A production method of refining the structure of a welded titanium plate for a cathode roller

Abstract

The present application belongs to the technical field of rare metal material modification, and particularly relates to a production method for refining coarse grains of a titanium material welding seam, selects TA1 titanium plate as a research object, processes an X-shaped groove on the titanium plate, adopts manual tungsten argon arc welding to perform multi-pass welding on the TA1 titanium plate, adopts multi-pass cold pressing to perform deformation treatment on the titanium plate after butt welding, and finally performs annealing heat treatment, so as to obtain a welding seam structure similar to a base material structure. The method is beneficial to refining grains in a welding seam area and a heat affected zone, and reducing differences between grains in each area of the welding seam and base material grains.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of rare metal material modification, and particularly relates to a production method of refining the structure of a welded titanium plate for a cathode roller. BACKGROUND

[0002] Electrolytic copper foil is one of the important materials in lithium ion batteries (LIB), printed circuit boards (PCB) and chip packaging substrates (CPS). At present, according to the different production methods of copper foil, it can be generally divided into two categories: calendered copper foil and electrolytic copper foil. The calendered copper foil is an ingot made of pure copper smelting and casting. Then, a series of processes such as hot rolling, cold rolling and annealing are used to prepare the base material. Then, a high-precision rolling mill is used to repeatedly roll the prepared base material to obtain the required thickness and quality of the copper foil. The electrolytic copper foil is manufactured by electrochemical deposition of copper ions in an electrolyte solution. Compared with the disadvantages of complex production process, complex equipment requirements, low production efficiency and high cost of calendered copper foil, electrolytic copper foil has the following advantages: simple production process, minimum equipment cost, easy control of foil thickness precision, high production efficiency and reduced total cost.

[0003] With the rapid development of downstream technologies, the demand for upstream electrolytic copper foil is increasing year by year, especially the quality and quality requirements of copper foil are also getting higher and higher. The key equipment for producing copper foil, cathode roller, copper foil is deposited on the surface of the cathode roller, which is the continuation of the crystal structure of the cathode roller surface. The grade and quality of the copper foil depend on the performance of the cathode roller surface material. The size of the cathode titanium roller surface grain, the smoothness of the outer surface of the cathode titanium roller and the surface roughness are crucial to the production of high-quality copper foil. Today, there are two main methods of manufacturing cathode rollers: spinning (seamless) and welding (seam). The spinning seamless cathode roller technology has a long manufacturing cycle and process, and the price is expensive. The spinning equipment and die for manufacturing large-diameter cylinder sleeves are also very expensive. Compared with the spinning method, the welding method for preparing the cathode roller titanium cylinder sleeve has the advantages of lower cost, high production efficiency, and the manufacturing of titanium cylinder sleeve is not affected by the diameter. Therefore, in the manufacturing of large-diameter titanium cathode rollers, welding manufacturing method must be used. However, due to the existence of a longitudinal weld seam on the surface of the cathode roller titanium cylinder sleeve during the welding production process, there is also a bright band at the corresponding position of the copper foil material, which seriously affects and restricts the high-quality and high-efficiency production of the copper foil.

[0004] The prior art exists some studies on the treatment of the weld to reduce the difference between the weld structure and the base material structure, thereby eliminating the periodic bright band of the weld structure printed on the foil. Among them, CN200410026157 titanium cathode roller body manufacturing method, the weld and the heat affected zone are heated, and the non-deformed base material part is protected by cooling, the weld is upset and then forged flat; then the weld and the heat affected zone are heated again, and the non-deformed base material part is protected by cooling, the weld is upset again and then forged flat, and the process is repeated multiple times, so that the weld is deformed multiple times, and the deformation amount of each time should be more than 30%; heat treatment is performed on the deformed part. The present application deforms the casting structure to change the casting structure into an equiaxed structure which is basically the same as the base material structure, and the process flow is long, resulting in excessive energy consumption. CN202210103233 Preparation method of pure titanium wide-width fine-grain plate for cathode roller, the method emphasizes that the pure titanium plate blank is subjected to first fire rolling, plate shape and surface treatment, cutting, second fire rolling, straightening, annealing, and plate shape and surface treatment to obtain the finished product of wide-width pure titanium fine-grain plate for cathode roller. The process is relatively complicated, and there is no comparison of the microstructure of different areas of the weld. In "Influence of cold rolling process on the microstructure and properties of industrial pure titanium plate weld", the plate is deformed by twice cold rolling process, so that the grain size of the weld processing area is reduced. Although cold pressing + annealing process has some research on refining the grain structure, but the specific problems faced are different for different products. For the titanium plate for cathode roller with a thickness of 8mm, if one or two rolling is used to achieve large deformation, the deformation amount of each time is large. For the thicker plate for cathode roller, it is easy to cause the weld to crack. "Research on weld homogenization treatment process of titanium welded cathode roller for electrolytic copper foil" applies a processing deformation of 60% to 70% to the weld of the pure titanium welded cathode roller, and then performs heat treatment at T3 temperature. The weld structure reaches level 6. It can be seen that the refined structure is still coarse, and the higher the grain refinement level, the more conducive to the production of high-quality copper foil. At present, it is difficult to significantly refine the grain size of the weld area to level 9 to 10. CN200910213091.6 Large titanium cathode roller preparation method solves the problem of large deformation resistance and easy defects by adopting the traditional method of heat treatment after each pass to relieve stress, resulting in a complex process, high energy consumption, and cathode roller pressing to refine the grain size to level 8.

