use the ultrasonic impact method to remove the residual stress on the surface of the TA1 titanium cylinder. Its impact power is 820 W, the impact frequency is 38 HZ, the amplitude is 36 μm, and the impact speed is 0.06 m / min.

[0121] Step Eighteen: Finish machining the surface of the TA1 titanium cylinder. First, grind the surface of the TA1 titanium cylinder with grinding wheels of 40 mesh, 60 mesh, 80 mesh, and 200 mesh respectively, and then perform mirror machining on the surface with a mirror machining device. Finally, the surface roughness Ra of the cylinder is 0.6 μm.

[0122] Example 2

[0123] A manufacturing method of a welded titanium cylinder for a cathode roller with a diameter of 2700 mm, a width of 1450 mm, a wall thickness of 14 mm, and an average grain size of 11.5 grades, comprising the following steps:

[0124] Step One: Purchase hot-rolled and annealed TA1 industrial pure titanium.

[0125] Step Two: Measure the actual dimensions of the TA1 sheet, with the length, width, and thickness being 8483 mm, 809 mm, and 63 mm respectively. Inspect the appearance quality of the TA1 sheet. The edges of the sheet are flush and there is no curling. The surface is smooth, without peeling, oxide scale, or caustic washing marks. The four corners are right angles. Detect the composition of the TA1 sheet. The main component Ti is 99.48%, and the impurity components are: Fe is 0.13%, O is 0.16%, C is 0.04%, N is 0.018%, H is 0.011%, and the total mass fraction of other single impurity elements is 0.26%. Perform ultrasonic non-destructive flaw detection on the sheet, and there are no defects such as cracks or inclusions. Measure the surface roughness Ra of the sheet to be 3.1 μm, and remove the iron filings and debris on the sheet to prevent dents or damage to the equipment.

[0126] Step Three: Install the TA1 pure titanium sheet on a four-roll plate bending machine and perform a curling operation, as Figure 1As shown in the figure, first, keep the side of the TA1 pure titanium plate 5 parallel to the central axis of the upper roller (1) to avoid phenomena such as deflection and distortion during the rolling process. During centering, slowly move the lower roller 2 upward so that the distance between the upper and lower rollers 2 is maintained at 55 mm. Then move the right roller 4 upward to the same height as the lower roller 2. Next, move the center line of the left roller 3 upward between the upper roller 1 and the lower roller 2. Move the TA1 pure titanium plate 5 between the upper roller 1 and the lower roller 2 until it abuts against the left roller 3. At this time, the centering operation is completed. After that, lower the left roller 3 to its initial height, move the lower roller 2 upward until the TA1 pure titanium plate 5 contacts the upper roller 1 and the lower roller 2. Rotate the upper roller 1 counterclockwise, and drive the TA1 pure titanium plate 5 to move backward to the right by using the frictional force between the surface of the TA1 pure titanium plate 5 and the roller. When the remaining distance at the left end of the TA1 pure titanium plate 5 is 74 mm, stop the rotation of the upper roller 1. Then, the upper roller 1 and the lower roller 2 press the TA1 pure titanium plate 5 tightly, raise the left roller 3 to apply force, and bend one end of the TA1 pure titanium plate 5. When pre-bending the other end, it is not necessary to take out the TA1 pure titanium plate 5 from the equipment. Just move the TA1 pure titanium plate 5 to the other end and perform pre-bending in the same way. This operation aims to minimize the length of the remaining straight edge and improve the forming accuracy of the TA1 titanium cylinder. Finally, lower the right roller 4 to its initial position, adjust the left roller 3 to the specified position, and rotate the upper roller 1. Drive the TA1 pure titanium plate 5 to move through frictional force to achieve continuous rolling, making the TA1 pure titanium plate 5 undergo continuous bending with equal curvature. When the length of the right edge of the TA1 pure titanium plate 5 is 74 mm, stop the rotation of the upper roller 1 to complete the first pass of roll bending. Repeat the above operations until the rolling into a circle is completed. The outer diameter of the TA1 titanium cylinder is 2701 mm, and the rolling speed of the rolled plate is 3 m / min.

[0127] Step 4: Machine a bevel at the seam of the TA1 titanium cylinder. Cut a Y-shaped bevel 8 from the inner wall of the titanium cylinder. The root face size of the bevel 8 is 5 mm, and the single bevel angle is 18 degrees.

[0128] Step 5: Grind the oxide scale on the surface of the bevel 8 of the slit TA1 titanium cylinder, and then pickle its surface with a mixed solution of hydrofluoric acid and nitric acid. In the mixed solution of hydrofluoric acid and nitric acid, the volume fraction of hydrofluoric acid is 5%, the volume fraction of nitric acid is 30%, and the balance is water. Then rinse with clean water, wipe the surface of its bevel with anhydrous ethanol, and dry it with a hair dryer.

[0129] Step 6: As Figure 2As shown, the narrow-gap laser welding method is adopted. Under the protection of high-purity argon with a purity of 99.999% and a gas flow rate of 22 L / min, the slit of the TA1 titanium cylinder is welded in a spiral swinging mode 10 of the laser beam in space. The swinging frequency is 220 HZ, the swinging amplitude is 2 mm, and the spiral lift angle is 20 degrees. Welding starts from the inside of the TA1 titanium cylinder 6. Its laser power is 4200 W, the defocus amount is +6 mm, its welding speed is 58 mm / min, and a TA1 pure titanium wire 7 with a diameter of 2.5 mm is used as the filler material. The laser beam 9 forms an angle of 20 degrees with the normal of the plane where the slit of the TA1 titanium cylinder 6 is located, and the TA1 pure titanium wire 7 forms an angle of 40 degrees with the plane where the slit of the TA1 titanium cylinder 6 is located. There is no gap between the incident point of the laser beam 9 and the end of the TA1 pure titanium wire 7.

