Rolling method for cold continuous rolling of titanium and titanium alloy wires

Abstract

The invention belongs to the technical field of titanium alloy wire machining, and particularly relates to a rolling method for cold continuous rolling of titanium and titanium alloy wires. The ten-square hole pattern is designed to be used for reducing forming of titanium and titanium alloy wires, and the hole pattern is insensitive to roller abrasion and suitable for large-scale continuous rolling; compared with a hexagonal or octagonal hole pattern, folding is not generated in the rounding process, and the forming process is easy to control; and small deformation is designed for the hole pattern for rounding, so that metal flow after rolling is controlled, and the dimensional accuracy of the titanium and titanium alloy wires is guaranteed. A ten-square hole pattern for reducing and a round hole pattern for rounding are designed, hole pattern series rollers are manufactured according to the ten-square hole pattern and the round hole pattern, the hole pattern series rollers are further horizontally and vertically arranged in a cold continuous rolling mill, and high-precision titanium and titanium alloy wires are obtained through high-speed continuous rolling. The cold tandem rolling mill used in the rolling method is compact, the occupied area of a workshop is small, and the rolling method has remarkable cost and efficiency advantages in the aspect of high-speed rolling forming of cold-machined titanium and titanium alloy wires.

Description

Technical Field

[0001] The invention belongs to the technical field of titanium alloy wire processing, and particularly relates to a rolling method for cold tandem rolling of titanium and titanium alloy wires. Background Art

[0002] With the development of titanium alloy wire forming technology, wire forming technology with high efficiency, high surface quality and high precision requirements has become the development direction. Existing wire rolling usually adopts fixed die cold drawing or roll die cold drawing, and further combines intermediate vacuum or atmospheric annealing to prepare wires such as pure titanium, TB9, TB14, Ti15Mo, TC16, etc.; among them, fixed die cold drawing requires lubricant, and roll die cold drawing usually adopts an elliptical-round pass, and multiple cold drawing machines or continuous drawing machines are required for high-efficiency production, and it is difficult to stably control the dimensional deviation of the finished wire within 0.02 mm by using the above technologies. Therefore, the invention adopts a cold tandem rolling mill with a compact structure, and through innovative design of the pass and reduction ratio for tandem rolling, it is applicable to the high-efficiency rolling forming of titanium and titanium alloy wires. Summary of the Invention

[0003] The purpose of the invention is to overcome the above-mentioned disadvantages of the prior art and provide a rolling method for cold tandem rolling of titanium and titanium alloy wires.

[0004] To achieve the above purpose, the invention provides the following technical solutions: The invention provides a rolling method for cold tandem rolling of titanium and titanium alloy wires, including the following steps; Step 1, pass design: design a series of passes for reducing the diameter of titanium and titanium alloy wires to be processed in cold tandem rolling and a series of sizing passes (sizing pass series for finished products); the passes in the series of passes for reducing the diameter are all ten-sided passes, the reduction ratio per pass for diameter reduction is 11% - 17.5%, the central angle β corresponding to each face of the ten-sided pass is 36°, and the radius γ of the chamfer at the bottom of the groove of the ten-sided pass is 0.8 mm - 1.2 mm; the chamfer R of the ten-sided pass is (1 / 4 - 1 / 3)d0, where d0 is the diameter of the circle of the cross-sectional area of the ten-sided wire; the series of sizing passes adopts round passes with gradually increasing precision and gradually decreasing reduction ratio, the expansion angle of the round pass is 15° - 25°, and the reduction ratio per pass for sizing is 2% - 8%.

[0005] Step 2, roll manufacturing: Use an optical profile grinder to separately manufacture the pass series for diameter reduction and the pass series for sizing on different rolls, obtaining the roll for the pass series for diameter reduction and the roll for the pass series for sizing; the material of the roll is cold work die steel such as Cr12MoV, SKD11, DC53, etc., and the HRC hardness ≥ 63; the magnification of the optical path system of the optical profile grinder is 50 times. When grinding the roll, the material of the grinding wheel is selected from one of white corundum, brown corundum or diamond to ensure that the deviation between the grinding reference and the pass center line is less than 0.001 mm, and the grinding accuracy is less than 0.003 mm.

