Tin-phosphor bronze belt for etching and preparation method of tin-phosphor bronze belt

Abstract

The invention provides a tin-phosphor bronze belt for etching and a preparation method of the tin-phosphor bronze belt. Comprising the following steps of blank casting, annealing, double-face milling, cold rolling cogging, primary recrystallization annealing, thick strip washing, medium rolling deformation, secondary recrystallization annealing, thick strip washing, finish rolling deformation, primary air cushion continuous annealing, bottom rolling, secondary air cushion continuous annealing, finish rolling deformation, tertiary air cushion continuous annealing and splitting, rolling and warehousing. According to the preparation method of the tin-phosphor bronze strip for etching, the tensile strength of the tin-phosphor bronze strip for etching is 600-625 MPa, the yield strength is 550-585 MPa, the Vickers hardness is 195-210 HV, the ductility is 25-30%, the flexural height is 1-2 mm, the grain size is 1-3 microns, and the standard deviation is 0.56-1.26 through large-deformation cold rolling cogging and in combination with an intermediate recrystallization annealing process and an air cushion annealing process. And the application of the tin-phosphor bronze belt for etching a vapor chamber and the like can be met.

Description

Technical Field

[0001] The invention relates to the technical field of processing special-shaped copper strips, and in particular to a tin-phosphor bronze strip for etching and a preparation method thereof. Background Art

[0002] With the development of 5G technology, electronic products, especially smartphones and tablets, are moving towards high performance, high integration and miniaturization. This leads to ultra-high heat flux density in extremely small spaces. As an efficient heat transfer element, the heat spreader has the characteristics of low thermal resistance and uniform temperature, and is widely used in the heat dissipation module of high heat flux density equipment. Compared with traditional radiators, the heat spreader has higher heat dissipation performance, and the thermal conductivity is 20% to 30% higher than that of heat pipes, which can better meet the needs of miniaturized electronic devices in the 5G era. As one of the materials for the heat spreader, the tin-phosphor bronze strip often has the problem of plate warping and deformation caused by large internal residual stress after etching. How to ensure that the tin-phosphor bronze strip has small residual stress and good plate shape is a difficult problem that the heat spreader material needs to solve. However, the current tin-phosphor bronze products are difficult to meet the requirements of having small residual stress and excellent plate shape at the same time, so as to meet the further requirements of increasing heat dissipation due to power consumption and structural changes of electronic products. Based on this, the present invention provides a preparation method of tin-phosphor bronze strip for etching, which solves the contradiction between the synergistic improvement of residual stress and good plate shape of tin-phosphor bronze strip. Summary of the invention

[0003] In view of this, the present invention proposes a method for preparing a tin-phosphor bronze strip for etching to solve the problem in the prior art that the tin-phosphor bronze strip has large internal residual stress and poor plate shape, resulting in warping and deformation of the plate after etching.

[0004] The technical solution of the present invention is achieved as follows: The present invention provides a method for preparing a tin-phosphor bronze strip for etching, the preparation method comprising the following steps:

[0005] Step S1: homogenizing and annealing the ingot and performing double-sided milling to obtain an initial ingot;

[0006] Step S2: cold rolling the initial blank for 8 passes to obtain a 2.5 mm cold rolled blank, and then performing thick strip washing after the first intermediate recrystallization annealing to obtain a cold rolled blank;

[0007] Step S3: performing intermediate rolling deformation on the cold rolled blank, the intermediate rolling deformation passes are 3 passes, and an intermediate blank of 1.0 mm is obtained. After the second intermediate recrystallization annealing, thick strip washing is performed to obtain an intermediate blank;

[0008] Step S4: performing finish rolling deformation on the intermediate billet, the number of finish rolling deformation passes is 3, a finish rolling billet amount of 0.4 mm is obtained, and the first air cushion continuous annealing is performed to obtain a finish rolling billet;

[0009] Step S5: performing bottom rolling on the finished rolled billet, the bottom rolling passes are 2, and performing a second air cushion continuous annealing to obtain a bottom rolled billet;

[0010] Step S6: rolling the bottom blank into finished product, with one rolling pass, and performing a third air cushion continuous annealing to obtain a finished product;

[0011] Step S7: the finished material is divided into strips, rolled up and stored to obtain tin-phosphor bronze strips for etching.

[0012] On the basis of the above technical solution, preferably, in step S1, the ingot is prepared by horizontal continuous casting of tin-phosphorus bronze raw material; the tin content of the tin-phosphorus bronze raw material is 5.7-6.7%, and the phosphorus content is 0.1-0.25%; the thickness of the ingot is 14-15 mm.

[0013] On the basis of the above technical solution, preferably, in the step S1, the tin content in the tin-phosphor bronze raw material is independently selected from any value of 5.7%, 5.8%, 6%, 6.2%, 6.5%, 6.7% or a range between any two of the above.

[0014] On the basis of the above technical solution, preferably, in the step S1, the phosphorus content in the tin-phosphorus bronze raw material is independently selected from any value among 0.1%, 0.13%, 0.15%, 0.18%, 0.23%, 0.25% or a range between any two of the above.

[0015] On the basis of the above technical solution, preferably, in step S1, the thickness of the ingot is independently selected from any value among 14 mm, 14.2 mm, 14.4 mm, 14.5 mm, 14.6 mm, 14.8 mm, 15 mm or a range value between any two of the above.

