A method for preparing CuMn flat belt for horizontal splicing belt

Abstract

The invention relates to the technical field of CuMn flat strip preparation, and in particular to a method for preparing a CuMn flat strip for a transverse splicing strip, comprising: S1, batching, S2, vacuum melting and casting, S3, forging, S4, hot rolling treatment, and S5, post-treatment. The CuMn flat strip prepared by the invention through vacuum melting and then casting, and then forging, hot rolling treatment, and post-treatment has good product quality, and the internal inclusions and defects of the material are significantly less than those of the finished products prepared by other methods, the material performance is stable and consistent, the welding quality of the transverse splicing strip is reliable, and the requirements of the CuMn flat strip on the current market are fully met. The overall process of the invention is simple to operate, has the characteristics of industrialized production, and is suitable for large-scale promotion.

Description

Technical Field

[0001] The invention relates to the technical field of CuMn flat strip preparation, and in particular to a method for preparing a CuMn flat strip for a transverse splicing belt. Background Art

[0002] CuMn alloy is a kind of resistance material with very small resistance temperature coefficient, low electrothermal potential to copper, high resistance stability, and is a superior resistance alloy material. It is mainly used to make standard resistors, shunt resistors, precision or ordinary resistance elements, high-level voltage, current, bridge, potentiometer and other precision resistance elements for instruments and meters, and is widely used in mobile phones, power grids, new energy vehicles and other fields.

[0003] CuMn flat strips for horizontal splicing can be stamped as shunts for relay components, and are commonly used in smart meters, automobiles, charging piles, etc. At present, most of the high-end CuMn alloys in the domestic market are imported, and the performance of domestic CuMn flat strips is average, and domestic substitution is imminent.

[0004] At present, there are mainly the following methods for preparing CuMn flat strips for horizontal splicing in China: some CuMn flat strips are obtained by non-vacuum flat drawing to obtain rod materials, and then the rod materials of suitable sizes are obtained by turning the outer circle, drawing, annealing and pickling, and then rolling and fine drawing to obtain finished flat strips. The finished flat strips obtained by this method have many inclusions and low material performance, and are mostly used in mid- and low-end products. Some CuMn flat strips use vacuum melting and casting ingots, and then obtain wide plates and strips through forging and rolling, and finally the finished products are cut to obtain flat strips of suitable sizes. The finished products obtained by this method are not conducive to the subsequent horizontal splicing welding, which affects the use of the back end. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a method for preparing a CuMn flat strip for a transverse splicing strip.

[0006] The technical solution of the present invention is: a method for preparing a CuMn flat strip for a horizontal splicing strip, comprising:

[0007] S1. Ingredients

[0008] Using high-purity electrolytic copper plate, nickel plate, metal chromium, copper-iron master alloy, industrial silicon and electrolytic manganese as raw materials, the raw material mixture is obtained by proportioning according to the following ratios: Mn content is 11% to 13%, Ni content is 2% to 3%, Cr content is 0.01% to 0.02%, Fe content is 0.01% to 0.03%, Si content is 0.1% to 0.3%, and the balance is Cu;

[0009] S2. Vacuum melting

[0010] The raw material mixture is loaded into the prefabricated crucible of the medium frequency furnace by a one-time charging method, the furnace cover is closed, and the vacuum is evacuated to P less than or equal to 10Pa; the temperature is raised to 1250℃~1350℃ by intermittent heating, and after the raw material mixture is melted, high-purity argon is filled into the furnace body; the raw material mixture is refined at 1200℃~1250℃ for 3min to obtain the raw material melt; CaO, Al 2 O 3 , CaF 2 and Na 3 AlF 6 Mix in any ratio to obtain a mixture; add 0.05% of the deoxidizer and 0.05% of the mixture accounting for the weight of the raw material melt to the raw material melt, stir for 1h to 1.5h at a temperature of 1180°C to 1220°C, and the speed of the stirring device is 35r / min to 45r / min, and then add 0.05% of the deoxidizer and 0.05% of the mixture accounting for the weight of the raw material melt to the raw material melt and stir for 0.8h to 1h;