[0006] Step 3, tandem cold rolling: First, install the roll for the pass series for diameter reduction and the roll for the pass series for sizing on the tandem cold rolling mill respectively, and adopt a horizontal-vertical arrangement. Then, subject the titanium and titanium alloy wire materials to be processed to tandem cold rolling successively using the roll for the pass series for diameter reduction and the roll for the pass series for sizing. According to the cold working properties of different titanium and titanium alloys, some materials also need to be matched with vacuum annealing or atmosphere protection in-line annealing. During the tandem cold rolling process, the roll for the pass series for diameter reduction and the roll for the pass series for sizing are immersed in the rolling oil. The tandem cold rolling speed is 10 m / min to 100 m / min, and the required titanium and titanium alloy wire materials are finally obtained.

[0007] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects: The present invention designs a ten-sided pass for the diameter reduction forming of titanium and titanium alloy wire materials. Compared with the twelve-sided pass, this pass is not sensitive to roll wear and is suitable for mass tandem rolling; compared with the six-sided or eight-sided pass, no folding occurs during the sizing process, and the forming process is easy to control; further, by designing a smaller deformation amount for the pass for sizing to control the metal flow after rolling, the dimensional accuracy of the titanium and titanium alloy wire materials is ensured. The present invention designs a ten-sided pass for diameter reduction and a round pass for sizing, manufactures the roll for the pass series based on this, adopts a tandem cold rolling mill with a compact structure, further arranges the roll for the pass series horizontally-vertically in the tandem cold rolling mill, and obtains high-precision titanium and titanium alloy wire materials through high-speed tandem rolling. Compared with the traditional wire drawing process, the rolling method of this wire material greatly improves the processing efficiency of titanium and titanium alloy wire materials, and can ensure that the out-of-roundness of the wire material is within 0.02 mm under the condition of high-speed rolling. The tandem cold rolling mill used in the rolling method of the present invention has a compact equipment and occupies less workshop area, and has significant cost and efficiency advantages in the high-speed rolling forming of cold-worked titanium and titanium alloy wire materials. Description of the Drawings

[0008] The drawings here are incorporated into the specification and form a part of this specification, and are used together with the specification to explain the principle of the present invention.

[0009] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0010] Figure 1 It is a flowchart of the rolling method of the present invention; Figure 2 It is a ten-square pass pattern for cold tandem rolling and diameter reduction of the present invention; Figure 3 It is a pass pattern for cold tandem rolling and sizing of the present invention. Detailed implementation manners

[0011] Here, the exemplary embodiments will be described in detail, and the examples are shown in the drawings. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with the present invention. On the contrary, they are only examples consistent with some aspects of the present invention detailed in the appended claims.

[0012] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the drawings and embodiments.

[0013] The present invention provides a rolling method for cold tandem rolling of titanium and titanium alloy wire rods. Refer to Figures 1-3 as shown, including the following steps; Step 1, pass design: Design a series of passes for cold tandem rolling and diameter reduction of the titanium and titanium alloy wire rods to be processed, as well as a series of passes for sizing (finished sizing pass series); the passes in the diameter reduction pass series are all ten-square passes, the reduction pass deformation is 11% - 17.5%, the central angle β corresponding to each face of the ten-square pass is 36°, and the fillet radius γ at the bottom of the groove of the ten-square pass is 0.8 mm - 1.2 mm; the chamfer R of the ten-square pass is (1 / 4 - 1 / 3)d0, where d0 is the diameter of the circle of the cross-sectional area of the ten-square wire rod; the sizing pass series adopts round passes with gradually increasing precision and gradually decreasing deformation, the expansion angle of the round pass is 15° - 25°, and the sizing pass deformation is 2% - 8%.

[0014] Step 2, roll manufacturing: Use an optical profile grinder to manufacture the pass series for diameter reduction and the pass series for sizing on different rolls respectively, obtaining the roll for the pass series for diameter reduction and the roll for the pass series for sizing; the material of the roll is cold work die steel such as Cr12MoV, SKD11, DC53, etc., and the HRC hardness ≥ 63; the magnification of the optical path system of the optical profile grinder is 50 times. When grinding the roll, the material of the grinding wheel is selected from one of white corundum, brown corundum or diamond to ensure that the deviation between the grinding reference and the pass center line is less than 0.001 mm, and the grinding accuracy is less than 0.003 mm.

[0015] Step 3, tandem cold rolling: First, install the roll for the pass series for diameter reduction and the roll for the pass series for sizing on the tandem cold rolling mill respectively, and adopt a horizontal-vertical arrangement. Then, subject the titanium and titanium alloy wire materials to be processed to tandem cold rolling successively using the roll for the pass series for diameter reduction and the roll for the pass series for sizing. According to the cold working properties of different titanium and titanium alloys, some materials also need to be matched with vacuum annealing or atmosphere protection online annealing. During the tandem cold rolling process, the roll for the pass series for diameter reduction and the roll for the pass series for sizing are immersed in the rolling oil. The tandem cold rolling speed is 10 m / min to 100 m / min, and finally the required titanium and titanium alloy wire materials are obtained.