[0016] On the basis of the above technical solution, preferably, in step S2, the rolling process of 8 passes is 14.5-12-9.8-7.9-6.3-4.8-3.7-2.9-2.5mm;

[0017] The heating temperature of the first intermediate recrystallization annealing is 510-540° C., and the holding time is 5-7 hours.

[0018] On the basis of the above technical solution, preferably, in step S3, the rolling process of three passes is 2.5-1.7-1.3-1.0 mm;

[0019] The heating temperature of the second intermediate recrystallization annealing is 460-480° C., and the holding time is 5-7 hours.

[0020] On the basis of the above technical solution, preferably, in step S4, the rolling process of the three passes is 1.0-0.7-0.5-0.4 mm;

[0021] The temperature of the first air cushion continuous annealing is 490-520° C., and the holding time is 20-40 seconds.

[0022] On the basis of the above technical solution, preferably, in step S5, the rolling process of the two passes is 0.4-0.32-0.27 mm;

[0023] The temperature of the second air cushion continuous annealing is 490-510° C., and the holding time is 20-40 seconds.

[0024] On the basis of the above technical solution, preferably, in step S6, the rolling deformation amount of one pass is 5-10%.

[0025] On the basis of the above technical solution, preferably, in the step S6, the temperature of the third air cushion continuous annealing is 440-460° C., and the holding time is 50-80 s.

[0026] On the basis of the above technical solution, preferably, in the step S7, the blade gap of the vacuum roller slitting shearing machine used for the slitting is 40-60% of the thickness of the finished material.

[0027] According to another aspect of the present application, a tin-phosphorus bronze strip for etching prepared by the above-mentioned preparation method is provided, wherein the tin-phosphorus bronze strip for etching has a tensile strength of 600-625 MPa, a yield strength of 550-585 MPa, a Vickers hardness of 195-210 HV, an elongation of 25-30%, a deflection height of 1-2 mm, a grain size of 1-3 μm, and a standard deviation of 0.56-1.26.

[0028] As an optional implementation method, the present application is implemented through the following technical solutions:

[0029] The present invention provides a method for preparing a tin-phosphor bronze strip for etching, comprising the following steps:

[0030] Step S1: Preparation of tin-phosphor bronze billet: homogenizing annealing and double-sided milling of the billet obtained by horizontal continuous casting to obtain an initial billet for cold rolling;

[0031] Step S2: preparing cold-rolled blanks: cold-rolling the initial blanks in step S1 for 8 passes to obtain a 2.5 mm cold-rolled blank, and then performing the first intermediate recrystallization annealing and thick strip washing;

[0032] Step S3: intermediate billet preparation: the cold rolled billet obtained in step S2 is subjected to intermediate rolling deformation, the intermediate rolling deformation passes are 3 passes, and a 1.0 mm intermediate billet is obtained, and a second intermediate recrystallization annealing is performed and then thick strip washing is performed;

[0033] Step S4: Preparation of finished rolled billet: The intermediate billet obtained in step S3 is subjected to finish rolling deformation, the number of finish rolling deformation passes is 3, and a 0.4 mm finished rolled billet is obtained, and the first air cushion continuous annealing furnace annealing is performed;

[0034] Step S5: Preparation of bottom billet: The finished rolled billet obtained in step S4 is subjected to bottom rolling, the bottom rolling passes are 2 passes, and the second air cushion continuous annealing furnace annealing is performed;

[0035] Step S6: Finished product preparation: The bottom billet obtained in step S5 is subjected to finished product rolling, with one rolling pass, and annealed in the air cushion continuous annealing furnace for the third time;

[0036] Step S7: Slitting and warehousing: the finished material obtained in step S6 is slit on a vacuum roller slitting shearing machine, with the knife gap being 40-60% of the strip thickness, and then rolled up and stored.

[0037] The present invention performs cold rolling, intermediate rolling deformation, and finish rolling deformation on the initial billet for cold rolling, and then performs bottom rolling and finished product rolling, and then stores the billet in strips. After cold rolling, the first intermediate recrystallization annealing is required, and then thick strip washing is performed. The purpose of cold rolling is to break the tin bronze billet structure with a coarse grain structure, and the introduced dislocation and deformation energy storage lay the foundation for subsequent recrystallization annealing to obtain a uniform and fine grain structure. The purpose of performing the first intermediate recrystallization annealing and thick strip washing after cold rolling is to recrystallize the structure after the previous cold rolling, so that the dislocation inside the tin bronze strip is rearranged, the stress concentration and plastic deformation generated during the cold rolling process are eliminated, and the plasticity of the material is restored, which is convenient for subsequent processing; at the same time, recrystallization allows new grains to replace the deformed old grains, and these new grains are usually finer than the original grains, thereby improving the strength and toughness of the material; at the same time, the microscopic inhomogeneity inside the material can be eliminated, such as uneven grain deformation and uneven dislocation density, so that the structure is more uniform. In order to ensure that the structure is fine and uniform and recrystallization has occurred, the annealing temperature is finally controlled at 510-540°C and the holding time is controlled at 5-7h.

[0038] Then, intermediate rolling deformation and the second intermediate recrystallization annealing are carried out, and then thick strip washing is carried out. Among them, the intermediate rolling deformation is to further refine the structure, so that the structure of the previous process is further broken, laying the foundation for the subsequent structure to become more uniform and fine. The thick strip washing after the second intermediate recrystallization annealing is to carry out recrystallization annealing on the basis of finer structure crushing, and control the growth of new grains to be smaller than the original old grains. Therefore, the annealing temperature is finally controlled at 460-480°C, and the holding time is controlled at 5-7h.