[0005] Therefore, how to control the rolling pass and the single deformation amount, adopt multiple pass cold pressing, and realize large deformation of the weld under the premise of ensuring that the titanium plate weld does not crack, to achieve the significant effect of refining the grain size, is the technical problem to be solved by the present application. SUMMARY

[0006] In order to solve the technical problems, the present application provides a production method of welding titanium plate structure for refining cathode roller.

[0007] The technical scheme adopted by the present application to solve the technical problems is as follows: a production method of welding titanium plate structure for refining cathode roller, comprising the following steps:

[0008] (1) Select TA1 titanium plate as the research object.

[0009] (2) Process X-type groove on the titanium plate.

[0010] (3) Titanium plate pretreatment before welding

[0011] The welding wire is selected to be of the same material as the base material, and the specific composition is shown in Table 1. The joint form adopts X-type groove, the gap of the groove is 1mm, and the angle is 70°. Pretreatment before welding, the test plate is polished by a grinding machine, cleaned with acetone, and the oil stains, dust, and oxide film within 20mm range on both sides of the weld are removed; the workpiece is preheated, the test piece is preheated in a drying oven, and cooled to 50℃; positioning welding is performed after the alcohol is completely volatilized, the weld gap is reserved at both ends of the workpiece, the upper part is reserved for 3mm, the lower part is reserved for 2mm, and the reverse deformation is 1.5°.

[0012] Table 1 Chemical composition of welding wire wt.%

[0013] Element C H N O Fe Ti Content 0.01 0.0016 0.0015 0.029 0.03 Balance

[0014] (4) Welding, cold pressing and annealing heat treatment are adopted for the titanium plate;

[0015] The pretreated X-type groove titanium plate is welded, and the specific welding parameters are as follows: welding current 115A, welding voltage 8-9V, welding speed 5.3cm / min, 5-9 passes of welding, protective gas is pure argon with a purity of 99.99%, and the weld seam height is 7.5-13mm.

[0016] Further, the welding plate is rolled 8-11 times by a two-roller mill, the deformation amount of the welding bead is 59-65%, the deformation amount of the first 4 passes accounts for 70% of the total deformation amount, and the deformation amount of the first pass is close to 20%; the deformation amount of the last 4-7 passes accounts for 30% of the total deformation amount, and the height of the welding plate after the rolling process is 2.15-4.55mm.

[0017] As preferred: the deformation amount of the first four passes accounts for 70% of the total deformation amount, the deformation amount of the first pass is close to 20%, and the deformation amount of each pass is gradually reduced (for example, reduced by 1%-10% on the basis of the previous pass) thereafter; the deformation amount of the last four to seven passes accounts for 30% of the total deformation amount, and the deformation amount of each pass is further gradually reduced on the basis of the fourth pass, and the height of the welded plate after the completion of the rolling process is 2.15-4.55 mm.

[0018] The heat-affected zone grain is obviously refined, and the X-shaped groove few-pass welding plate is more conducive to the refinement of the microstructure of the heat-affected zone.

[0019] With the increase of the deformation amount and the increase of the deformation resistance, the present application controls the rolling pass and the deformation amount of each pass to make the total deformation of the weld be large under the premise that the weld is not cracked, and finally the effect of refining the grains is achieved.