[0016] To prove the effect of the present invention, the following examples are provided for verification. Example 1

[0017] This example provides a rolling method for tandem cold rolling of titanium and titanium alloy wire materials. Refer to Figures 1-3 as shown, to prepare pure titanium - Φ5.0 mm wire materials, the specific steps are as follows: Step 1, pass design: The pass series for diameter reduction in the tandem cold rolling of pure titanium are all ten-sided passes. The reduction ratio of each pass is 17.5%. The central angle β corresponding to each face of the ten-sided pass is 36°. The radius γ of the chamfer at the bottom of the groove is 0.8 mm to 1.2 mm. The pass filling degree is 92%. The height H of the pass depends on the reduction ratio of each pass, the roll gap of the rolling mill and the material springback. The chamfer R is (1 / 4 - 1 / 3)d0, where d0 is the diameter of the circle of the cross-sectional area of the ten-sided wire material; the reduction ratio of each tandem cold rolling mill stand after rolling is 17.5%. The pass series for sizing are round passes with gradually increasing roundness and dimensional deviation accuracy, and the accuracy is gradually improved and the reduction ratio is gradually decreased. The expansion angle of the round pass is 25°, and the sizing is designed for 3 passes, and the reduction ratios of each pass are 8.0%, 6.5%, and 4.0% respectively.

[0018] Step 2, roll manufacturing: After designing the pass, use an optical profile grinder to manufacture the pass series for diameter reduction and the pass series for sizing on different rolls respectively, obtaining the rolls with the pass series for diameter reduction and the rolls with the pass series for sizing for cold continuous rolling of pure titanium wire; the material of the roll is Cr12MoV cold work die steel, and the HRC hardness ≥ 63; the magnification of the optical path system of the optical profile grinder is 50 times, and white corundum grinding wheels are used during grinding to ensure that the deviation between the grinding reference and the pass center line is less than 0.001 mm, and the grinding accuracy is less than 0.003 mm.

[0019] Step 3, cold continuous rolling: First, install the rolls with the pass series for diameter reduction and the rolls with the pass series for sizing on 8 cold continuous rolling mills respectively, and arrange them in a flat-vertical manner. Then, first use the rolls with the pass series for diameter reduction and then use the rolls with the pass series for sizing for cold continuous rolling of Φ8.9 mm pure titanium wire. During cold continuous rolling, the rolls with the pass series for diameter reduction and the rolls with the pass series for sizing are immersed in rolling oil, and the cold continuous rolling speed is 50 m / min - 100 m / min; the circles with equal cross-sectional areas of the pure titanium wire corresponding to each cold continuous rolling mill after rolling are Φ8.08 mm, Φ7.34 mm, Φ6.67 mm, Φ6.06 mm, Φ5.50 mm, Φ5.28 mm, Φ5.10 mm, Φ5.0 mm in sequence, and finally, Φ5.0 mm pure titanium wire is prepared. Example 2

[0020] This example provides a rolling method for cold continuous rolling of titanium and titanium alloy wire. As shown in Figures 1-3 the figure, to prepare TB14-Φ4.0 mm wire, the specific steps are as follows: Step 1, pass design: The pass series for diameter reduction in cold continuous rolling of TB14 titanium alloy are all ten-sided passes. The reduction ratio per pass is 13.5%. The central angle β corresponding to each face of the ten-sided pass is 36°, the radius of the chamfer at the bottom of the groove γ is 0.8 mm - 1.2 mm, the pass filling degree is 94%, the pass height H depends on the reduction ratio per pass, the roll gap of the rolling mill, and the material springback. The chamfer R is (1 / 4 - 1 / 3)d0, where d0 is the diameter of the circle with the cross-sectional area of the ten-sided wire; the reduction ratio of each cold continuous rolling mill frame after rolling is 13.5%. The pass series for sizing are round passes with gradually improved roundness and dimensional deviation accuracy, and the accuracy is gradually improved and the reduction ratio is gradually reduced. The expansion angle of the round pass is 20°, and the sizing is designed for 3 passes, and the reduction ratios per pass are 7.0%, 5.5%, and 2.0% respectively.