[0130] Step 7: After each layer of welding is completed, the weld bead is cleaned by the laser cleaning method. When the slit of the TA1 titanium cylinder is filled to form the entire weld seam, the welding is completed, and the inner and outer weld surfaces of the TA1 titanium cylinder are cleaned again.

[0131] Step 8: Coat the surface of the welded TA1 titanium cylinder 11 with high-temperature water glass prepared by mixing glass protective lubricant, glass protective lubricant and water in a mass ratio of 4:1:8. During the coating process, ensure that it is coated unidirectionally from one end of the titanium cylinder to the other end, and the coating thickness is 1.2 mm. After coating, it is placed in a pit-type high-temperature resistance furnace for the first high-temperature heating. Its heating process is to heat at a heating rate of 8 °C / min to 560 °C, hold for 24 min, then heat at a heating rate of 10 °C / min to 850 °C, hold for 34 min, and finally heat at a heating rate of 10 °C / min to 1060 °C, hold for 44 min.

[0132] Step 9: Place a mold made of 42CrMo with a height of 2000 mm, an outer diameter of 2610 mm, and an inner diameter of 1500 mm into a pit-type resistance furnace and heat it to 540 °C at a heating rate of 10 °C / min, hold for 30 min. Take out the welded TA1 titanium cylinder after high-temperature heating, put asbestos on its outside, and at the same time add an asbestos pad on the surface of the lower anvil 15 of the forging press. Cooperate with the preheated mold, move it to the forging press in the automatic control forging mode and perform the first high-temperature forging on the whole through the upper anvil 14 of the forging press. The starting forging temperature is 965 °C, and the final forging temperature is 905 °C. The welded TA1 titanium cylinder 11 is made into an outer diameter of 2701 mm, a width of 1300 mm, a thickness of 38 mm, a high-temperature forging feed of 295 mm, a reduction of 195 mm. The forging is carried out along the axis direction of the welded TA1 titanium cylinder 11. After forging from one end of the titanium cylinder to the other end, rotate 18° and repeat the forging operation until the surface of the welded TA1 titanium cylinder 11 is all subjected to high-temperature forging by the upper anvil (14) of the forging press. After the forging is completed, the TA1 titanium cylinder is cooled to room temperature by air cooling.

[0133] Step 10. Apply high-temperature water glass prepared by glass protective lubricant, glass protective lubricant and water in a mass ratio of 4:1:8 on the surface of the TA1 titanium cylinder after high-temperature forging. During the coating process, ensure that it is coated in a single direction from one end of the titanium cylinder to the other end. The coating thickness is 1.0mm. After the coating, put it into a well-type high-temperature resistance furnace for a second medium-temperature heating. The heating process is to heat to 545°C at a heating rate of 8°C / min, keep warm for 24 minutes, and then heat to 845°C at a heating rate of 10°C / min, and keep warm for 44 minutes.

[0134] Step 11: Place a mold made of 42CrMo, with a height of 2000mm, an outer diameter of 2610mm and an inner diameter of 1500mm into a pit-type resistance furnace, heat it to 540℃ at a heating rate of 10℃ / min, and keep it warm for 30 minutes. Take out the welded TA1 titanium cylinder after medium temperature heating, and cover it with asbestos. At the same time, add an asbestos pad to the surface of the lower anvil 15 of the forging press, and move it to the automatic control forging mode forging press with the preheated mold and forge it through the forging press. The upper anvil 14 of the forging machine performs a second medium-temperature forging on the entire TA1 titanium tube, with the initial forging temperature being 740°C and the final forging temperature being 695°C. The TA1 titanium tube is made into an outer diameter of 2702mm, a width of 1400mm, and a thickness of 28mm. The medium-temperature forging feed amount is 235mm, and the pressing amount is 135mm. The forging is performed along the TA1 titanium tube in the circumferential direction until the surface of the TA1 titanium tube is subjected to medium-temperature forging by the upper anvil (14) of the forging press. After the forging is completed, the TA1 titanium tube is cooled to room temperature by air cooling.

[0135] Step 12: Apply high-temperature water glass prepared by glass protective lubricant, glass protective lubricant and water in a mass ratio of 4:1:8 on the surface of the TA1 titanium cylinder after medium-temperature forging. During the coating process, ensure that it is coated in a single direction from one end of the titanium cylinder to the other end. The coating thickness is 0.8mm. After the coating, put it into a well-type high-temperature resistance furnace for the third low-temperature heating. The heating process is to heat to 655°C at a heating rate of 8°C / min and keep it warm for 44 minutes.

[0136] Step 13: Place a mold made of 42CrMo, with a height of 2000 mm, an outer diameter of 2610 mm, and an inner diameter of 1500 mm into a pit type resistance furnace, heat it at a heating rate of 10 °C / min to 540 °C, hold for 30 min. Take out the welded TA1 titanium cylinder after low-temperature heating, put asbestos on its outside, and at the same time place an asbestos pad on the surface of the lower anvil 15 of the forging press. Cooperate with the pre-heated mold, move it to the forging press with automatic control forging mode, and use the upper anvil 14 of the forging press to perform the third low-temperature forging on the whole. The starting forging temperature is 555 °C, the final forging temperature is 510 °C. Make the TA1 titanium cylinder into an outer diameter of 2702 mm, a width of 1450 mm, a thickness of 23 mm, a low-temperature forging feeding amount of 125 mm, a reduction amount of 75 mm. The forging is carried out along the axis direction of the welded TA1 titanium cylinder 11. After forging from one end of the titanium cylinder to the other end, rotate 18° and repeat the forging operation until the surface of the TA1 titanium cylinder is all subjected to low-temperature forging by the upper anvil (14) of the forging press. After the forging is completed, cool the TA1 titanium cylinder to room temperature by air cooling.