[0039] Then, the billet after the second intermediate recrystallization annealing is subjected to finishing deformation and the first air cushion continuous annealing furnace annealing. The finishing deformation is used to further deform and refine the grains of the billet after the second intermediate recrystallization annealing, and considering the corresponding deformation energy storage, the deformation amount and annealing are coordinated and controlled. The first air cushion continuous annealing furnace is used for annealing. The first air cushion continuous annealing is used. The annealing temperature is 490-520°C and the holding time is 20-40s. During the air cushion continuous annealing, the material continuously enters the furnace at a constant speed to achieve continuous annealing, and the atmosphere gas in the furnace is controlled to reduce material oxidation. When the annealing temperature is less than 490°C, the strip cannot achieve the required annealing during this holding time, and the grain structure does not undergo complete recrystallization, and the purpose of annealing cannot be achieved. When the annealing temperature is greater than 520°C, due to the relatively high temperature, the grain structure is prone to grow during this holding time, resulting in the grain structure not achieving the purpose of further refinement.

[0040] The finished rolled billet is subjected to bottom rolling and second air cushion continuous annealing furnace annealing. The purpose of bottom rolling is to control the rolling deformation of the final finished product state, and at the same time, the deformation of bottom rolling can provide sufficient deformation energy storage, so that complete recrystallization annealing can be obtained during the second air cushion continuous annealing, and the grain structure can be further refined; the temperature of the second air cushion continuous annealing is 490-510°C, and the holding time is 20-40s. The purpose of the second air cushion continuous annealing is to ensure that the structure is further fine and uniform, and no growth occurs. When the annealing temperature is less than 490°C and greater than 510°C, the purpose of uniform and fine structure and complete recrystallization cannot be achieved.

[0041] The remaining blank is subjected to finished product rolling and annealing in the third air cushion continuous annealing furnace. The purpose of finished product rolling is to ensure that the strip can improve its strength through fine grain strengthening, and cannot be deformed too much to affect the internal stress of the strip. The temperature of the third air cushion continuous annealing is 440-460°C, and the holding time is 50-80s. When the annealing temperature is less than 440°C, the purpose of removing internal stress cannot be achieved, and the plate shape of the strip cannot be controlled. When it is greater than 460°C, the strength requirement cannot be met due to softening of the organization, and thus it is impossible to obtain a strip with sufficient strength and low internal stress.

[0042] The method for preparing the tin-phosphor bronze strip for etching of the present invention has the following beneficial effects compared with the prior art:

[0043] The tin-phosphor bronze raw material of the present application is subjected to large deformation cold rolling to open the blank, so that the cast structure can be broken, and the grain size is controlled to a smaller size by combining the control of two intermediate recrystallization annealing and three air cushion continuous annealing processes; at the same time, the cold deformation and heat treatment processes in each processing stage are coordinated to make the grains finer and more uniform, which is conducive to the etching of tin-phosphor bronze, and at the same time, the warping height of the tin-phosphor bronze strip after etching is greatly improved, and the processing rate of tin-phosphor bronze in the finished state is controlled to ensure that the plate shape of the tin-phosphor bronze strip is well controlled, and the generation of internal residual stress is reduced. Then, under the synergistic effect of small internal residual stress and uniform and fine grain structure, the tin-phosphor bronze strip has excellent etching performance, and the warping height of the tin-phosphor bronze strip after etching is reduced as much as possible, thereby solving the contradiction between the synergistic improvement of the residual stress of the tin-phosphor bronze strip and the good plate shape. Among them, during the air cushion continuous annealing, the material can continuously enter the air cushion furnace at a constant speed to achieve continuous annealing, and the atmosphere gas in the furnace is controlled to reduce material oxidation.

[0044] The tin-phosphor bronze strip for etching prepared by the present invention has a tensile strength of 600-625 MPa, a yield strength of 550-585 MPa, a Vickers hardness of 195-210 HV, an elongation of 25-30%, a deflection height of 1-2 mm, a grain size of 1-3 μm, and a standard deviation of 0.56-1.26. Compared with the prior art, the preparation method of the present invention not only has good plate shape control and low residual stress, but also has a fine and uniform grain structure, can meet the requirements of tin-phosphor bronze strips for etching such as heat spreaders, has been widely used in the field of etching, and has significant economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0046] Figure 1 The tin-phosphor bronze strip obtained in Example 1 of the present invention has a uniform and fine grain structure;

[0047] Figure 2 The grain size distribution result of the tin-phosphor bronze strip obtained in Example 1 of the present invention;

[0048] Figure 3The warping condition of the tin-phosphor bronze strip obtained in Example 1 of the present invention after etching. DETAILED DESCRIPTION

[0049] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] Example 1

[0051] The composition of the tin-phosphor bronze strip of Example 1 is shown in Table 1, and the performance test results are shown in Table 2, which are as follows:

[0052] Step S1: homogenizing annealing and double-sided milling of the ingot prepared by horizontal continuous casting of tin-phosphor bronze raw materials to obtain an initial ingot for cold rolling;