[0020] The present application adopts few-pass welding + multi-pass cold rolling + annealing, including that the welding process adopts X-shaped groove few-pass welding, different heights of welds are obtained under different welding passes, and the method is more conducive to achieving the refinement of the grains in each region of the weld than the commonly used V-shaped groove welding. On this basis, the rolling pass and the single deformation amount are synergistically controlled to obtain finer grains. The welding and cold pressing process of the present application combines the welding and cold pressing processes under different welding processes and different cold pressing deformation processes. The characteristics are that the two production processes jointly affect the microstructure of each region of the weld, the microstructure of each region of the weld is refined, the method process is simple, energy consumption and equipment investment are saved.

[0021] Compared with the traditional hot rolling which needs to be rolled above the recrystallization temperature, the risk of grain growth caused by the heating process can be effectively avoided, and the microstructure is simultaneously refined. The present application reduces energy consumption, better refines the grains, improves the microstructure, and reduces the difference between the weld structure and the base material structure.

[0022] The annealing condition is: 600 DEG C annealing for 1 h. Below this temperature or time, recrystallization is not conducive; above this temperature or time, it is easy to cause grain growth, and the mechanical properties of the titanium plate are poor.

[0023] (5) Sampling, testing and analyzing the titanium plate after welding and cold pressing annealing treatment. The test analysis specifically includes:

[0024] The cross-sectional microstructure is observed by using a DMI-3000M optical microscope.

[0025] The inventive idea of the present application is:

[0026] The present application can make the microstructure of each region of the weld closer to the microstructure of the base material, so X-type groove few-pass welding is performed on the titanium plate, cold pressure annealing heat treatment is performed, and compared with the conventional weld region deformation treatment, the method can better refine the grains in the welding process adjustment.

[0027] The present application has the following advantages:

[0028] (1) The present application adopts an optimized manual tungsten argon arc welding process, and the problem of grain over-coarsening at the welding temperature is avoided under the condition of X-type groove welding with fewer passes.

[0029] (2) The present application adopts cold pressure deformation and annealing heat treatment after welding, and the grains can be more effectively refined after the annealing treatment of the large deformation amount of multiple passes of cold pressure, the performance of the weld is improved, and the performance of the weld is basically consistent with that of the base material. The effect of refining the grains is better than that of the conventional heat treatment, and the problem of grain growth during heating is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is the microstructure of the weld obtained in Example 1;

[0031] Figure 2 is the microstructure of the weld obtained in Example 2;

[0032] Figure 3 is the microstructure of the weld obtained in Example 3;

[0033] Figure 4 is the microstructure of the weld obtained in Example 4;

[0034] Figure 5 is the microstructure of the weld obtained in Example 5;

[0035] Figure 6 is the microstructure of the weld obtained in Example 6;

[0036] Figure 7 is the microstructure of the weld obtained in Example 7;

[0037] Figure 8 is the microstructure of the weld obtained in Example 8;

[0038] Figure 9 is the microstructure of the weld obtained in Example 9;

[0039] Figure 10 is the microstructure of the weld obtained in Example 10;

[0040] Figure 11is the microstructure of the weld obtained in Example 11;

[0041] Figure 12 is the microstructure of the weld obtained in Comparative Example 1. DETAILED DESCRIPTION

[0042] The application is further described below in conjunction with the accompanying drawings. The application is further described below in conjunction with the accompanying drawings, but is not limited thereto.

[0043] In the examples, the welding wire is selected to have the same material as the base material, and has a diameter of Φ3 mm. The specific composition is as follows:

[0044] Table 1 Chemical composition of the welding wire (wt. %)

[0045] Element C H N O Fe Ti Content 0.01 0.0016 0.0015 0.029 0.03 Balance

[0046] The joint form adopts an X-type groove with a gap of 1 mm and an angle of 70°, and multi-layer welding is performed for butt joint. Before welding, the test plate is polished by a grinder, and cleaned with alcohol or acetone, and the oil stains, dust, and oxide film within a range of 20 mm on both sides of the weld are removed; the workpiece is preheated, and the test piece is preheated in a drying oven and cooled to 50°C; positioning welding is performed after the alcohol is completely volatilized, and the weld gap is reserved for positioning welding at both ends of the workpiece, with a reserved gap of 3 mm at the upper part and a reserved gap of 2 mm at the lower part, and a reverse deformation of 1.5°.