[0011] The casting temperature of the raw material melt is controlled at 1150°C to 1200°C, and the casting is started after the temperature is maintained for 30 seconds; a steel mold is used for casting, and shrinkage is compensated for 3 to 5 times to obtain an ingot;

[0012] S3, Forging

[0013] The riser and bottom plate of the ingot are sawed, and the surface is turned to be bright; then forging is carried out, and the forging temperature is controlled to be 800℃~900℃, and the temperature is kept for 3 hours to forge into a round bar of φ9.5~φ10.5. After cooling, the surface of the round bar is turned to obtain a bar material;

[0014] S4, hot rolling treatment

[0015] The forged bar is hot rolled at a temperature of 800℃~900℃ for 3h~4h, and a thin bar of φ14.5~φ15.5 is obtained by hot rolling, and then coiled; the coiled bar is turned to ensure that the surface of the bar is smooth and free of oxides and other inclusions, and turned to a diameter of φ12.5~φ13.5 to obtain the bar;

[0016] S5. Post-processing

[0017] S5-1, drawing, S5-2, annealing, S5-3, pickling, S5-4, rolling, S5-5, re-annealing, S5-6, fine drawing, S5-7, finished product online annealing, S5-8, testing and packaging.

[0018] Furthermore, the drawing step in step S5-1 is: drawing the rod material to control the deformation amount of each process to be less than or equal to 30%.

[0019] Description: Drawing is to forcibly stretch the steel bar under normal temperature conditions with a tensile stress exceeding the original yield point strength of the steel bar, causing the steel bar to undergo plastic deformation, which can increase the yield point strength of the steel bar and save steel.

[0020] Furthermore, step S5-2 annealing step is: annealing the drawn rod material, using hydrogen as a protective atmosphere, controlling the annealing temperature to 700° C. to 800° C., and keeping the temperature for 3 hours.

[0021] Description: Slowly heating the metal, keeping it for a sufficient time, and then cooling it at an appropriate rate can reduce hardness and improve machinability; reduce residual stress, reduce deformation and crack tendency; refine grains, adjust structure, and eliminate structural defects.

[0022] Further, step S5-3 pickling step is: pickling the annealed rod material to remove the surface oxide scale, the pickling solution is selected from sulfuric acid accounting for 30wt% of the total mass of the pickling solution, 10wt% of nitric acid and the rest of water, after pickling, it is washed with warm water and air-dried to obtain the material; the pickled material is repeatedly drawn, annealed and pickled until the material size reaches Get the material rod.

[0023] Description: 30% sulfuric acid solution can be used to remove the oxide scale and rust on the surface of the rod material; immerse the rod material in the sulfuric acid solution to remove the oxide film on the metal surface.

[0024] Furthermore, the rolling step of step S5-4 is: directly performing a round flattening operation on the material rod, using a multi-pass rolling method, controlling the deformation ratio of each rolling pass to be within 30%, rolling to a thickness of 1.5mm to 3mm, a width of 10mm to 15mm, and coiling to obtain a semi-finished flat strip.

[0025] Description: The material rod can be directly rolled into a semi-finished flat strip of the required size.

[0026] Furthermore, step S5-5 is a re-annealing step: re-annealing the rolled semi-finished flat strip at a temperature of 700°C to 800°C for 3 hours; pickling the annealed semi-finished flat strip to remove the surface oxide scale, and the pickling solution is a mixture of 30wt% sulfuric acid, 10wt% nitric acid and the remainder water accounting for 30wt% of the total mass of the pickling solution.

[0027] Note: Re-annealing the rolled semi-finished flat strip can reduce the hardness and improve the processability; after pickling, the surface is clean and bright, not easy to lose gloss and fade, and the surface does not turn yellow.