[0053] Step S2: cold rolling the initial blank, the number of cold rolling passes is 8, the process is 14.5-12-9.8-7.9-6.3-4.8-3.7-2.9-2.5mm, and a cold rolled blank of 2.5mm is obtained. The first intermediate recrystallization annealing is performed, the annealing heating temperature is 520°C, the holding time is 6h, and then the thick strip is washed to obtain a cold rolled blank;

[0054] Step S3: the cold rolled blank is subjected to intermediate rolling deformation, the intermediate rolling deformation passes are 3 passes, the process is 2.5-1.7-1.3-1.0, and a 1.0 mm intermediate blank is obtained, and a second intermediate recrystallization annealing is performed, the heating temperature is 480° C., the holding time is 5 h, and then the thick strip is washed to obtain an intermediate rolling deformed blank;

[0055] Step S4: performing finish rolling deformation on the intermediate rolled deformed billet, the finish rolling deformation passes are 3 passes, the process is 1.0-0.7-0.5-0.4mm, and a 0.4mm finish rolled billet is obtained, and the first air cushion continuous annealing furnace annealing is performed, the annealing temperature is 510°C, and the holding time is 30s to obtain a finish rolled billet;

[0056] Step S5: performing bottom rolling on the finished rolled billet, the bottom rolling passes are 2 passes, the process is 0.4-0.32-0.27mm, and performing a second air cushion continuous annealing furnace annealing, the annealing temperature is 500°C, and the holding time is 30s to obtain a bottom rolling billet;

[0057] Step S6: rolling the bottom blank into finished product, with one rolling pass and a rolling deformation of 7%, and performing a third air cushion continuous annealing furnace annealing at a temperature of 450° C. and a holding time of 60 seconds;

[0058] Step S7: Slit the finished material on a vacuum roller slitting shearing machine, with the knife gap being 50% of the strip thickness, and then rolled up and stored to obtain a tin-phosphor bronze strip with mechanical properties, grain size and deflection height that meet the requirements. The specific experimental results are shown in Table 2. Figure 1 As shown, Figure 1 It can be seen that the grain structure is uniform and fine, without coarse structure; Figure 2 It can be seen that the average grain size is 1 μm, the grain structure shows a normal distribution, and the average standard deviation is 0.56 μm, which is also consistent with Figure 1 Corresponding to the organization in Figure 3 It can be seen that the warping of the strip after etching is very small, only 1mm, which fully meets the requirements of tin phosphor bronze strip for etching.

[0059] Example 2

[0060] The composition of the tin-phosphor bronze strip of Example 2 is shown in Table 1, and the performance test results are shown in Table 2, which are as follows:

[0061] Step S1: homogenizing annealing and double-sided milling of the ingot prepared by horizontal continuous casting of tin-phosphor bronze raw materials to obtain an initial ingot for cold rolling;

[0062] Step S2: cold rolling the initial blank, the number of cold rolling passes is 8, the process is 14.5-12-9.8-7.9-6.3-4.8-3.7-2.9-2.5mm, and a cold rolled blank of 2.5mm is obtained. The first intermediate recrystallization annealing is performed, the annealing heating temperature is 530°C, the holding time is 5.5h, and then the thick strip is washed to obtain a cold rolled blank;

[0063] Step S3: the cold rolled blank is subjected to intermediate rolling deformation, the intermediate rolling deformation passes are 3 passes, the process is 2.5-1.7-1.3-1.0, and a 1.0 mm intermediate blank is obtained, and a second intermediate recrystallization annealing is performed, the heating temperature is 465° C., the holding time is 6.5 h, and then the thick strip is washed to obtain an intermediate rolling deformed blank;

[0064] Step S4: performing finish rolling deformation on the intermediate rolled deformed billet, the finish rolling deformation passes are 3 passes, the process is 1.0-0.7-0.5-0.4mm, and a 0.4mm finish rolled billet is obtained, and the first air cushion continuous annealing furnace annealing is performed, the annealing temperature is 490°C, and the holding time is 40s to obtain a finish rolled billet;

[0065] Step S5: performing bottom rolling on the finished rolled billet, the bottom rolling passes are 2 passes, the process is 0.4-0.32-0.27mm, and performing a second air cushion continuous annealing furnace annealing, the annealing temperature is 490°C, and the holding time is 40s to obtain a bottom rolling billet;

[0066] Step S6: rolling the bottom blank into finished product, with one rolling pass and a rolling deformation of 5%, and performing the third air cushion continuous annealing furnace annealing, with an annealing temperature of 460° C. and a holding time of 50 s;

[0067] Step S7: Slit the finished material on a vacuum roller slitting shearing machine with a knife gap of 40% of the strip thickness, and store it after winding to obtain a tin-phosphor bronze strip with mechanical properties, grain size and deflection height that meet the requirements. The specific experimental results are shown in Table 2.