[0137] Step 14: Air-cool the TA1 titanium cylinder, which has been subjected to three high, medium, and low-temperature forgings by the forging press, to room temperature. Then perform heat treatment on the TA1 titanium cylinder to refine the overall grains of the TA1 titanium cylinder. The heat treatment process is to heat it to 350 °C at a heating rate of 7 °C / min, and then heat it to 555 °C at a heating rate of 8 °C / min. After holding for 34 min, open the furnace lid. After it cools to room temperature, take it out. Then sample and detect that its average grain grade is 11.5, as Figure 5 shown.

[0138] Step 15: Use a CNC lathe to fix the titanium cylinder to the corresponding fixture and then perform turning on the inner and outer surfaces of the TA1 titanium cylinder according to the tool path planned by the program. Finally, the surface roughness Ra of its inner surface is 5.8 μm, the surface roughness Ra of its outer surface is 4.2 μm. The outer diameter of the TA1 titanium cylinder is 2702 mm, the width is 1450 mm, and the thickness is 14 mm.

[0139] Step 16: Install the TA1 titanium cylinder on a four-roll plate bending machine for roundness correction. First, adjust the position of the shaft roll to the position corresponding to the maximum correction curvature required according to experience. Then roll the TA1 titanium cylinder under the correction curvature for 3 circles, and then gradually unload the load. Then perform multiple rollings on the titanium cylinder. Its cylinder surface straightness is 0.02 mm, and the roundness is 0.02 mm. After the treatment is completed, unload the TA1 titanium cylinder.

[0140] Step 17: Use the ultrasonic impact method to remove the residual stress on the surface of the TA1 titanium cylinder. Its impact power is 825 W, the impact frequency is 40 HZ, the amplitude is 37 μm, and the impact speed is 0.07 m / min.

[0141] Step XVIII: Finish machining the surface of the TA1 titanium cylinder. First, grind the surface of the TA1 titanium cylinder with grinding wheels of 40 mesh, 60 mesh, 80 mesh, and 200 mesh respectively, and then use a mirror machining device to perform mirror machining on the surface. Finally, the surface roughness Ra = 0.6 μm.

[0142] Example 3

[0143] A manufacturing method of a welded titanium cylinder for a cathode roller with a diameter of 2700 mm, a width of 1550 mm, a wall thickness of 14.5 mm, and an average grain size of 11 grades, comprising the following steps:

[0144] Step I: Purchase hot-rolled and annealed TA1 industrial pure titanium;

[0145] Step II: Measure the actual dimensions of the TA1 sheet, with the length, width, and thickness being 8484 mm, 800 mm, and 77 mm respectively. Inspect the appearance quality of the TA1 sheet. The edges of the sheet are flat and there is no curling. The surface is smooth, without peeling, oxide scale, or alkaline washing marks. The four corners are right angles. Detect the composition of the TA1 sheet. The main component Ti = 99.50%, and the impurity components are: Fe = 0.12%, O = 0.11%, C = 0.03%, N = 0.013%, H = 0.009%, and the total mass fraction of other single impurity elements is 0.21%. Conduct ultrasonic non-destructive flaw detection on the sheet, and there are no defects such as cracks or inclusions. Measure the surface roughness Ra of the sheet to be 3.0 μm, and remove the iron filings and debris on the sheet to prevent dents or damage to the equipment;

[0146] Step III: Install the TA1 pure titanium sheet on a four-roll plate bending machine and perform the rounding operation, as Figure 1As shown in the figure, first, keep the side of the TA1 pure titanium plate 5 parallel to the central axis of the upper shaft roller (1) to avoid phenomena such as deflection and distortion during the rolling process. During centering, slowly move the lower shaft roller 2 upward so that the distance between the upper and lower shaft rollers 2 is maintained at 58 mm. Then move the right roller 4 upward to the same height as the lower shaft roller 2. Next, move the center line of the left roller 3 upward between the upper shaft roller 1 and the lower shaft roller 2. Move the TA1 pure titanium plate 5 into the space between the upper shaft roller 1 and the lower shaft roller 2 until it touches the left roller 3. At this time, the centering operation is completed. After that, lower the left roller 3 to its initial height, move the lower shaft roller 2 upward until the TA1 pure titanium plate 5 contacts the upper shaft roller 1 and the lower shaft roller 2. Rotate the upper shaft roller 1 counterclockwise, and use the friction between the surface of the TA1 pure titanium plate 5 and the shaft roller to drive the TA1 pure titanium plate 5 to move backward to the right. When the remaining distance at the left end of the TA1 pure titanium plate 5 is 93 mm, stop the rotation of the upper shaft roller 1. Then, the upper shaft roller 1 and the lower shaft roller 2 press the TA1 pure titanium plate 5 tightly, raise the left roller 3 to apply force, and bend one end of the TA1 pure titanium plate 5. When pre-bending the other end, the TA1 pure titanium plate 5 does not need to be taken out of the equipment. Move the TA1 pure titanium plate 5 to the other end and perform pre-bending in the same way. This operation aims to minimize the length of the remaining straight edge and improve the forming accuracy of the TA1 titanium cylinder. Finally, lower the right roller 4 to its initial position, adjust the left roller 3 to the specified position, and rotate the upper shaft roller 1. Drive the TA1 pure titanium plate 5 to move through friction to achieve continuous rolling, making the TA1 pure titanium plate 5 undergo continuous bending with equal curvature. When the length of the right edge of the TA1 pure titanium plate 5 is 93 mm, stop the rotation of the upper shaft roller 1 to complete the first pass of roll bending. Repeat the above operations until the rolling into a circle is completed. The outer diameter of the TA1 titanium cylinder is 2701 mm, and the rolling speed of the rolled plate is 2 m / min.