[0028] Furthermore, step S5-6 is a finishing drawing step: the pickled semi-finished flat strip is drawn using a mold as required to obtain flat strips of one or more specifications of 1.5mm*15mm or 1.5mm*12mm or 1.5mm*11mm or 1mm*11mm or 1mm*12mm or 1mm*15mm.

[0029] Description: Fine drawing can effectively draw the pickled semi-finished flat strip into a flat strip close to the required specifications.

[0030] Furthermore, step S5-7 is a finished product online annealing step: the finely drawn flat strip is subjected to finished product online annealing at an annealing temperature of 700°C to 800°C and a stepping speed of 5m / min to 10m / min, and is rolled up to obtain a finished flat strip.

[0031] Description: Through online annealing of finished products, the residual stress of the flat strip can be reduced, the size can be stabilized, and the deformation and crack tendency of the flat strip can be reduced; the grains can be refined, the structure can be adjusted, and the structural defects can be eliminated.

[0032] Furthermore, step S5-8 is a testing and packaging step: sampling and testing the resistivity, temperature coefficient of resistance, hardness, and surface roughness of the finished flat belt; observing the appearance to ensure that the surface is smooth and flat, and packaging and shipping the flat belt that has passed the test.

[0033] Note: Testing various coefficients can comprehensively examine the finished flat belt, observe the appearance to ensure the surface is smooth and flat, and can ensure the quality of the finished flat belt.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] (1) The preparation method of the CuMn flat strip of the present invention adopts high-purity electrolytic copper plate, nickel plate, metallic chromium, copper-iron master alloy, industrial silicon and electrolytic manganese as raw materials for proportioning, which can reduce and stabilize the temperature coefficient of resistance and ensure that the resistivity of the material remains relatively constant during different temperature changes.

[0036] (2) The preparation method of the CuMn flat strip of the present invention can remove impurity defects in the raw material melt by secondary addition of the deoxidizer and the mixture, thereby ensuring the purity of the internal structure of the raw material melt and effectively improving the product quality of the finished flat strip.

[0037] (3) The CuMn flat strip prepared by the preparation method of the CuMn flat strip of the present invention has significantly fewer internal inclusions and defects than the finished products prepared by other methods, and the product quality is better; the material performance is stable and consistent, and the welding quality of the cross-joined strip is reliable, which fully meets the requirements of CuMn flat strips on the current market; the overall process of the present invention is simple to operate and has the characteristics of industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a work flow chart of the present invention. DETAILED DESCRIPTION

[0039] Example 1

[0040] A method for preparing a CuMn flat strip for a horizontal splicing strip comprises:

[0041] S1. Ingredients

[0042] Using high-purity electrolytic copper plate, nickel plate, metallic chromium, copper-iron master alloy, industrial silicon and electrolytic manganese as raw materials, the raw material mixture is obtained by proportioning according to the content of Mn of 12%, the content of Ni of 2.5%, the content of Cr of 0.015%, the content of Fe of 0.02%, the content of Si of 0.2% and the balance of Cu;

[0043] S2. Vacuum melting

[0044] The raw material mixture is loaded into the prefabricated crucible of the medium frequency furnace by a one-time charging method, the furnace cover is closed, and the vacuum is evacuated to P less than or equal to 10Pa; the temperature is raised to 1300℃ by intermittent heating, and high-purity argon is filled into the furnace body after the raw material mixture is melted; the raw material melt is refined at 1225℃ for 3min; CaO, Al 2 O 3 , CaF 2 and Na 3 AlF 6 Mixing in equal weight ratios to obtain a mixture; adding 0.05% of the deoxidizer and 0.05% of the mixture accounting for the weight of the raw material melt to the raw material melt, stirring for 1.25 hours at a temperature of 1200° C., with a stirring device speed of 40 r / min, and then adding 0.05% of the deoxidizer and 0.05% of the mixture accounting for the weight of the raw material melt to the raw material melt and stirring for 0.9 hours;