[0068] Example 3

[0069] The composition of the tin-phosphor bronze strip of Example 3 is shown in Table 1, and the performance test results are shown in Table 2, which are as follows:

[0070] Step S1: homogenizing annealing and double-sided milling of the ingot prepared by horizontal continuous casting of tin-phosphor bronze raw materials to obtain an initial ingot for cold rolling;

[0071] Step S2: cold rolling the initial blank, the number of cold rolling passes is 8, the process is 14.5-12-9.8-7.9-6.3-4.8-3.7-2.9-2.5mm, and a cold rolled blank of 2.5mm is obtained. The first intermediate recrystallization annealing is performed, the annealing heating temperature is 510°C, the holding time is 7h, and then the thick strip is washed to obtain a cold rolled blank;

[0072] Step S3: the cold rolled blank is subjected to intermediate rolling deformation, the intermediate rolling deformation passes are 3 passes, the process is 2.5-1.7-1.3-1.0, and a 1.0 mm intermediate blank is obtained, and a second intermediate recrystallization annealing is performed, the heating temperature is 470° C., the holding time is 6 h, and then the thick strip is washed to obtain an intermediate rolling deformed blank;

[0073] Step S4: performing finish rolling deformation on the intermediate rolled deformed billet, the finish rolling deformation passes are 3 passes, the process is 1.0-0.7-0.5-0.4mm, and a 0.4mm finish rolled billet is obtained, and the first air cushion continuous annealing furnace annealing is performed, the annealing temperature is 500°C, and the holding time is 35s to obtain a finish rolled billet;

[0074] Step S5: performing bottom rolling on the finished billet, the bottom rolling passes are 2 passes, the process is 0.4-0.32-0.27mm, and performing a second air cushion continuous annealing furnace annealing, the annealing temperature is 495°C, and the holding time is 25s to obtain a bottom billet;

[0075] Step S6: rolling the bottom blank into finished product, with one rolling pass and a rolling deformation of 10%, and performing the third air cushion continuous annealing furnace annealing, with an annealing temperature of 440° C. and a holding time of 80 seconds;

[0076] Step S7: Slit the finished material on a vacuum roller slitting shearing machine, with the knife gap being 60% of the strip thickness, and then rolled up and stored to obtain a tin-phosphor bronze strip with mechanical properties, grain size and deflection height that meet the requirements. The specific experimental results are shown in Table 2.

[0077] Example 4

[0078] The composition of the tin-phosphor bronze strip of Example 4 is shown in Table 1, and the performance test results are shown in Table 2, which are as follows:

[0079] Step S1: homogenizing annealing and double-sided milling of the ingot prepared by horizontal continuous casting of tin-phosphor bronze raw materials to obtain an initial ingot for cold rolling;

[0080] Step S2: cold rolling the initial blank, the number of cold rolling passes is 8, the process is 14.5-12-9.8-7.9-6.3-4.8-3.7-2.9-2.5mm, and a cold rolled blank of 2.5mm is obtained. The first intermediate recrystallization annealing is performed, the annealing heating temperature is 540°C, the holding time is 5h, and then the thick strip is washed to obtain a cold rolled blank;

[0081] Step S3: the cold rolled blank is subjected to intermediate rolling deformation, the intermediate rolling deformation passes are 3 passes, the process is 2.5-1.7-1.3-1.0, and a 1.0 mm intermediate blank is obtained, and a second intermediate recrystallization annealing is performed, the heating temperature is 460° C., the holding time is 7 hours, and then the thick strip is washed to obtain an intermediate rolling deformed blank;

[0082] Step S4: performing finish rolling deformation on the intermediate rolled deformed billet, the finish rolling deformation passes are 3 passes, the process is 1.0-0.7-0.5-0.4mm, and a 0.4mm finish rolled billet is obtained, and the first air cushion continuous annealing furnace annealing is performed, the annealing temperature is 520°C, and the holding time is 20s to obtain a finish rolled billet;

[0083] Step S5: performing bottom rolling on the finished billet, the bottom rolling passes are 2 passes, the process is 0.4-0.32-0.27mm, and performing a second air cushion continuous annealing furnace annealing, the annealing temperature is 510°C, and the holding time is 20s to obtain a bottom billet;

[0084] Step S6: rolling the bottom blank into finished product, with one rolling pass and a rolling deformation of 8%, and performing the third air cushion continuous annealing furnace annealing, with an annealing temperature of 455° C. and a holding time of 70 seconds;

[0085] Step S7: Slit the finished material on a vacuum roller slitting shearing machine, with the knife gap being 55% of the strip thickness, and then rolled up and stored to obtain a tin-phosphor bronze strip with mechanical properties, grain size and deflection height that meet the requirements. The specific experimental results are shown in Table 2.

[0086] Comparative Example 1

[0087] The composition of the tin-phosphor bronze strip of Comparative Example 1 is shown in Table 1, and the performance test results are shown in Table 2, which are as follows:

[0088] Step S1: homogenizing annealing and double-sided milling of the ingot prepared by horizontal continuous casting of tin-phosphor bronze raw materials to obtain an initial ingot for cold rolling;

[0089] Step S2: cold rolling the initial blank, the number of cold rolling passes is 8, the process is 14.5-12-9.8-7.9-6.3-4.8-3.7-2.9-2.5mm, and a cold rolled blank of 2.5mm is obtained. The first intermediate recrystallization annealing is performed, the annealing heating temperature is 490°C, the holding time is 7h, and then the thick strip is washed to obtain a cold rolled blank;

[0090] Step S3: the cold rolled blank is subjected to intermediate rolling deformation, the intermediate rolling deformation passes are 3 passes, the process is 2.5-1.7-1.3-1.0, and a 1.0 mm intermediate blank is obtained, and a second intermediate recrystallization annealing is performed, the heating temperature is 450° C., the holding time is 7 hours, and then the thick strip is washed to obtain an intermediate rolling deformed blank;