[0147] Step 4: Machine a bevel at the seam of the TA1 titanium cylinder. Cut a Y-shaped bevel 8 from the inner wall of the titanium cylinder. The root face size of the bevel 8 is 6 mm, and the single bevel angle is 20 degrees.

[0148] Step 5: Grind the oxide scale on the surface of the bevel 8 of the slit TA1 titanium cylinder, and then pickle its surface with a mixed solution of hydrofluoric acid and nitric acid. In the mixed solution of hydrofluoric acid and nitric acid, the volume fraction of hydrofluoric acid is 5%, the volume fraction of nitric acid is 30%, and the balance is water. Then rinse with clean water, wipe the surface of its bevel with anhydrous ethanol, and dry it with a hair dryer.

[0149] Step 6: As Figure 2As shown in the figure, the narrow-gap laser welding method is adopted. Under the protection of high-purity argon with a purity of 99.999% and a gas flow rate of 22 L / min, the slit of the TA1 titanium cylinder is welded in a spiral swing mode of the laser beam in space. The swing frequency is 280 HZ, the swing amplitude is 2.5 mm, and the spiral lift angle is 20 degrees. Welding starts from the inside of the TA1 titanium cylinder 6. The laser power is 4500 W, the defocus amount is +6 mm, the welding speed is 60 mm / min, and a TA1 pure titanium wire 7 with a diameter of 2.5 mm is used as the filler material. The laser beam 9 forms an angle of 20 degrees with the normal of the plane where the slit of the TA1 titanium cylinder 6 is located, and the TA1 pure titanium wire 7 forms an angle of 40 degrees with the plane where the slit of the TA1 titanium cylinder 6 is located. There is no gap between the incident point of the laser beam 9 and the end of the TA1 pure titanium wire 7.

[0150] Step 7: After each layer of welding is completed, the weld bead is cleaned by laser cleaning method. When the slit of the TA1 titanium cylinder is filled to form an entire weld seam, the welding is completed, and the inner and outer weld surfaces of the TA1 titanium cylinder are cleaned again.

[0151] Step 8: Coat the surface of the welded TA1 titanium cylinder 11 with high-temperature sodium silicate prepared by mixing glass protective lubricant, glass protective lubricant and water in a mass ratio of 4:1:8. During the coating process, ensure that it is coated unidirectionally from one end of the titanium cylinder to the other end, and the coating thickness is 1.2 mm. After coating, it is put into a pit-type high-temperature resistance furnace for the first high-temperature heating. The heating process is to heat it to 560 °C at a heating rate of 7 °C / min, hold for 28 min, then heat it to 850 °C at a heating rate of 9 °C / min, hold for 38 min, and finally heat it to 1060 °C at a heating rate of 9 °C / min, hold for 48 min.

[0152] Step 9: Put a mold made of 42CrMo, with a height of 2000 mm, an outer diameter of 2610 mm, and an inner diameter of 1500 mm into a pit-type resistance furnace, heat it to 540 °C at a heating rate of 10 °C / min, and hold for 30 min. Take out the welded TA1 titanium cylinder after high-temperature heating, put asbestos on its outside, and at the same time put an asbestos pad on the surface of the lower anvil 15 of the forging press. Cooperate with the preheated mold, move it to the forging press in the automatic control forging mode, and perform the first high-temperature forging on the whole by the upper anvil 14 of the forging press. The starting forging temperature is 980 °C, and the final forging temperature is 920 °C. The welded TA1 titanium cylinder 11 is made into an outer diameter of 2701 mm, a width of 1400 mm, a thickness of 41 mm, a high-temperature forging feed of 345 mm, a reduction of 235 mm. The forging is carried out along the axis direction of the welded TA1 titanium cylinder 11. After forging from one end of the titanium cylinder to the other end, rotate 18° and repeat the forging operation until the surface of the welded TA1 titanium cylinder 11 is all subjected to high-temperature forging by the upper anvil (14) of the forging press. After the forging is completed, the TA1 titanium cylinder is cooled to room temperature by air cooling.

[0153] Step Ten: Coat the surface of the TA1 titanium cylinder after high-temperature forging with high-temperature water glass prepared by mixing glass protective lubricant, glass protective lubricant and water in a mass ratio of 4:1:8. During the coating process, ensure that the coating is applied unidirectionally from one end of the titanium cylinder to the other end, with a coating thickness of 1.0 mm. After coating, place it in a well-type high-temperature resistance furnace for the second medium-temperature heating. The heating process is to heat it to 545°C at a heating rate of 7°C / min, hold for 28 min, and then heat it to 845°C at a heating rate of 9°C / min and hold for 48 min.