[0045] The casting temperature of the raw material melt is controlled at 1175°C, maintained for 30 seconds, and then the casting begins; a steel mold is used for casting, and shrinkage is compensated 4 times to obtain an ingot;

[0046] S3, Forging

[0047] The riser and bottom plate of the ingot are sawed, and the surface is turned to be bright; then forging is carried out, and the forging temperature is controlled to be 850℃, and the temperature is kept for 3 hours to forge into a φ10 round bar. After cooling, the surface of the round bar is turned to obtain a bar material;

[0048] S4, hot rolling treatment

[0049] The forged bar is hot rolled at 850℃ for 3.5h, and then hot rolled to obtain a φ15 thin bar, which is then coiled. The coiled bar is turned to ensure that the surface of the bar is smooth and free of oxides and other inclusions, and then turned to a diameter of φ13 to obtain the bar.

[0050] S5. Post-processing

[0051] S5-1, drawing, S5-2, annealing, S5-3, pickling, S5-4, rolling, S5-5, re-annealing, S5-6, fine drawing, S5-7, finished product online annealing, S5-8, testing and packaging;

[0052] Step S5-1: the drawing step is: drawing the rod material, controlling the deformation amount of each pass to be less than or equal to 30%;

[0053] Step S5-2: Annealing step: annealing the drawn rod material, using hydrogen as a protective atmosphere, controlling the annealing temperature to 750°C, and keeping the temperature for 3 hours;

[0054] Step S5-3: Pickling step: pickling the annealed rod material to remove the surface oxide scale, the pickling solution is a mixture of 30wt% sulfuric acid, 10wt% nitric acid and the rest water, and after pickling, it is washed with warm water and air-dried to obtain the material; the pickled material is repeatedly drawn, annealed and pickled until the material size reaches Get the material rod;

[0055] Step S5-4: rolling step: directly rolling the material rod into a round flat, using a multi-pass rolling method, controlling the deformation ratio of each rolling pass to be within 30%, rolling to a thickness of 2.25 mm and a width of 12.5 mm, and then rolling to obtain a semi-finished flat strip;

[0056] Step S5-5: re-annealing step: re-annealing the rolled semi-finished flat strip at a temperature of 750°C for 3 hours; pickling the annealed semi-finished flat strip to remove the surface oxide scale, the pickling solution is a mixture of 30wt% sulfuric acid, 10wt% nitric acid and the remainder water;

[0057] Step S5-6: the fine drawing step is: the pickled semi-finished flat strip is drawn using a mold according to the requirements to obtain a flat strip with a specification of 1.5mm*11mm;

[0058] Step S5-7: the finished product online annealing step is: the finished flat strip is subjected to finished product online annealing at an annealing temperature of 750°C and a stepping speed of 7.5 m / min, and is rolled up to obtain a finished flat strip;

[0059] Step S5-8 is the inspection and packaging step: sampling and testing the resistivity, temperature coefficient of resistance, hardness, and surface roughness of the finished flat belt; observing the appearance to ensure that the surface is smooth and flat, and packaging and shipping the flat belt that has passed the inspection.

[0060] Example 2

[0061] The difference between this embodiment and Example 1 is that high-purity electrolytic copper plate, nickel plate, metallic chromium, copper-iron master alloy, industrial silicon and electrolytic manganese are used as raw materials, and the raw material mixture is obtained by proportioning according to the Mn content of 11%, the Ni content of 2%, the Cr content of 0.01%, the Fe content of 0.01%, the Si content of 0.1%, and the balance of Cu.

[0062] Example 3

[0063] The difference between this embodiment and Example 1 is that high-purity electrolytic copper plate, nickel plate, metallic chromium, copper-iron master alloy, industrial silicon and electrolytic manganese are used as raw materials, and the raw material mixture is obtained by proportioning according to the Mn content of 13%, the Ni content of 3%, the Cr content of 0.02%, the Fe content of 0.03%, the Si content of 0.3%, and the balance of Cu.