[0091] Step S4: performing finish rolling deformation on the intermediate rolled deformed billet, the finish rolling deformation passes are 3 passes, the process is 1.0-0.7-0.5-0.4mm, and a 0.4mm finish rolled billet is obtained, and the first air cushion continuous annealing furnace annealing is performed, the annealing temperature is 540°C, and the holding time is 10s to obtain a finish rolled billet;

[0092] Step S5: performing bottom rolling on the finished billet, the bottom rolling passes are 2 passes, the process is 0.4-0.32-0.27mm, and performing a second air cushion continuous annealing furnace annealing, the annealing temperature is 520°C, and the holding time is 20s to obtain a bottom billet;

[0093] Step S6: rolling the bottom blank into finished product, with one rolling pass and a rolling deformation of 3%, and performing a third air cushion continuous annealing furnace annealing at a temperature of 430° C. and a holding time of 80 seconds;

[0094] Step S7: Slit the finished material on a vacuum roller slitting shearing machine, with the knife gap being 30% of the strip thickness, and then coiled and stored. The tin-phosphor bronze strip with mechanical properties, grain size and deflection height meeting the requirements is obtained.

[0095] Comparative Example 2

[0096] The composition of the tin-phosphor bronze strip of Comparative Example 2 is shown in Table 1, and the performance test results are shown in Table 2, which are as follows:

[0097] Step S1: homogenizing annealing and double-sided milling of the ingot prepared by horizontal continuous casting of tin-phosphor bronze raw materials to obtain an initial ingot for cold rolling;

[0098] Step S2: cold rolling the initial blank, the number of cold rolling passes is 8, the process is 14.5-12-9.8-7.9-6.3-4.8-3.7-2.9-2.5mm, and a cold rolled blank of 2.5mm is obtained. The first intermediate recrystallization annealing is performed, the annealing heating temperature is 560°C, the holding time is 5h, and then the thick strip is washed to obtain a cold rolled blank;

[0099] Step S3: the cold rolled blank is subjected to intermediate rolling deformation, the intermediate rolling deformation passes are 3 passes, the process is 2.5-1.7-1.3-1.0, and a 1.0 mm intermediate blank is obtained, and a second intermediate recrystallization annealing is performed, the heating temperature is 500° C., the holding time is 5 h, and then the thick strip is washed to obtain an intermediate rolling deformed blank;

[0100] Step S4: performing finish rolling deformation on the intermediate rolled deformed billet, the finish rolling deformation passes are 3 passes, the process is 1.0-0.7-0.5-0.4mm, and a 0.4mm finish rolled billet is obtained, and the first air cushion continuous annealing furnace annealing is performed, the annealing temperature is 480°C, and the holding time is 50s to obtain a finish rolled billet;

[0101] Step S5: performing bottom rolling on the finished rolled billet, the bottom rolling passes are 2 passes, the process is 0.4-0.32-0.27mm, and performing a second air cushion continuous annealing furnace annealing, the annealing temperature is 480°C, and the holding time is 40s to obtain a bottom rolling billet;

[0102] Step S6: rolling the bottom blank into finished product, with one rolling pass and a rolling deformation of 15%, and performing the third air cushion continuous annealing furnace annealing, with an annealing temperature of 480° C. and a holding time of 50 s;

[0103] Step S7: Slit the finished material on a vacuum roller slitting shearing machine, with the knife gap being 70% of the strip thickness, and then rolled up and stored to obtain a tin-phosphor bronze strip with mechanical properties, grain size and deflection height that meet the requirements. The specific experimental results are shown in Table 2.

[0104] Comparative Example 3

[0105] In Example 1, the number of cold rolling blanking passes in step S2 is adjusted to 6 passes, the process is 14.5-11-9-7-5-3-2.5mm, and a cold rolled blank amount of 2.5mm is obtained. The first intermediate recrystallization annealing is performed, the annealing heating temperature is 520°C, the holding time is 6h, and then the thick strip is washed to obtain a cold rolled blank. The remaining preparation steps are consistent with those in Example 1. The specific experimental results of the obtained tin-phosphor bronze strip are shown in Table 2.

[0106] Comparative Example 4

[0107] In Example 1, the intermediate rolling deformation passes in step S3 are adjusted to 2 passes, the process is 2.5-1.5-1.0 mm, and a 1.0 mm intermediate billet is obtained. The second intermediate recrystallization annealing is performed, the heating temperature is 480°C, the holding time is 5 h, and then the thick strip is washed to obtain an intermediate rolling deformation billet. The remaining preparation steps are consistent with those in Example 1. The specific experimental results of the obtained tin-phosphor bronze strip are shown in Table 2.

[0108] Comparative Example 5

[0109] In Example 1, the finishing deformation passes in step S4 are adjusted to 2 passes, the process is 1.0-0.6-0.4mm, and a 0.4mm finishing billet is obtained. The first air cushion continuous annealing furnace annealing is performed, the annealing temperature is 510°C, and the holding time is 30s to obtain a finishing billet. The remaining preparation steps are consistent with those in Example 1. The specific experimental results of the obtained tin-phosphor bronze strip are shown in Table 2.

[0110] Comparative Example 6

[0111] In Example 1, step S4 is adjusted to subject the intermediate rolled deformed billet to finish rolling deformation, the finishing rolling deformation passes are 3 passes, the process is 1.0-0.7-0.5-0.4mm, and a 0.4mm finished rolled billet is obtained. The first air cushion furnace annealing is performed, the annealing temperature is 550°C, and the holding time is 40s to obtain a finished rolled billet. The remaining preparation steps are consistent with those in Example 1. The specific experimental results of the obtained tin-phosphor bronze strip are shown in Table 2.