[0154] Step Eleven: Place a mold made of 42CrMo, with a height of 2000 mm, an outer diameter of 2610 mm, and an inner diameter of 1500 mm, into a well-type resistance furnace and heat it to 540°C at a heating rate of 10°C / min, then hold for 30 min. Take out the welded TA1 titanium cylinder after medium-temperature heating, wrap asbestos around its outside, and at the same time place an asbestos pad on the surface of the lower anvil 15 of the forging press. Cooperate with the pre-heated mold, move it to the forging press in the automatic control forging mode, and use the upper anvil 14 of the forging press to perform the second medium-temperature forging on the whole. The initial forging temperature is 745°C, and the final forging temperature is 700°C. The welded TA1 titanium cylinder 11 is made into an outer diameter of 2702 mm, a width of 1500 mm, a thickness of 30 mm, a medium-temperature forging feed of 260 mm, a reduction of 170 mm. The medium-temperature forging is carried out circumferentially along the TA1 titanium cylinder. After forging one circle from the starting point of the TA1 titanium cylinder, the TA1 titanium cylinder moves 10 mm axially, and repeat the forging operation until the surface of the welded TA1 titanium cylinder 11 is all subjected to medium-temperature forging by the upper anvil (14) of the forging press. After forging is completed, cool the TA1 titanium cylinder to room temperature by air cooling.

[0155] Step Twelve: Coat the surface of the TA1 titanium cylinder after medium-temperature forging with high-temperature water glass prepared by mixing glass protective lubricant, glass protective lubricant and water in a mass ratio of 4:1:8. During the coating process, ensure that the coating is applied unidirectionally from one end of the titanium cylinder to the other end, with a coating thickness of 0.8 mm. After coating, place it in a well-type high-temperature resistance furnace for the third low-temperature heating. The heating process is to heat it to 655°C at a heating rate of 7°C / min and hold for 48 min.

[0156] Step 13: Place a mold made of 42CrMo, with a height of 2000 mm, an outer diameter of 2610 mm, and an inner diameter of 1500 mm, into a pit-type resistance furnace. Heat it at a heating rate of 10 °C / min to 540 °C, hold for 30 min. Take out the welded TA1 titanium cylinder after low-temperature heating, and put asbestos on its outside. At the same time, place an asbestos pad on the surface of the lower anvil 15 of the forging press. Cooperate with the pre-heated mold, move it to the forging press in the automatic control forging mode, and perform the third low-temperature forging on the whole through the upper anvil 14 of the forging press. The starting forging temperature is 570 °C, and the final forging temperature is 515 °C. Make the welded TA1 titanium cylinder 11 into an outer diameter of 2702 mm, a width of 1550 mm, a thickness of 24 mm, a low-temperature forging feed of 165 mm, a reduction of 100 mm. The forging is carried out along the axis direction of the welded TA1 titanium cylinder 11. After forging from one end of the titanium cylinder to the other end, rotate 18° and repeat the forging operation until the surface of the welded TA1 titanium cylinder 11 is all subjected to low-temperature forging by the upper anvil (14) of the forging press. After the forging is completed, cool the TA1 titanium cylinder to room temperature by air cooling.

[0157] Step 14: Air-cool the TA1 titanium cylinder that has been subjected to three high, medium, and low-temperature forgings by the forging press to room temperature. Then perform heat treatment on the TA1 titanium cylinder to refine the grains of the whole TA1 titanium cylinder. The heat treatment process is to heat it to 350 degrees Celsius at a heating rate of 6 °C / min, and then heat it to 555 °C at a heating rate of 7 °C / min. After holding for 336 min, open the furnace lid. After it cools to room temperature, take it out. Then sample and detect that its average grain grade is 11, as Figure 6 shown.

[0158] Step 15: Use a CNC lathe. After fixing the titanium cylinder to the corresponding fixture, perform turning on the inner surface and outer surface of the TA1 titanium cylinder respectively according to the tool path planned by the program. Finally, the surface roughness Ra of its inner surface is 5.9 μm, and the surface roughness Ra of the outer surface is 4.3 μm. The outer diameter of the TA1 titanium cylinder is 2702 mm, the width is 1550 mm, and the thickness is 15 mm.

[0159] Step 16: Install the TA1 titanium cylinder on a four-roll plate bender for roundness correction. First, adjust the position of the shaft roll to the position corresponding to the maximum correction curvature required according to experience. Then roll the TA1 titanium cylinder under the correction curvature for 3 circles, and then gradually remove the load. Then perform multiple rolls on the titanium cylinder. Its cylinder surface straightness is 0.04 mm, and the roundness is 0.03 mm. After the treatment is completed, unload the TA1 titanium cylinder.

[0160] Step 17: Use the ultrasonic impact method to remove the residual stress on the surface of the TA1 titanium cylinder. Its impact power is 835 W, the impact frequency is 44 HZ, the amplitude is 39 μm, and the impact speed is 0.09 m / min.

[0161] Step Eighteen: Finish machining the surface of the TA1 titanium cylinder. First, grind the surface of the TA1 titanium cylinder with grinding wheels of 40 mesh, 60 mesh, 80 mesh, and 200 mesh respectively, and then use mirror machining equipment to perform mirror machining on the surface. Finally, the surface roughness Ra = 0.6μm.

[0162] The above embodiments are only used to illustrate the present invention and are not intended to limit the present invention. Those of ordinary skill in the relevant technical field can also make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions also belong to the scope of the present invention. The patent protection scope of the present invention shall be defined by the claims.