[0064] Example 4

[0065] The difference between this embodiment and embodiment 1 is that intermittent heating is used to raise the temperature to 1250°C, and after the raw material mixture is melted, high-purity argon is filled into the furnace body; refining is carried out at 1200°C for 3 minutes to obtain a raw material melt; 0.05% of the deoxidizer and 0.05% of the mixture by weight of the raw material melt are added to the raw material melt, and stirred for 1 hour at a temperature of 1180°C, with a stirring device speed of 35r / min, and then 0.05% of the deoxidizer and 0.05% of the mixture by weight of the raw material melt are added to the raw material melt and stirred for 0.8h;

[0066] The casting temperature of the raw material melt was controlled at 1150°C and maintained for 30 seconds before starting casting; a steel mold was used for casting and shrinkage was compensated 3 times to obtain an ingot.

[0067] Example 5

[0068] The difference between this embodiment and embodiment 1 is that intermittent heating is used to raise the temperature to 1350° C., and after the raw material mixture is melted, high-purity argon is filled into the furnace body; refining is carried out at 1250° C. for 3 minutes to obtain a raw material melt; 0.05% of the deoxidizer and 0.05% of the mixture by weight of the raw material melt are added to the raw material melt, and stirred for 1.5 hours at a temperature of 1220° C., and the speed of the stirring device is 45 r / min, and then 0.05% of the deoxidizer and 0.05% of the mixture by weight of the raw material melt are added to the raw material melt and stirred for 1 hour;

[0069] The casting temperature of the raw material melt was controlled at 1200°C and maintained for 30 seconds before starting casting; a steel mold was used for casting and shrinkage was compensated 5 times to obtain an ingot.

[0070] Example 6

[0071] The difference between this embodiment and embodiment 1 is that the riser and bottom plate of the ingot are sawn and the surface is turned to be bright; then forging is carried out, the forging temperature is controlled to 800°C, and the temperature is kept for 3 hours to forge into a φ9.5 round bar.

[0072] Example 7

[0073] The difference between this embodiment and embodiment 1 is that the riser and bottom plate of the ingot are sawn and the surface is turned to be bright; then forging is carried out, the forging temperature is controlled to 900°C, and the temperature is kept for 3 hours to forge into a round bar of φ10.5.

[0074] Example 8

[0075] The difference between this embodiment and embodiment 1 is that the forged bar is hot rolled at a temperature of 800°C for 3 hours. The thin rod material is then rolled up.

[0076] Example 9

[0077] The difference between this embodiment and embodiment 1 is that the forged bar is hot rolled at a heating temperature of 900°C for 4 hours. The thin rod material is then rolled up.

[0078] Example 10

[0079] The difference between this embodiment and embodiment 1 is that the rolled rod material is subjected to outer rounding treatment to ensure that the surface of the rod material is smooth and free of inclusions such as oxides, and the rod material is turned to a diameter of φ12.5 to obtain the rod material.

[0080] Embodiment 11

[0081] The difference between this embodiment and embodiment 1 is that the rolled rod material is subjected to outer rounding treatment to ensure that the surface of the rod material is smooth and free of inclusions such as oxides, and the rod material is turned to a diameter of φ13.5 to obtain the rod material.

[0082] Example 12

[0083] The difference between this embodiment and embodiment 1 is that the rod material after drawing is annealed, hydrogen is used as the protective atmosphere, the annealing temperature is controlled to 700° C., and the temperature is kept for 3 hours.

[0084] Embodiment 13

[0085] The difference between this embodiment and embodiment 1 is that the rod material after drawing is annealed, hydrogen is used as the protective atmosphere, the annealing temperature is controlled to 800° C., and the temperature is kept for 3 hours.

[0086] Embodiment 14

[0087] The difference between this embodiment and embodiment 1 is that the pickled material is repeatedly drawn, annealed and pickled until the material size reaches Get the material rod.