[0021] Step 2: Roll manufacturing: After designing the pass, use an optical profile grinder to manufacture the pass series for diameter reduction and the pass series for sizing on different rolls respectively, obtaining the rolls with the pass series for diameter reduction and the rolls with the pass series for sizing for cold continuous rolling of TB14 titanium alloy wire; the material of the rolls is SKD11 cold work die steel, and the HRC hardness ≥ 63; the magnification of the optical path system of the optical profile grinder is 50 times, and a brown fused alumina grinding wheel is used during grinding to ensure that the deviation between the grinding reference and the pass center line is less than 0.001 mm, and the grinding accuracy is less than 0.003 mm.

[0022] Step 3: Cold continuous rolling: First, install the rolls with the pass series for diameter reduction and the rolls with the pass series for sizing on 13 cold continuous rolling mills respectively, and arrange them in a flat-vertical manner. Then, use the rolls with the pass series for diameter reduction first and then the rolls with the pass series for sizing to conduct cold continuous rolling on the Φ8.9 mm TB14 titanium alloy wire. During cold continuous rolling, the rolls with the pass series for diameter reduction and the rolls with the pass series for sizing are immersed in rolling oil, and the cold continuous rolling speed is 40 - 80 m / min; the circles with equal cross-sectional areas of the TB14 titanium alloy wire corresponding to each cold continuous rolling mill after rolling are Φ8.28 mm, Φ7.70 mm, Φ7.16 mm, Φ6.66 mm, Φ6.19 mm, Φ5.76 mm, Φ5.36 mm, Φ4.98 mm, Φ4.63 mm, Φ4.31 mm, Φ4.16 mm, Φ4.04 mm, Φ4.0 mm in sequence, and finally, the Φ4.0 mm TB14 titanium alloy wire is prepared. Example 3

[0023] This example provides a rolling method for cold continuous rolling of titanium and titanium alloy wire. As shown in Figures 1-3 the figure, to prepare TC16 - Φ3.0 mm wire, the specific steps are as follows: Step 1: Pass design: The pass series for diameter reduction in cold continuous rolling of TC16 titanium alloy are all ten-sided passes. The reduction ratio per pass is 11%. The central angle β corresponding to each face of the ten-sided pass is 36°, the radius of the chamfer at the bottom of the groove γ is 0.8 mm - 1.2 mm, the pass filling degree is 94%, the height H of the pass depends on the reduction ratio per pass, the roll gap of the rolling mill, and the material springback rate. The chamfer R is (1 / 4 - 1 / 3)d0, where d0 is the diameter of the circle with the cross-sectional area of the ten-sided wire; the reduction ratio of each cold continuous rolling mill stand after rolling is 11%. The pass series for sizing are round passes with gradually increasing roundness and dimensional deviation accuracy, and the accuracy gradually increases and the reduction ratio gradually decreases. The expansion angle of the round pass is 15°, and the sizing is designed for 3 passes, and the reduction ratios per pass are 8.0%, 7.0%, and 3.5% respectively.

[0024] Step 2, roll manufacturing: After designing the pass, use an optical profile grinder to manufacture the pass series for diameter reduction and the pass series for sizing on different rolls respectively, obtaining the rolls of the pass series for diameter reduction and the rolls of the pass series for sizing for cold continuous rolling of TC16 titanium alloy wire; the material of the roll is DC53 cold work die steel, and the HRC hardness ≥ 63; the magnification of the optical path system of the optical profile grinder is 50 times, and a diamond grinding wheel is used during grinding to ensure that the deviation between the grinding reference and the pass center line is less than 0.001 mm, and the grinding accuracy is less than 0.003 mm.

[0025] Step 3, cold continuous rolling and intermediate annealing: First, install the rolls of the pass series for diameter reduction and the rolls of the pass series for sizing on 20 cold continuous rolling mills respectively, and arrange them in a flat-vertical manner. Then, use the rolls of the pass series for diameter reduction first and then the rolls of the pass series for sizing to cold continuously roll the Φ8.9 mm TC16 titanium alloy wire. During cold continuous rolling, the rolls of the pass series for diameter reduction and the rolls of the pass series for sizing are immersed in rolling oil, and the cold continuous rolling speed is 10 m / min - 50 m / min; the circles with equal cross-sectional areas of the TC16 titanium alloy wire corresponding to each cold continuous rolling mill after rolling are Φ8.40 mm, Φ7.92 mm, Φ7.47 mm, Φ7.05 mm, Φ6.65 mm, Φ6.27 mm, Φ5.92 mm, Φ5.58 mm, Φ5.27 mm, Φ4.97 mm, Φ4.69 mm, Φ4.42 mm, Φ4.17 mm, Φ3.94 mm, Φ3.71 mm, Φ3.50 mm, Φ3.31 mm, Φ3.17 mm, Φ3.06 mm, Φ3.0 mm in sequence. According to the cold working performance of TC16 titanium alloy, when the cumulative deformation amount reaches between 55% and 70% during the first cold continuous rolling, intermediate vacuum annealing or argon protection annealing is required, the annealing temperature is 650 °C - 750 °C, and after cooling, continue cold continuous rolling to finally prepare the Φ3.0 mm TC16 titanium alloy wire.