Claims

1. A manufacturing method of a welded titanium cylinder with high uniformity and high crystal grain size for a cathode roller, characterized in that, The production method comprises the following steps: Step 1: Measure, test and pre-treat the incoming TA1 pure titanium plate; Step 2: Install the TA1 pure titanium plate on a four-roller plate rolling machine, perform rolling operations on it, including centering, stripping, pre-bending and rolling, to obtain a TA1 titanium cylinder, and then remove the cylinder; Step 3: Bevel the TA1 titanium cylinder at the seam; Step 4: Pre-weld the TA1 titanium cylinder with seams; Step 5: Using narrow gap laser welding method, under the protection of inert protective gas, the laser beam is used to weld the seam of the TA1 titanium cylinder in a spatial spiral swing mode; Step 6: After the first layer of welding is completed, clean the weld bead, and then repeat the single-layer single-pass welding until the TA1 titanium tube seam is filled to form a whole weld seam, and the welding is completed. The inner and outer weld seam surfaces of the TA1 titanium tube are cleaned again to obtain the welded TA1 titanium tube; Step 7: Apply a high-temperature water glass coating on the surface of the welded TA1 titanium cylinder, and place it in a pit-type high-temperature resistance furnace for the first high-temperature heating; the heating process is to heat it to 540°C~570°C at a heating rate of 7°C / min~10°C / min, keep it warm for 20~30min, then heat it to 830°C~860°C at a heating rate of 9°C / min~13°C / min, keep it warm for 30~40min, and finally heat it to 1050°C~1080°C at a heating rate of 9°C / min~13°C / min, and keep it warm for 40~50min; Step 8: Take out the welded TA1 titanium cylinder after high-temperature heating, and cover it with asbestos. At the same time, add an asbestos pad on the surface of the lower anvil of the forging press. With the preheated die, move it to the forging press and perform the first high-temperature forging on the whole through the upper anvil of the forging press; the initial forging temperature is 950-980°C, and the final forging temperature is 890-920°C; Step nine, apply a high-temperature water glass coating on the surface of the TA1 titanium cylinder after high-temperature forging, and place it in a pit-type high-temperature resistance furnace for a second medium-temperature heating; the heating process is to heat it to 530°C~560°C at a heating rate of 7°C / min~10°C / min, keep it warm for 20~30min, and then heat it to 830°C~850°C at a heating rate of 9°C / min~13°C / min, and keep it warm for 40~50min; Step 10: Take out the TA1 titanium cylinder after medium temperature heating, and cover it with asbestos. At the same time, add an asbestos pad on the surface of the lower anvil of the forging press, and move it to the forging press with the preheated mold and perform a second medium temperature forging on the upper anvil of the forging press; the initial forging temperature is 735-745°C, and the final forging temperature is 685-700°C; Step 11: Apply a high-temperature water glass coating on the surface of the TA1 titanium cylinder after medium-temperature forging, and place it in a pit-type high-temperature resistance furnace for a third low-temperature heating; the heating process is to heat to 645°C to 675°C at a heating rate of 7°C / min to 10°C / min, and keep warm for 40 to 50 minutes; Step 12: Take out the TA1 titanium cylinder after low-temperature heating, and cover it with asbestos. At the same time, add an asbestos pad on the surface of the lower anvil of the forging press. With the preheated die, move it to the forging press and perform the third low-temperature forging on the whole through the upper anvil of the forging press; the initial forging temperature is 545-575°C, and the final forging temperature is 505-515°C; Step 13: air-cool the TA1 titanium cylinder after three times of high, medium and low temperature forging by the forging press to room temperature, and then heat-treat the TA1 titanium cylinder to refine the grain of the entire TA1 titanium cylinder; Step 14: Rough-process the inner and outer surfaces of the heat-treated TA1 titanium cylinder to make the inner surface roughness Ra≤6.2μm and the outer surface roughness Ra≤4.8μm; Step 15: Install the surface treated TA1 titanium cylinder onto a four-roller plate rolling machine for rounding treatment, and remove the TA1 titanium cylinder after the treatment is completed; Step 16: Use ultrasonic impact method to remove residual stress on the surface of TA1 titanium cylinder; Step 17: Finish the surface of the TA1 titanium cylinder so that its inner surface roughness Ra≤3.2μm and its outer surface roughness Ra≤0.8μm.

2. The manufacturing method of a welded titanium cylinder with high uniformity and high crystal grain size for a cathode roll according to claim 1, characterized in that: In the step 1, the unevenness of the width of the TA1 pure titanium plate is 8-10 mm / m, and the tensile strength of the plate at room temperature is Rm=300-310 MPa; the mass fraction of the main components of the plate: Ti≥99.15%, impurity components: Fe≤0.20%, O≤0.18%, C≤0.08%, N≤0.03%, H≤0.015%, the mass fraction of other single impurity elements ≤0.10%, and the total ≤0.40%; the surface roughness of the plate Ra=2.8-3.2 μm; the measurement of the TA1 pure titanium plate is to measure the actual size of the plate, including length, width, and thickness; the inspection of the TA1 pure titanium plate includes appearance quality inspection, component inspection, and ultrasonic non-destructive testing; the pretreatment of the TA1 pure titanium plate is to remove iron filings and debris on the plate to prevent pitting or damage to the equipment.