[0047] Example 1

[0048] (1) TA1 titanium plate is selected as the research object, and the titanium plate has a specification of 80 mm×30 mm×8 mm;

[0049] (2) The two titanium plates are processed into X-type grooves, and manual tungsten argon arc welding is performed, with specific welding parameters being as follows: welding current 115 A, welding speed 5.3 cm / min, 6 passes of welding, and protective gas 99.99% argon, and the weld has a stack height of 8.6 mm;

[0050] (3) The titanium plates after welding are subjected to cold pressing + annealing heat treatment, the weld surface is polished before the test, the surface oxide layer is removed, and the oil stains are removed by acetone wiping, so that there is no slag existing on the weld surface, the welded test plate is placed under a two-roller mill, the roller speed is 1.6 rpm, the weld placement direction is parallel to the advancing direction of the roller, 11 passes of rolling are performed (the deformation amount of the first 4 passes accounts for about 70% of the total deformation amount, the deformation amount of the first pass is close to 20%, and the deformation amount of each pass is gradually reduced thereafter; the deformation amount of the last 7 passes accounts for 30% of the total deformation amount, and the deformation amount of each pass is gradually reduced on the basis of the fourth pass), until the overall height of the welded plate is 3 mm, the deformation amount of the weld stack height is 65%, and the cold-pressed plate is subjected to annealing heat treatment at 600°C for 1 hour.

[0051] (4) Sampling from the titanium plate after heat treatment, observing the cross-section microstructure by DMI-3000M optical microscope.

[0052] Example 2

[0053] (1) Select TA1 titanium plate as the research object, the titanium plate specification is 80mm x 30mm x 8mm;

[0054] (2) Process X-type groove for the two titanium plates, and perform manual tungsten argon arc welding, the specific welding parameters are: welding current 115A, welding speed 5.3cm / min, layer number 6, protective gas 99.99% argon, and weld seam stack height 8.6mm;

[0055] (3) Perform cold pressing annealing heat treatment on the welded titanium plate, grind the weld seam surface before the test, remove the surface oxidation layer, and then wipe the weld seam surface with acetone to remove oil stains, so that there is no slag between the weld seam surface, place the welded test plate under a two-roller mill, the roller speed is 1.6rpm, the weld seam placement direction is parallel to the roller advancing direction, 10 passes of rolling (the deformation amount of the first 4 passes accounts for about 70% of the total deformation amount, the deformation amount of the first pass is close to 20%, and the deformation amount of each pass is gradually reduced; the deformation amount of the last 6 passes accounts for 30% of the total deformation amount, and the deformation amount of each pass is further gradually reduced based on the fourth pass), until the overall height of the weld plate is 3.5mm, the weld seam stack height deformation amount is 59.3%, and the cold pressing is annealed at 600℃ for 1 hour;

[0056] (4) Sampling from the titanium plate after heat treatment, observing the cross-section microstructure by DMI-3000M optical microscope.

[0057] Example 3

[0058] (1) Select TA1 titanium plate as the research object, the titanium plate specification is 80mm x 30mm x 8mm;

[0059] (2) Process X-type groove for the two titanium plates, and perform manual tungsten argon arc welding, the specific welding parameters are: welding current 115A, welding speed 5.3cm / min, layer number 7, protective gas 99.99% argon, and weld seam stack height 10.1mm;

[0060] (3) The titanium plate after welding is subjected to cold pressing annealing heat treatment. Before the test, the surface of the weld is ground to remove the surface oxide layer, and then is wiped with acetone to remove oil stains, so as to ensure that there is no slag existing on the surface of the weld. The welded test plate is placed under a two-roller mill, the roller speed is 1.6 rpm, the placement direction of the weld is parallel to the advancing direction of the roller, and the plate is rolled for 10 passes (the deformation amount of the first 4 passes accounts for about 70% of the total deformation amount, the deformation amount of the first pass is close to 20%, and the deformation amount of each pass is gradually reduced thereafter; the deformation amount of the last 6 passes accounts for 30% of the total deformation amount, and the deformation amount of each pass is further gradually reduced on the basis of the fourth pass). The overall height of the welded plate is reduced to 3.5 mm (the weld stack height deformation amount is 65%), and the cold-pressed plate is subjected to annealing heat treatment at 600°C for 1 hour.

[0061] (4) The titanium plate after heat treatment is sampled, and the cross-sectional microstructure is observed by using a DMI-3000M optical microscope.

[0062] Example 4

[0063] (1) TA1 titanium plate is selected as the research object, and the titanium plate has a specification of 80 mm x 30 mm x 8 mm.