[0026] To further verify the effectiveness of the technical solution provided by the present invention, use a digital micrometer to measure the dimensions of the head, 1 / 4 position, middle, 3 / 4 position, tail and other parts of the pure titanium wire, TB14 titanium alloy wire, and TC16 titanium alloy wire prepared in the above embodiments with a weight of 50 kg - 100 kg. The maximum and minimum point dimensions are obtained by measuring each part multiple times, and the results are shown in Table 1: Table 1

[0027] In summary, as can be seen from Table 1, the grooved rolls for reducing diameter and the grooved rolls for sizing made by using the grooved roll series for cold tandem rolling reduction of diameter and the grooved roll series for sizing of the present invention can ensure that the out-of-roundness of the titanium and titanium alloy wire rods prepared under the high-speed rolling state is within 0.02 mm, and can meet the high-efficiency and high-precision forming requirements of the titanium and titanium alloy wire rods.

[0028] It should also be noted that the cross-sectional area of the wire rod can be calculated by using the groove width, the groove height H, the groove filling degree, and the reduction ratio.

[0029] The above are only specific embodiments of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention.

[0030] It should be understood that the present invention is not limited to the above-described content and can be modified and changed without departing from its scope. The scope of the present invention is only limited by the appended claims.

Claims

1. A rolling method for cold tandem rolling of titanium and titanium alloy wire rods, characterized in that, It includes the following steps; Step 1, pass design: Design the pass series for cold tandem rolling and reducing the diameter of the titanium and titanium alloy wire to be processed, as well as the pass series for sizing, and design the reduction amount per pass respectively; Step 2, roll manufacturing: Manufacture the pass series for reducing the diameter and the pass series for sizing on different rolls respectively to obtain the roll for the pass series for reducing the diameter and the roll for the pass series for sizing; Step 3, cold tandem rolling: First, install the roll for the pass series for reducing the diameter and the roll for the pass series for sizing on the cold tandem rolling mill respectively, and then cold tandem roll the titanium and titanium alloy wire to be processed successively with the roll for the pass series for reducing the diameter and the roll for the pass series for sizing, and finally obtain the required titanium and titanium alloy wire; 2. The rolling method according to claim 1, characterized in that, In Step 1, the pass shapes of the pass series for reducing the diameter are all the same; 3. The rolling method according to claim 1, characterized in that, In Step 1, the passes of the pass series for reducing the diameter are all ten-sided passes, and the reduction amount per pass for reducing the diameter is 11% - 17.5%; 4. The rolling method according to claim 3, characterized in that The central angle β corresponding to each face of the ten-sided pass is 36°; 5. The rolling method according to claim 3, wherein The chamfer radius γ at the bottom of the groove of the ten-sided pass is 0.8 mm - 1.2 mm; 6. The rolling method according to claim 3, wherein The chamfer R of the ten-sided pass is (1 / 4 - 1 / 3)d0, where d0 is the diameter of the circle of the cross-sectional area of the ten-sided wire; 7. The rolling method according to claim 1, characterized in that In Step 1, the passes of the pass series for sizing are all round passes, the expansion angle of the round pass is 15° - 25°, and the reduction amount per pass for sizing is 2% - 8%; 8. The rolling method according to claim 1, characterized in that, In Step 2, the material of the roll is one of Cr12MoV, SKD11, and DC53, and the HRC hardness ≥ 63; 9. The rolling method according to claim 1, characterized in that, In Step 2, use an optical profile grinder to manufacture the roll for the pass series for reducing the diameter and the roll for the pass series for sizing respectively. The magnification of the optical path system of the optical profile grinder is 50 times, and the grinding accuracy is less than 0.003 mm; 10. The rolling method according to claim 1, characterized in that, In Step 3, the roll for the pass series for reducing the diameter and the roll for the pass series for sizing installed on the cold tandem rolling mill are both arranged in a horizontal-vertical layout. During the cold tandem rolling process, the roll for the pass series for reducing the diameter and the roll for the pass series for sizing are both immersed in the rolling oil, and the cold tandem rolling speed is 10 m / min - 100 m / min.

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