3. The manufacturing method of a welded titanium cylinder with high uniformity and high crystal grain size for a cathode roller as described in claim 1, characterized in that: In the step 2, the four-roller plate rolling machine mainly comprises four working shaft rollers, namely an upper shaft roller (1), a lower shaft roller (2), a left roller (3), and a right roller (4); the material of the four working shaft rollers is 42CrMo; During the centering operation, the lower shaft roller (2) is slowly moved upwards so that the spacing between the upper and lower shaft rollers is maintained at 53 to 58 mm, and then the right roller (4) is moved upwards to the same height as the lower shaft roller (2), and then the center line of the left roller (3) is moved upwards to between the upper shaft roller (1) and the lower shaft roller (2), and the TA1 pure titanium plate (5) is moved between the upper shaft roller (1) and the lower shaft roller (2) until it contacts the left roller (3), at which point the centering operation is completed; During the material discharging operation, lower the left roller (3) to the initial height, raise the lower shaft roller (2) until the TA1 pure titanium plate (5) contacts the upper shaft roller (1) and the lower shaft roller (2), rotate the upper shaft roller (1) counterclockwise, and drive the TA1 pure titanium plate (5) to move backward to the right by the friction force between the surface of the TA1 pure titanium plate (5) and the upper shaft roller (1) and the lower shaft roller (2). When the remaining distance at the left end of the TA1 pure titanium plate (5) is 60 - 95 mm, stop rotating the upper shaft roller (1) to complete the material discharging; During the pre-bending operation, the upper shaft roller (1) and the lower shaft roller (2) clamp the TA1 pure titanium plate (5), raise the left roller (3) to apply force to bend one end of the TA1 pure titanium plate (5). When pre-bending the other end, it is not necessary to take out the TA1 pure titanium plate (5) from the equipment. Move the TA1 pure titanium plate (5) to the other end and perform pre-bending in the same way; During the rolling operation, lower the right roller (4) to the initial position, adjust the left roller (3) to the specified position, rotate the upper shaft roller (1), and drive the TA1 pure titanium plate (5) to move through the friction force to achieve continuous rolling, making the TA1 pure titanium plate (5) undergo continuous bending with equal curvature. When the length of the right edge of the TA1 pure titanium plate (5) is 60 - 95 mm, stop rotating the upper shaft roller (1) to complete the first pass of roll bending. Repeat the above operation until the rolling is completed to obtain the TA1 titanium cylinder (6). The rolling speed of the rolled plate is 2 - 4 m / min.

4. The manufacturing method of a high-uniformity and high-grain-size welded titanium cylinder for a cathode roll as described in claim 1, wherein: In step three, the type of the groove (8) is Y-shaped. A Y-shaped groove is opened from the inner wall of the TA1 titanium cylinder (6). The root face size of the groove (8) is 4 - 6 mm, and the single groove angle is 15 - 20 degrees.

5. The manufacturing method of a highly uniform and high crystal grain size welded titanium cylinder for a cathode roll as described in claim 1, characterized in that: In step four, the pre-welding pretreatment is to first grind the oxide scale on the surface of the groove (8), and then successively perform pickling, rinsing with clean water, wiping with anhydrous ethanol, and drying on its surface with a mixed solution of hydrofluoric acid and nitric acid; in the mixed solution of hydrofluoric acid and nitric acid, the volume fraction of hydrofluoric acid is 4 - 6%, the volume fraction of nitric acid is 24 - 36%, and the balance is water.

6. The manufacturing method of a high-uniformity and high-crystal-grain-size welded titanium cylinder for a cathode roll as described in claim 1, characterized in that: In step five, the narrow-gap laser welding method is to start welding from the inside of the TA1 titanium cylinder (6). Its laser power is 2500 - 5500 W, the defocus amount is -10 - +20 mm, its welding speed is 40 - 80 mm / min, its filler material is a TA1 pure titanium wire (7) with a diameter of 2.5 - 3 mm. The laser beam (9) forms a first included angle with the normal of the plane where the slit of the TA1 titanium cylinder (6) is located, and the TA1 pure titanium wire (7) forms a second included angle with the plane where the slit of the TA1 titanium cylinder (6) is located. There is no gap between the incident point of the laser beam (9) and the end of the TA1 pure titanium wire (7). The first included angle is 15 - 20 degrees, and the second included angle is 35 - 45 degrees.

7. The manufacturing method of a high-uniformity and high-grain-size welded titanium cylinder for a cathode roll according to claim 1, characterized in that: In step five, the inert protective gas is high-purity argon with a purity of 99.99 - 99.999%. The gas flow rate of the inert protective gas is 18 - 25 L / min; the swing frequency of the spiral swing mode (10) of the laser beam in space is 150 - 300 HZ, the swing amplitude is 1 - 3 mm, and the spiral lift angle is 15 - 30 degrees.

8. The manufacturing method of a high-uniformity and high-grain-size welded titanium cylinder for a cathode roll according to claim 1, characterized in that: In Step 6, the cleaning method for cleaning the weld bead and the surfaces of the internal and external welds (12) of the TA1 titanium cylinder (11) after welding is laser cleaning. By irradiating the laser beam on the surface of the weld bead layer, under the aggregation of laser energy, the huge energy of the beam irradiates on the surface to break the oxides between the weld layers, causing them to peel off from the base material instantaneously.

9. The manufacturing method of a high-uniformity and high-grain-size welded titanium cylinder for a cathode roll as described in claim 1, characterized in that: In Step 8, the forging press adopts an automatic control forging mode to form the welded TA1 titanium cylinder (11) into an outer diameter of 2700 mm, with a dimensional tolerance of 0 to +25 mm, a width of 1200 to 1350 mm, and a thickness of 32 to 51 mm; the feeding amount for hot forging is 250 to 350 mm, the reduction amount is 160 to 240 mm, and the hot forging is carried out along the axis of the welded TA1 titanium cylinder (11). After forging from one end of the welded TA1 titanium cylinder (11) to the other end, it rotates 15 to 20° and repeats the forging operation until the surface of the welded TA1 titanium cylinder (11) is all hot forged by the upper anvil (14) of the forging press. After the forging is completed, the welded TA1 titanium cylinder (11) is cooled to room temperature by air cooling.