[0064] (2) The two titanium plates are processed to have X-shaped grooves, and are welded by using a manual tungsten argon arc welding method. The specific welding parameters are as follows: welding current 115 A, welding speed 5.3 cm / min, number of layers 7, protective gas 99.99% argon, and weld stack height 10.1 mm.

[0065] (3) The titanium plate after welding is subjected to cold pressing annealing heat treatment. Before the test, the surface of the weld is ground to remove the surface oxide layer, and then is wiped with acetone to remove oil stains, so as to ensure that there is no slag existing on the surface of the weld. The welded test plate is placed under a two-roller mill, the roller speed is 1.6 rpm, the placement direction of the weld is parallel to the advancing direction of the roller, and the plate is rolled for 10 passes (the deformation amount of the first 4 passes accounts for about 70% of the total deformation amount, the deformation amount of the first pass is close to 20%, and the deformation amount of each pass is gradually reduced thereafter; the deformation amount of the last 6 passes accounts for 30% of the total deformation amount, and the deformation amount of each pass is further gradually reduced on the basis of the fourth pass). The overall height of the welded plate is reduced to 3.5 mm (the weld stack height deformation amount is 65%), and the cold-pressed plate is subjected to annealing heat treatment at 600°C for 1 hour.

[0066] (4) The titanium plate after heat treatment is sampled, and the cross-sectional microstructure is observed by using a DMI-3000M optical microscope.

[0067] Example 5

[0068] (1) TA1 titanium plate is selected as the research object, and the titanium plate has a specification of 80 mm x 30 mm x 8 mm.

[0069] (2) The two titanium plates were machined with X-shaped grooves and then manually tungsten inert gas welding was performed. The specific welding parameters were: welding current 115A, welding speed 5.3cm / min, 8 welding passes, shielding gas 99.99% argon, and weld height 11.5mm.

[0070] (3) The welded titanium plate was subjected to cold pressing annealing heat treatment. Before the test, the weld surface was ground to remove the surface oxide layer, and then wiped with acetone to remove oil stains to ensure that there were no slag inclusions on the weld surface. The welded test plate was placed under a two-roll mill with a roll speed of 1.6 rpm. The weld placement direction was parallel to the roll forward direction. The plate was rolled in 9 passes to the overall height of the weld plate (the deformation amount of the first 4 passes accounted for about 70% of the total deformation amount, the deformation amount of the first pass was close to 20%, and the deformation amount of each subsequent pass gradually decreased; the deformation amount of the last 5 passes accounted for 30% of the total deformation amount, and the deformation amount of each pass was further gradually reduced based on the fourth pass), to 4 mm (the deformation amount of weld height was 65%). After cold pressing, the plate was annealed at 600℃ for 1 hour.

[0071] (4) Samples were taken from the heat-treated titanium plate and the cross-sectional microstructure was observed using a DMI-3000M optical microscope.

[0072] Example 6

[0073] (1) TA1 titanium plate was selected as the research object. The titanium plate has a size of 80mm×30mm×8mm.

[0074] (2) The two titanium plates were machined with X-shaped grooves and then manually tungsten inert gas welding was performed. The specific welding parameters were: welding current 115A, welding voltage 8-9V, welding speed 5.3cm / min, 8 welding passes, shielding gas 99.99% argon, and weld height 11.5mm.

[0075] (3) The welded titanium plate was subjected to cold pressing annealing heat treatment. Before the test, the weld surface was ground to remove the surface oxide layer, and then wiped with acetone to remove oil stains to ensure that there were no slag inclusions on the weld surface. The welded test plate was placed under a two-roll mill with a roll speed of 1.6 rpm. The weld placement direction was parallel to the roll forward direction. The plate was rolled in 8 passes to the overall height of the welded plate (the deformation amount of the first 4 passes accounted for about 70% of the total deformation amount, the deformation amount of the first pass was close to 20%, and the deformation amount of each subsequent pass gradually decreased; the deformation amount of the last 4 passes accounted for 30% of the total deformation amount, and the deformation amount of each pass was further gradually reduced based on the fourth pass), to 4.5 mm (the deformation amount of weld height was 61%). After cold pressing, the plate was annealed at 600℃ for one hour.

[0076] (4) Samples were taken from the heat-treated titanium plate and the cross-sectional microstructure was observed using a DMI-3000M optical microscope.

[0077] Example 7

[0078] (1) TA1 titanium plate was selected as the research object. The titanium plate has a size of 80mm×30mm×8mm.