[0088] Embodiment 15

[0089] The difference between this embodiment and embodiment 1 is that the pickled material is repeatedly drawn, annealed and pickled until the material size reaches Get the material rod.

[0090] Example 16

[0091] The difference between this embodiment and embodiment 1 is that the material rod is directly subjected to a round flattening operation to be rolled to a thickness of 1.5 mm and a width of 10 mm, and then rolled to obtain a semi-finished flat strip.

[0092] Embodiment 17

[0093] The difference between this embodiment and embodiment 1 is that the material rod is directly subjected to a round flattening operation to be rolled to a thickness of 3 mm and a width of 15 mm, and then rolled to obtain a semi-finished flat strip.

[0094] Embodiment 18

[0095] The difference between this embodiment and embodiment 1 is that the rolled semi-finished flat strip is subjected to re-annealing treatment, the annealing temperature is 700° C., and the heat preservation time is 3 hours.

[0096] Embodiment 19

[0097] The difference between this embodiment and embodiment 1 is that the rolled semi-finished flat strip is subjected to re-annealing treatment, the annealing temperature is 800° C., and the heat preservation time is 3 hours.

[0098] Embodiment 20

[0099] The difference between this embodiment and embodiment 1 is that the finely drawn flat strip is subjected to online annealing at a temperature of 700° C. and a stepping speed of 5 m / min, and is then rolled up to obtain a finished flat strip.

[0100] Embodiment 21

[0101] The difference between this embodiment and embodiment 1 is that the finely drawn flat strip is subjected to online annealing at an annealing temperature of 800° C. and a stepping speed of 10 m / min, and is then rolled up to obtain a finished flat strip.

[0102] Experimental example

[0103] The CuMn flat strips prepared in each embodiment were divided into experimental samples of equal size, and their performances were tested respectively. The specific research is as follows:

[0104] 1. Explore the effects of different ratios of electrolytic copper plate, nickel plate and electrolytic manganese on the prepared CuMn flat strip. Using Examples 1, 2 and 3 as experimental comparisons, the results are shown in Tables 1 and 2 below:

[0105] Table 1: Chemical composition content of each sample in Examples 1 to 3

[0106]

[0107]

[0108] Table 2: Performance test table of each sample in Examples 1 to 3

[0109]

[0110] Conclusion: It can be seen from the data in Tables 1 and 2 above that the ratio of electrolytic copper plate, nickel plate and electrolytic manganese has a certain influence on the performance of CuMn flat strip. The resistivity of Example 1 is the lowest, and the resistance temperature coefficient of Example 2 is the highest. In terms of comprehensive performance comparison, Example 1 is the best.

[0111] 2. Explore the effects of different parameters of vacuum melting and casting on the prepared CuMn flat strip. Using Examples 1, 4, and 5 as experimental comparisons, the results are shown in Table 3 below:

[0112] Table 3: Performance test table of samples in Examples 1, 4 and 5

[0113]

[0114] Conclusion: From the results in Table 3, it can be seen that different parameters of vacuum melting and casting have a certain influence on the resistivity of the prepared CuMn flat strip and the copper thermoelectric potential, and by comparison, it can be seen that Example 1 has the best comprehensive performance.

[0115] 3. Investigate the influence of different forging parameters on the prepared CuMn flat strip. Take Examples 1, 6, and 7 as experimental comparisons, and the results are shown in Table 4 below:

[0116] Table 4: Performance test table of samples in Examples 1, 6 and 7

[0117]

[0118] Conclusion: From the results in Table 4, it can be seen that different forging parameters have little effect on the resistivity of the prepared CuMn flat strip, but by comparison, Example 1 is relatively better.