[0112] Comparative Example 7

[0113] In Example 1, step S5 is adjusted to perform bottom rolling on the finished rolled billet, the bottom rolling passes are 2 passes, the process is 0.4-0.32-0.27mm, and the second air cushion furnace annealing is performed, the annealing temperature is 450°C, and the holding time is 60s to obtain a bottom billet. The remaining preparation steps are consistent with those in Example 1. The specific experimental results of the obtained tin-phosphor bronze strip are shown in Table 2.

[0114] Comparative Example 8

[0115] In Example 1, step S6 is adjusted to roll the bottom blank into finished product, the rolling pass is 1 pass, the rolling deformation is 7%, and the third air cushion furnace annealing is performed, the annealing temperature is 420° C., and the holding time is 90 s. The remaining preparation steps are consistent with those in Example 1. The specific experimental results of the obtained tin-phosphor bronze strip are shown in Table 2.

[0116] Comparative Example 9

[0117] In Example 1, step S4 is adjusted to subject the intermediate rolled deformed billet to finish rolling deformation, the finishing rolling deformation passes are 3 passes, the process is 1.0-0.7-0.5-0.4mm, a 0.4mm finished rolled billet is obtained, and the first air cushion furnace annealing is performed, the annealing temperature is 480°C, and the holding time is 50s to obtain a finished rolled billet;

[0118] Step S5 is adjusted to perform bottom rolling on the finished billet, the bottom rolling passes are 2 passes, the process is 0.4-0.32-0.27mm, and the second air cushion furnace annealing is performed, the annealing temperature is 480°C, and the holding time is 60s to obtain a bottom billet; the remaining preparation steps are consistent with those in Example 1, and the specific experimental results of the obtained tin-phosphor bronze strip are shown in Table 2.

[0119] Comparative Example 10

[0120] In Example 1, step S4 is adjusted to subject the intermediate rolled deformed billet to finish rolling deformation, the finishing rolling deformation passes are 3 passes, the process is 1.0-0.7-0.5-0.4mm, a 0.4mm finished rolled billet is obtained, and the first air cushion furnace annealing is performed, the annealing temperature is 530°C, and the holding time is 50s to obtain a finished rolled billet;

[0121] Step S6 is adjusted to roll the bottom blank into finished product, with 1 rolling pass and 5% rolling deformation, and the third air cushion furnace annealing is performed, with the annealing temperature being 480°C and the holding time being 90s; the remaining preparation steps are consistent with those in Example 1, and the specific experimental results of the obtained tin-phosphor bronze strip are shown in Table 2.

[0122] Table 1 Compositions of the embodiments of the present invention and comparative examples.

[0123] Table 1

[0124] Element Sn P Example 1 6.5 0.13 Example 2 6 0.18 Example 3 6.7 0.25 Example 4 5.7 0.1 Comparative Example 1 6.5 0.13 Comparative Example 2 5.7 0.1 Comparative Example 3 6.5 0.13 Comparative Example 4 6.5 0.13 Comparative Example 5 6.5 0.13 Comparative Example 6 6.5 0.13 Comparative Example 7 6.5 0.13 Comparative Example 8 6.5 0.13 Comparative Example 9 6.5 0.13 Comparative Example 10 6.5 0.13

[0125] Test Example 1

[0126] The mechanical properties test is carried out on an electronic universal mechanical properties testing machine in accordance with GB / T 228.1-2021 Tensile tests on metallic materials Part 1: Room temperature test method, using a standard dumbbell-shaped specimen for stretching.

[0127] Vickers hardness test is carried out on a Vickers hardness tester in accordance with GB / T 4340.1-1999: Metal Vickers hardness test method Part 1: Test method.

[0128] The deflection height test is carried out on the tin phosphor bronze strip in accordance with YS / T 1678-2023 "Test Method for Residual Stress of Copper and Copper Alloy Plates, Strips and Foils - Etching Strip Method".

[0129] The grain size and standard deviation test was conducted by scanning electron microscope EBSD analysis, and the cross-sectional structure (longitudinal section) of the finished sample along the rolling direction was magnified 5000 times for observation. The average grain size and standard deviation of the sample were tested by OIM8.0 analysis software to judge the grain size and grain uniformity distribution of the sample.

[0130] Table 2 Performance of the Examples of the Invention and Comparative Examples

[0131]

[0132]

[0133] Comparing Examples 1 to 4 with Comparative Examples 1 to 2, when the first intermediate recrystallization annealing heating temperature is not within the range of 510 to 540°C, the second intermediate recrystallization annealing heating temperature is not within the range of 460 to 480°C, the first air cushion continuous annealing furnace annealing temperature is not within the range of 490 to 520°C, the second air cushion continuous annealing furnace annealing temperature is not within the range of 490 to 510°C, and the third air cushion continuous annealing furnace annealing temperature is not within the range of 440 to 460°C, the elongation, deflection height, grain size and standard deviation of the tin-phosphorus bronze strip for etching prepared therefrom cannot meet the requirements of the tin-phosphorus bronze strip for etching. When the annealing heating temperature is too low, the purpose of recrystallization annealing cannot be achieved, so that the strength of the strip is too high, the internal stress is too large, and the organization cannot achieve the purpose of fineness; when the annealing temperature is too high, the grain structure is too coarse and the strength is too low, and the purpose of etching cannot be achieved.