[0079] (2) The two titanium plates were machined with X-shaped grooves and then manually tungsten inert gas welding was performed. The specific welding parameters were: welding current 115A, welding voltage 8-9V, welding speed 5.3cm / min, 9 welding passes, shielding gas 99.99% argon, and weld height 13mm.

[0080] (3) The welded titanium plate was subjected to cold pressing annealing heat treatment. Before the test, the weld surface was ground to remove the surface oxide layer, and then wiped with acetone to remove oil stains to ensure that there were no slag inclusions on the weld surface. The welded test plate was placed under a two-roll mill with a roll speed of 1.6 rpm. The weld placement direction was parallel to the roll forward direction. The plate was rolled in 8 passes to the overall height of the weld plate (the deformation amount of the first 4 passes accounted for about 70% of the total deformation amount, the deformation amount of the first pass was close to 20%, and the deformation amount of each subsequent pass gradually decreased; the deformation amount of the last 4 passes accounted for 30% of the total deformation amount, and the deformation amount of each pass was further gradually reduced based on the fourth pass), to 4.5 mm (the deformation amount of weld height was 65%). After cold pressing, the plate was annealed at 600℃ for 1 hour.

[0081] (4) Samples were taken from the heat-treated titanium plate and the cross-sectional microstructure was observed using a DMI-3000M optical microscope.

[0082] Example 8:

[0083] The difference between Example 8 and Example 1 is that the annealing temperature is different.

[0084] (1) TA1 titanium plate was selected as the research object. The titanium plate has a size of 80mm×30mm×8mm.

[0085] (2) The two titanium plates were machined with X-shaped grooves and then manually tungsten inert gas welding was performed. The specific welding parameters were: welding current 115A, welding voltage 8-9V, welding speed 5.3cm / min, welding 6 passes, shielding gas 99.99% argon, and weld height 8.6mm.

[0086] (3) The welded titanium plate was subjected to cold pressing annealing heat treatment. Before the test, the surface of the weld was ground to remove the surface oxide layer, and then wiped with acetone to remove oil stains to ensure that there was no slag inclusion on the surface of the weld. The welded test plate was placed under a two-roll mill with a roll speed of 1.6 rpm. The weld was placed in the direction of the roll advance parallel to the direction of the roll advance. The plate was rolled in 11 passes (the deformation of the first 4 passes accounted for about 70% of the total deformation, the deformation of the first pass was close to 20%, and the deformation of each subsequent pass gradually decreased; the deformation of the last 7 passes accounted for 30% of the total deformation, and the deformation of each pass was further gradually reduced based on the fourth pass). The plate was rolled until the overall height of the welded plate was 3 mm (the deformation of the weld height was 65%). After cold pressing, the plate was annealed at 650℃ for 1 hour.

[0087] (4) Samples were taken from the heat-treated titanium plate and the cross-sectional microstructure was observed using a DMI-3000M optical microscope.

[0088] Example 9

[0089] (1) TA1 titanium plate was selected as the research object. The titanium plate has a size of 80mm×30mm×8mm.

[0090] (2) The two titanium plates were machined with X-shaped grooves and then manually tungsten inert gas welding was performed. The specific welding parameters were: welding current 115A, welding speed 5.3cm / min, number of layers 6, shielding gas 99.99% argon, and weld height 8.6mm.

[0091] (3) The welded titanium plate was subjected to cold pressing annealing heat treatment. Before the test, the surface of the weld was ground to remove the surface oxide layer, and then wiped with acetone to remove oil stains to ensure that there was no slag inclusion on the surface of the weld. The welded test plate was placed under a two-roll mill with a roll speed of 1.6 rpm. The weld was placed in the direction of the roll forward and parallel to the direction of the roll forward. The plate was rolled in 11 passes (the deformation of the first 4 passes accounted for about 70% of the total deformation, the deformation of the first pass was close to 20%, and the deformation of each subsequent pass gradually decreased; the deformation of the last 7 passes accounted for 30% of the total deformation, and the deformation of each pass was further gradually reduced based on the fourth pass). The overall height of the welded plate was rolled to 2.15 mm, and the deformation of the weld was 75%. After cold pressing, the plate was annealed at 600℃ for 1 hour.

[0092] (4) Samples were taken from the heat-treated titanium plate and the cross-sectional microstructure was observed using a DMI-3000M optical microscope.