10. The manufacturing method of a welded titanium cylinder with high uniformity and high crystal grain size for a cathode roll according to claim 1, characterized in that: In Step 10, the forging press adopts an automatic control forging mode; the TA1 titanium cylinder is formed into an outer diameter of 2700 mm, with a dimensional tolerance of 0 to +25 mm, a width of 1300 to 1500 mm, and a thickness of 25 to 44 mm; the feeding amount for medium-temperature forging is 150 to 260 mm, the reduction amount is 100 to 170 mm, and the medium-temperature forging is carried out circumferentially along the TA1 titanium cylinder. After forging one circle from the starting point of the TA1 titanium cylinder, the TA1 titanium cylinder moves axially by 0 to 20 mm and repeats the forging operation until the surface of the TA1 titanium cylinder is all medium-temperature forged by the upper anvil (14) of the forging press. After the forging is completed, the TA1 titanium cylinder is cooled to room temperature by air cooling.

11. The manufacturing method of a welded titanium cylinder with high uniformity and high grain size for a cathode roll according to claim 1, characterized in that: In Step 12, the forging press adopts an automatic control forging mode to form the TA1 titanium cylinder into an outer diameter of 2700 mm, with a dimensional tolerance of 0 to +25 mm, a width of 1400 to 1600 mm, and a thickness of 20 to 26 mm. The feeding amount for low-temperature forging is 85 to 165 mm, the reduction amount is 55 to 100 mm, and the low-temperature forging is carried out along the axis of the TA1 titanium cylinder. After forging from one end of the TA1 titanium cylinder to the other end, it rotates 15 to 20° and repeats the forging operation until the surface of the TA1 titanium cylinder is all low-temperature forged by the upper anvil (14) of the forging press. After the forging is completed, the TA1 titanium cylinder is cooled to room temperature by air cooling.

12. The manufacturing method of a welded titanium cylinder with high uniformity and high crystal grain size for a cathode roller as described in claim 1, characterized in that: In Steps 7, 9, and 11, the high-temperature water glass coating is composed of glass protective lubricant, glass protective lubricant, and water. The mass ratio of glass protective lubricant, glass protective lubricant, and water is 4:1:

8. During the brushing process, it is ensured to brush in one direction from one end of the TA1 titanium cylinder to the other end, and the brushing thickness is 0.6 to 1.2 mm.

13. The manufacturing method of a high-uniformity and high-grain-size welded titanium cylinder for a cathode roller as claimed in claim 1, characterized in that: In Step 8, Step 10, and Step 12, the material of the mold (13) is 42CrMo. The preheating process of the mold (13) is to place the mold (13) in a pit-type resistance furnace and heat it at a heating rate of 10 - 11 °C / min to 500 - 550 °C, and hold for 30 min.

14. The manufacturing method of a welded titanium cylinder with high uniformity and high crystal grain size for a cathode roll according to claim 1, characterized in that: In Step 13, the heat treatment of the TA1 titanium cylinder is as follows: Place the TA1 titanium cylinder cooled to room temperature in a pit-type resistance furnace. Set the heat treatment process to heat it at a heating rate of 5 - 8 °C / min to 300 - 350 °C, and then heat it at a heating rate of 7 - 9 °C / min to 550 - 565 °C. After holding for 30 - 40 min, open the furnace lid. After it cools to room temperature, take it out, and then sample and detect its average grain grade.

15. The manufacturing method of a highly uniform and high crystal grain size welded titanium cylinder for a cathode roll as described in claim 1, characterized in that: In Step 14, rough machining is performed on the inner and outer surfaces of the heat-treated TA1 titanium cylinder. When machining, a CNC lathe is used. After fixing the TA1 titanium cylinder to the corresponding fixture, turn the inner and outer surfaces of the TA1 titanium cylinder respectively according to the feed path planned by the program. Among them, different specifications of tools need to be replaced when machining the inner and outer surfaces. Finally, the surface roughness Ra of the inner surface ≤ 6.2 μm, and the surface roughness Ra of the outer surface ≤ 4.8 μm.

16. The manufacturing method of a high-uniformity and high-grain-size welded titanium cylinder for a cathode roll according to claim 1, wherein: In Step 15, installing the TA1 titanium cylinder on a four-roll plate bender for roundness correction mainly includes three steps: loading, rolling, and unloading. Among them, loading is to adjust the positions of the upper shaft roll (1) and the lower shaft roll (2) to the positions corresponding to the maximum correction curvature required; rolling is to roll the TA1 titanium cylinder 2 - 3 circles under the correction curvature; unloading is to gradually remove the load, and then roll the TA1 titanium cylinder multiple times to achieve a straightness of the cylinder surface ≤ 0.05 mm and a roundness ≤ 0.05 mm.

17. The manufacturing method of a high-uniformity and high-grain-size welded titanium cylinder for a cathode roll according to claim 1, characterized in that: In Step 16, ultrasonic impact is used to remove the residual stress on the surface of the TA1 titanium cylinder. The specific process is as follows: The impact power is 780 - 860 W, the impact frequency is 35 - 45 HZ, the amplitude is 35 - 40 μm, and the impact speed is 0.05 - 0.10 m / min.

18. The manufacturing method of a high-uniformity and high-grain-size welded titanium cylinder for a cathode roll as described in claim 1, characterized in that: In Step 17, finish machining is performed on the surface of the TA1 titanium cylinder, including two steps: grinding and polishing. Among them, grinding is to grind the surface of the TA1 titanium cylinder respectively using 40-mesh, 60-mesh, 80-mesh, and 200-mesh grinding wheels. Polishing is to perform mirror processing on the surface using a mirror processing device. Finally, the surface roughness Ra of the cylinder surface ≤ 0.8 μm.

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