[0134] Comparing Example 1 with Comparative Examples 3 to 5, when the rolling passes of cold rolling blanking change, the tin-phosphor bronze strip for etching will have excessive deformation in each pass, resulting in surface cracks on the strip, affecting the performance of the strip, and will also affect the surface quality of the strip, thereby affecting the etching performance; when the rolling passes of intermediate rolling deformation change, the tin-phosphor bronze strip for etching will have excessive deformation in a single pass, resulting in fine cracks on the surface of the strip, affecting the yield and surface quality of the strip, and too small deformation in a single pass will lead to too many processing passes, which will also affect the production cost; when the rolling passes of finish rolling deformation change, the tin-phosphor bronze strip for etching will cause excessive deformation in a single pass, affecting the surface quality and processing accuracy of the strip, thereby affecting the mechanical properties of the strip.

[0135] Comparing Example 1 with Comparative Examples 6 to 10, when the annealing temperature and time of the first air cushion continuous annealing furnace annealing, the annealing temperature and time of the second air cushion continuous annealing furnace annealing, and the annealing temperature and time of the third air cushion continuous annealing furnace annealing in the present application are not adopted respectively, the performance indicators, warping height and grain size of the tin-phosphorus bronze strip for etching will change, and the purpose of the tin-phosphorus bronze strip for etching cannot be achieved; when the annealing temperature and time of any two of the annealing temperatures and time of the first air cushion continuous annealing furnace annealing, the annealing temperature and time of the second air cushion continuous annealing furnace annealing, and the annealing temperature and time of the third air cushion continuous annealing furnace annealing are not within the range, the tin-phosphorus bronze strip for etching will not be able to obtain a tin-phosphorus bronze strip whose mechanical properties, grain size and deflection height meet the requirements at the same time because the annealing processes cannot be coordinated and controlled.

[0136] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a tin-phosphor bronze strip for etching, characterized in that: The preparation method comprises the following steps: Step S1: homogenizing and annealing the ingot and performing double-sided milling to obtain an initial ingot; Step S2: cold rolling the initial blank for 8 passes to obtain a 2.5 mm cold rolled blank, and then performing thick strip washing after the first intermediate recrystallization annealing to obtain a cold rolled blank; Step S3: performing intermediate rolling deformation on the cold rolled blank, the intermediate rolling deformation passes are 3 passes, and an intermediate blank of 1.0 mm is obtained. After the second intermediate recrystallization annealing, thick strip washing is performed to obtain an intermediate blank; Step S4: performing finish rolling deformation on the intermediate billet, the number of finish rolling deformation passes is 3, a finish rolling billet amount of 0.4 mm is obtained, and the first air cushion continuous annealing is performed to obtain a finish rolling billet; Step S5: performing bottom rolling on the finished rolled billet, the bottom rolling passes are 2, and performing a second air cushion continuous annealing to obtain a bottom rolled billet; Step S6: rolling the bottom blank into finished product, with one rolling pass, and performing a third air cushion continuous annealing to obtain a finished product; Step S7: the finished material is divided into strips, rolled up and stored to obtain tin-phosphor bronze strips for etching.

2. The preparation method according to claim 1, characterized in that In the step S1, the ingot is prepared by horizontal continuous casting of tin-phosphor bronze raw material; The tin-phosphor bronze raw material has a tin content of 5.7-6.7% and a phosphorus content of 0.1-0.25%; The thickness of the ingot is 14-15 mm.

3. The preparation method according to claim 1, characterized in that: In step S2, the rolling process of 8 passes is 14.5-12-9.8-7.9-6.3-4.8-3.7-2.9-2.5 mm; The heating temperature of the first intermediate recrystallization annealing is 510-540° C., and the holding time is 5-7 hours.

4. The preparation method according to claim 1, characterized in that: In step S3, the rolling process of three passes is 2.5-1.7-1.3-1.0 mm; The heating temperature of the second intermediate recrystallization annealing is 460-480° C., and the holding time is 5-7 hours.

5. The preparation method according to claim 1, characterized in that: In step S4, the rolling process of three passes is 1.0-0.7-0.5-0.4 mm; The temperature of the first air cushion continuous annealing is 490-520° C., and the holding time is 20-40 seconds.

6. The preparation method according to claim 1, characterized in that: In step S5, the rolling process of 2 passes is 0.4-0.32-0.27 mm; The temperature of the second air cushion continuous annealing is 490-510° C., and the holding time is 20-40 seconds.

7. The preparation method according to claim 1, characterized in that: In the step S6, the rolling deformation in one pass is 5 to 10%.

8. The preparation method according to claim 1, characterized in that: In the step S6, the temperature of the third air cushion continuous annealing is 440-460° C., and the holding time is 50-80 seconds.

9. The preparation method according to claim 1, characterized in that: In the step S7, the blade gap of the vacuum roller slitting shearing machine used for slitting is 40-60% of the thickness of the finished material.

10. The tin-phosphor bronze strip for etching prepared by the preparation method according to any one of claims 1 to 9, characterized in that: The tin-phosphor bronze strip for etching has a tensile strength of 600-625 MPa, a yield strength of 550-585 MPa, a Vickers hardness of 195-210 HV, an elongation of 25-30%, a deflection height of 1-2 mm, a grain size of 1-3 μm, and a standard deviation of 0.56-1.26.

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