[0093] When the deformation amount in Example 1 is 65%, the microstructure of each area of ​​the weld is significantly refined, and the microstructure of the weld area and the heat-affected zone can no longer be distinguished, thus achieving the invention objective. However, Example 9 further increases the deformation amount, which increases the cost, and the thickness of the cathode roller is too thin, which affects the performance of the product and makes it prone to cracking.

[0094] Example 10

[0095] (1) TA1 titanium plate was selected as the research object. The titanium plate has a size of 80mm×30mm×8mm.

[0096] (2) The two titanium plates were machined with X-shaped grooves and then manually tungsten inert gas welding was performed. The specific welding parameters were: welding current 115A, welding speed 5.3cm / min, number of layers 6, shielding gas 99.99% argon, and weld height 8.6mm.

[0097] (3) The welded titanium plate was subjected to cold pressing annealing heat treatment. Before the test, the surface of the weld was ground to remove the surface oxide layer, and then wiped with acetone to remove oil stains to ensure that there was no slag inclusion on the surface of the weld. The welded test plate was placed under a two-roll mill with a roll speed of 1.6 rpm. The weld placement direction was parallel to the roll forward direction. The plate was rolled in 13 passes until the overall height of the welded plate was 3 mm. The weld height deformation was 65%. After cold pressing, the plate was annealed at 600℃ for 1 hour.

[0098] (4) Samples were taken from the heat-treated titanium plate and the cross-sectional microstructure was observed using a DMI-3000M optical microscope.

[0099] Example 1 shows that the goal of refining each area of ​​the weld has been achieved, and there is no need to add more rolling passes, which would increase production costs.

[0100] Example 11

[0101] The difference between Example 11 and Example 1 is that the weld bead buildup is lower, while the other operations are the same.

[0102] (1) TA1 titanium plate was selected as the research object. The titanium plate has a size of 80mm×30mm×8mm.

[0103] (2) X-shaped grooves were machined on the two titanium plates and manual tungsten inert gas welding was performed. The specific welding parameters were: welding current 115A, welding speed 5.3cm / min, number of layers 5, shielding gas 99.99% argon, and weld height 7.5mm.

[0104] (3) The welded titanium plate was subjected to cold pressing annealing heat treatment. Before the test, the surface of the weld was ground to remove the surface oxide layer, and then wiped with acetone to remove oil stains to ensure that there were no slag inclusions on the surface of the weld. The welded test plate was placed under a two-roll mill with a roll speed of 1.6 rpm. The weld placement direction was parallel to the roll forward direction. The plate was rolled in 11 passes until the overall height of the welded plate was 2.6 mm. The weld height deformation was 65%. After cold pressing, the plate was annealed at 600℃ for 1 hour.

[0105] (4) Samples were taken from the heat-treated titanium plate and the cross-sectional microstructure was observed using a DMI-3000M optical microscope.

[0106] Example 11 has fewer welding passes and a lower weld bead height, which is not conducive to post-cold pressing, makes it prone to defects, and is not conducive to grain refinement.

[0107] Comparative Example 1

[0108] (1) TA1 titanium plate was selected as the research object. The titanium plate has a size of 80mm×30mm×8mm.

[0109] (2) For the X-shaped groove, manual tungsten inert gas welding is used. The specific welding parameters are: welding current 115A, welding voltage 8-9V, welding speed 5.3cm / min, 6 welding passes, shielding gas is 99.99% argon, and weld height is 8.6mm.

[0110] (3) The welded titanium plate was subjected to cold pressing annealing heat treatment. Before the test, the weld surface was ground to remove the surface oxide layer, and then wiped with acetone to remove oil stains to ensure that there was no slag inclusion on the weld surface. The welded test plate was cold pressed to a height of 3mm (the weld height deformation was 65%), and then annealed at 600℃ for 1 hour after cold pressing.

[0111] (4) Samples were taken from the heat-treated titanium plate and the cross-sectional microstructure was observed using a DMI-3000M optical microscope.

[0112] Table 3 Grain grades of welds and heat-affected zones under different processes.