[0119] 4. The effects of different hot rolling treatment parameters on the prepared CuMn flat strip were investigated. Examples 1, 8, and 9 were used as experimental comparisons, and the results are shown in Table 5 below:

[0120] Table 5: Performance test table of samples in Examples 1, 8 and 9

[0121]

[0122]

[0123] Conclusion: From the results in Table 5, it can be seen that different parameters of hot rolling treatment have a certain influence on the resistivity and copper thermoelectric potential of the prepared CuMn flat strip, and by comparison, it can be seen that Example 1 is relatively better.

[0124] 5. The effects of different annealing parameters on the prepared CuMn flat strips were investigated. Examples 1, 12, and 13 were used as experimental comparisons, and the results are shown in Table 6 below:

[0125] Table 6: Performance test table of each sample of Examples 1, 12, and 13

[0126]

[0127] Conclusion: From the results in Table 6, it can be seen that different annealing parameters have no significant effect on the resistivity of the prepared CuMn flat strip, and Example 1 is the best in terms of comprehensive performance comparison.

[0128] 6. The effects of different pickling treatment parameters on the prepared CuMn flat strip were investigated. Examples 1, 14, and 15 were used as experimental comparisons, and the results are shown in Table 7 below:

[0129] Table 7: Performance test table of samples in Examples 1, 14 and 15

[0130]

[0131]

[0132] Conclusion: It can be seen from the results in Table 7 that different parameters of the pickling treatment have no obvious effect on the copper thermoelectric potential of the prepared CuMn flat strip. The resistivity of Example 1 is lower than that of Examples 14 and 15, and the comprehensive performance is the best.

[0133] 7. Investigate the effects of different parameters of online annealing of finished products on the prepared CuMn flat strips. Examples 1, 20, 21 and control example 1 were used as experimental comparisons; the results are shown in Table 8 below:

[0134] Table 8: Performance test table of each sample of Examples 1, 20, 21 and Comparative Example 1

[0135]

[0136] The difference between the comparative example 1 and the embodiment 1 is that the rod material is obtained by non-vacuum flat drawing; the material rod is subjected to conventional rolling and fine drawing to obtain the finished flat strip;

[0137] Conclusion: It can be seen from the results in Table 8 that different parameters of online annealing of the finished product can have a certain influence on the performance of the prepared CuMn flat strip. Compared with Examples 20 and 21, Example 1 has a lower resistivity and the best comprehensive performance; compared with Examples 1, 20 and 21, the resistivity of Control Example 1 is higher, so Example 1 using the method of the present invention is better.

Claims

1. A method for preparing a CuMn flat strip for a horizontal splicing strip, characterized in that: include: S1. Ingredients High-purity electrolytic copper plate, nickel plate, metallic chromium, copper-iron master alloy, industrial silicon and electrolytic manganese are used as raw materials, and the content of Mn is 11% to 13%, the content of Ni is 2% to 3%, the content of Cr is 0.01% to 0.02%, the content of Fe is 0.01% to 0.03%, the content of Si is 0.1% to 0.3%, and the balance of Cu is used to obtain a raw material mixture; S2. Vacuum melting and casting The raw material mixture is loaded into a prefabricated crucible of the medium frequency furnace by a one-time feeding method, the furnace cover is closed, and the furnace is evacuated to P less than or equal to 10Pa; the temperature is raised to 1250°C~1350°C by intermittent heating, and after the raw material mixture is melted, high-purity argon is filled into the furnace body; the raw material melt is refined at 1200°C~1250°C for 3 minutes to obtain a raw material melt; CaO, Al2O3, CaF2 and Na3AlF6 are mixed in any ratio to obtain a mixture; 0.05% of the deoxidizer and 0.05% of the mixture accounting for the weight of the raw material melt are added to the raw material melt, and stirred for 1h~1.5h at a temperature of 1180°C~1220°C, and the speed of the stirring device is 35r / min~45r / min, and then 0.05% of the deoxidizer and 0.05% of the mixture accounting for the weight of the raw material melt are added to the raw material melt and stirred for 0.8h~1h; The casting temperature of the raw material melt is controlled at 1150°C~1200°C, and the casting is started after maintaining the temperature for 30 seconds; a steel mold is used for casting, and shrinkage is compensated 3~5 times to obtain an ingot; S3, Forging The riser and bottom plate of the ingot are sawed, and the surface is turned to be bright; then forging is carried out, and the forging temperature is controlled to be 800℃~900℃, and the temperature is kept for 3 hours to forge into a round bar of φ9.5~φ10.