[0113]

[0114]

[0115] Comparing the grain size grades of the weld zone and heat-affected zone of the welded plates under different process conditions, it can be seen that compared with the welded plates obtained by conventional production processes, after adjustment of the welding process and cold pressing process, and after annealing heat treatment, the grain size grades of the weld zone in Example 1 are 9-10, and the grain size grades of the heat-affected zone are 8.5-10; the grain size grades of the weld zone in Example 2 are 8.5-9, and the grain size grades of the heat-affected zone are 8-9; the grain size grades of the weld zone in Example 3 are 8-9, and the grain size grades of the heat-affected zone are 7.5-9; the grain size grades of the weld zone in Example 4 are 7.5-9, and the grain size grades of the heat-affected zone are 7-9; the grain size grades of the weld zone in Example 5 are 7.5-9, and the grain size grades of the heat-affected zone are 7-9; the grain size grades of the weld zone in Example 6 are 7-9, and the grain size grades of the heat-affected zone are 6.5-9; and the grain size grades of the weld zone in Example 7 are 7-10, and the grain size grades of the heat-affected zone are 8.5-10. The grain size grades are 6.5 to 10. In Example 8, the weld zone grain size grade is 8.5 to 9, and the heat-affected zone grain size grade is 8 to 9. In Example 9, the weld zone grain size grade is 9 to 10, and the heat-affected zone grain size grade is 8.5 to 10. In Example 10, the weld zone grain size grade is 9 to 10, and the heat-affected zone grain size grade is 8.5 to 10. In Example 11, the weld zone grain size grade is 8.5 to 9, and the heat-affected zone grain size grade is 8 to 10. The grain size of the weld zone in Comparative Example 1 was 6.5–9, and the grain size of the heat-affected zone was also 6–9. The overall grain size difference of the weld plate gradually decreased, and the grain size difference in each region also gradually decreased. The grain size of the weld zone in Comparative Example 1 increased from 6.5–9 to 9–10, and the grain size of the heat-affected zone in Comparative Example 1 increased from 6–9 to 8.5–10, with the grain size difference in each region also decreasing. This means that welding and cold-pressing annealing heat treatment can better refine the grains, improve the microstructure, and reduce the difference between the weld structure and the base metal structure (9–10).

[0116] from Figures 1-8 As can be seen from the figure, the coarse columnar grains of the weld become refined after welding, cold pressing, and annealing heat treatment. With the X-groove and fewer welding passes, and with increasing deformation under multi-pass rolling, the acicular secondary α-phase structure in the weld zone and heat-affected zone after annealing becomes morphologically more similar to the base metal, further reducing the difference between the weld and base metal structures. Specifically, in manual tungsten inert gas welding (TIG) with 6 passes, the grain size in the weld zone and heat-affected zone after annealing is most similar to the base metal when annealing with a deformation of 65% under 11 passes and 65% rolling.

[0117] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A method for producing a refined microstructure of welded titanium plate for cathode rollers, characterized in that: The process steps of the method are as follows: (1) Select TA1 titanium plate and use a milling machine to process an X-shaped bevel on the titanium plate; (2) The welding wire is made of the same material as the titanium plate base material. The titanium plate is welded in 5 to 9 passes using manual tungsten inert gas welding. The weld height after welding is 7.5 to 13 mm. (3) The welded titanium plate is subjected to multiple cold pressing and annealing heat treatment: the welded titanium plate is subjected to 8-11 cold pressing deformations until the deformation of the weld bead is 59-65%, and then subjected to heat treatment at 600-650℃; the deformation of the first 4 passes accounts for 70% of the total deformation, the deformation of the first pass is close to 20%; the deformation of the last 4-7 passes accounts for 30% of the total deformation, and the height of the welded plate after the rolling process is 2.15-4.55mm.

2. The method for producing refined welded titanium plate microstructure for cathode rollers according to claim 1, characterized in that: In step (1), the dimensions of the X-shaped bevel of the titanium plate are 1mm gap and 70º angle.

3. The method for producing refined welded titanium plate microstructure for cathode rollers according to claim 1, characterized in that: Pre-welding pretreatment involves grinding the test plate with a grinding wheel, cleaning with acetone to remove oil, dust, and oxide film from both sides of the weld bead within a 20mm range; preheating the workpiece by preheating it in a drying oven and cooling it to 50℃; tack welding by tack welding after the alcohol has completely evaporated, leaving a weld gap at both ends of the workpiece, with a 3mm gap at the top and a 2mm gap at the bottom, and a reverse deformation of 1.5°.

4. The method for producing refined welded titanium plate microstructure for cathode rollers according to claim 1, characterized in that: The welding steps in step (2) are as follows: welding current of 115A, welding voltage of 8~9V, welding speed of 5.3cm / min, and shielding gas of 99.99% argon.

5. The method for producing refined welded titanium plate microstructure for cathode rollers according to claim 1, characterized in that: The rolls are rotated at 1.6 rpm and subjected to annealing heat treatment at 600℃ for 1 hour.

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