5. After cooling, the surface of the round bar is turned to obtain a bar material; S4, hot rolling treatment The forged bar is hot rolled at a temperature of 800℃~900℃ for 3h~4h, and a thin bar of φ14.5~φ15.5 is obtained by hot rolling, and then coiled; the coiled bar is turned to ensure that the surface of the bar is smooth and free of oxide inclusions, and the bar is turned to a diameter of φ12.5~φ13.5 to obtain a bar; S5. Post-processing S5-1, drawing, S5-2, annealing the rod after drawing, using hydrogen as the protective atmosphere, controlling the annealing temperature to 700℃~800℃, and keeping it warm for 3h, S5-3, pickling, S5-4, rolling, S5-5, re-annealing, S5-6, fine drawing, S5-7, online annealing of finished products, S5-8, inspection and packaging.

2. The method for preparing a CuMn flat strip for horizontal splicing according to claim 1, characterized in that: Step S5-1: The drawing step is to draw the rod material and control the deformation amount of each process to be less than or equal to 30%.

3. The method for preparing a CuMn flat strip for horizontal splicing according to claim 2, characterized in that: Step S5-3: Pickling step: pickling the annealed rod material to remove the surface oxide scale, the pickling solution is a mixture of 30wt% sulfuric acid, 10wt% nitric acid and the rest water, and after pickling, it is washed with warm water and air-dried to obtain the material; the pickled material is repeatedly drawn, annealed and pickled until the material size reaches φ7.5~φ8.5; the material rod is obtained.

4. The method for preparing a CuMn flat strip for horizontal splicing according to claim 3, characterized in that: The rolling step of step S5-4 is: directly rolling the material rod into a round flat, using a multi-pass rolling method, controlling the deformation ratio of each rolling pass to be within 30%, rolling to a thickness of 1.5mm~3mm, a width of 10mm~15mm, and winding to obtain a semi-finished flat strip.

5. The method for preparing a CuMn flat strip for horizontal splicing according to claim 4, characterized in that: Step S5-5 is a re-annealing step: re-annealing the rolled semi-finished flat strip at a temperature of 700°C to 800°C for 3 hours; pickling the annealed semi-finished flat strip to remove the surface oxide scale, and the pickling solution is a mixture of 30wt% sulfuric acid, 10wt% nitric acid and the remainder water.

6. The method for preparing a CuMn flat strip for horizontal splicing according to claim 5, characterized in that: Step S5-6 is a finishing drawing step: the pickled semi-finished flat strip is drawn using a mold as required to obtain flat strips of one or more specifications of 1.5mm*15mm, 1.5mm*12mm, 1.5mm*11mm, 1mm*11mm, 1mm*12mm or 1mm*15mm.

7. The method for preparing a CuMn flat strip for horizontal splicing according to claim 6, characterized in that: Step S5-7 is the step of online annealing of finished products: the finely drawn flat strip is subjected to online annealing of finished products, the annealing temperature is 700°C to 800°C, the stepping speed is 5m / min to 10m / min, and a winding process is performed to obtain a finished flat strip.

8. The method for preparing a CuMn flat strip for horizontal splicing according to claim 7, characterized in that: Step S5-8 is the inspection and packaging step: sampling and testing the resistivity, temperature coefficient of resistance, hardness, and surface roughness of the finished flat belt; observing the appearance to ensure that the surface is smooth and flat, and packaging and shipping the flat belt that has passed the inspection.

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