Preparation method of wide molybdenum strip

Abstract

The invention discloses a preparation method of a wide molybdenum strip. The preparation method comprises the specific steps of material preparation, riveting, rough rolling, welding, finish rolling and vacuum heat treatment. According to the preparation method of the wide molybdenum strip, the nickel strip or the nickel-plated steel strip is adopted as the leading strip, the nickel strip or the nickel-plated steel strip is connected with the molybdenum strip through riveting and spot welding processes in different process steps, the overall matching degree is high, large-tension rolling can be conducted when the molybdenum strip is machined, therefore, machining of the wide molybdenum strip is met, the production efficiency is greatly improved, and the production cost is reduced. The product quality and the product utilization rate are improved.

Description

Technical Field

[0001] The invention relates to the technical field of molybdenum material processing, and in particular to a method for preparing a wide-width molybdenum strip. Background Art

[0002] Molybdenum strip has unique properties such as high melting point, good thermal conductivity, low thermal expansion and good electrical conductivity. These properties make molybdenum strip widely used in different industries, such as high-temperature heating elements, strip heaters, electrical contacts, filament supports, cathode fluorescent tubes CCFL for display and test equipment structures in special fields. The performance requirements for the required molybdenum strip are often much higher than those in ordinary applications, especially the application of molybdenum strips with a thickness of less than 0.10mm is increasing. At present, most of the molybdenum narrow strips on the market are less than 5mm for electric light sources. This kind of molybdenum strip is usually made of molybdenum wire as a blank, rolled into a flat shape on a small roller mill with a width of less than 100mm, and then further rolled into narrow molybdenum strips, or rolled into strips with narrow molybdenum bars. This rolling process is relatively easy, and the strip size accuracy and plate shape are also easy to control. However, the preparation of wider molybdenum foil strips is limited by equipment and processes, as well as the difficulty of welding and brittle fracture of molybdenum materials. Few molybdenum strips with a width of more than 100mm are produced. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for preparing a wide-width molybdenum strip, thereby solving the problem of the difficulty in processing the wide-width molybdenum strip and ensuring product quality.

[0004] The technical solution adopted by the present invention is: A method for preparing a wide molybdenum strip, the specific steps are: S1. Material preparation: Use cold-rolled annealed molybdenum strip with a thickness of 0.8-1.0mm, a width of finished product width + 15-25mm, and a length of ≥2000mm; S2, riveting: riveting the lead strips at both ends of the molybdenum strip in the length direction to form a composite strip; S3, rough rolling: the composite strip in S2 is passed through a rough rolling mill, and the guide strips at both ends are fixed on a coiler to perform rough rolling on the composite strip to produce a molybdenum strip A; S4, welding: spot welding the two ends of the molybdenum strip A to connect the lead strip 2 to form a composite strip 2; S5, finishing rolling: the composite strip 2 is passed through the finishing mill, the guide strips 2 at both ends are fixed on the coiler respectively, and the finishing mill works to roll the composite strip to the finished product thickness to obtain the molybdenum strip B; S6. Vacuum heat treatment: The molybdenum strip B is subjected to vacuum annealing in a vacuum furnace to obtain a finished molybdenum strip.

[0005] Specifically, in the claimed S1, the recrystallized structure of the molybdenum strip accounts for ≤15%.

[0006] Specifically, the first and second leader strips are both nickel strips or nickel-plated steel strips, with a thickness of ±0.2-0.5 mm of the thickness of the connected strips, a width consistent with the width of the connected strips, and a length of ≥2000 mm.

[0007] Specifically, when the rough rolling deformation in S3 is 45% to 65%, stress relief annealing treatment is performed, and the total rough rolling deformation is 50% to 85%.

[0008] Specifically, before welding, the molybdenum strip A is cut cleanly and subjected to stress relief annealing on a slitting machine.

[0009] Specifically, when the S5 finishing deformation is 40% to 60%, stress relief annealing is performed, and the total finishing deformation is 25% to 75%.

[0010] Specifically, the S3 and S5 rolling are both carried out on a four-roller reversible rolling mill, and the rolling tension voltage load is 1.5-11V.

[0011] Specifically, in the S4, the welding current is controlled at 20-30A, and the electrode rod is made of copper alloy.

[0012] Specifically, the vacuum annealing temperature in S6 is 750°C to 850°C.

[0013] Due to the adoption of the above-mentioned technical solution, the present invention has the following advantages: The method for preparing wide molybdenum strip of the present invention adopts nickel strip or nickel-plated steel strip as the guide strip, and adopts riveting and spot welding processes to connect with the molybdenum strip in different process steps, has high overall matching degree, can carry out high tension rolling during molybdenum strip processing, thereby meeting the processing of wide molybdenum strip, greatly improving production efficiency, and enhancing product quality and product utilization. DETAILED DESCRIPTION

[0014] The present invention will be further explained below in conjunction with the embodiments, which are not intended to limit the protection scope of the present invention. The purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention.

[0015] A method for preparing a wide molybdenum strip of the present invention comprises the following specific steps: S1. Material preparation: Use cold-rolled annealed molybdenum strip with a thickness of 0.95mm, a width of 160mm, and a length of ≥2200mm. The microstructure of the molybdenum strip after return is a banded structure that overlaps each other, and the proportion of the formed recrystallized structure is ≤15%.

[0016] S2. Riveting: Lead strips are riveted at both ends of the molybdenum strip in the length direction to form a composite strip; the lead strip is a nickel strip with a thickness of 0.7 mm, a width of 160 mm, and a length of 2000 mm.

[0017] S3, rough rolling: the composite strip in S2 is passed through a four-roll reversible rolling mill, and the guide strips at both ends are fixed on the coiler to perform rough rolling on the composite strip. The initial tension voltage load is 10.5V. As the thickness decreases, the tension voltage load also decreases accordingly. When the deformation is 55%, stress relief annealing is performed. The total deformation of rough rolling is 82%. After rough rolling, the edges are trimmed and stress relief annealing is performed to obtain molybdenum strip A.

[0018] S4, welding: spot welding is performed on both ends of the molybdenum strip A to connect the lead strip 2 to form a composite strip 2. The lead strip 2 uses a nickel strip with a thickness of 0.4 mm and the same width as the molybdenum strip A. Copper alloy electrode rods are used for spot welding, and the welding current is 26A.

[0019] S5, finishing rolling: the composite strip 2 is passed through a four-roll reversible rolling mill, and the lead strips 2 at both ends are fixed on the coiler respectively. The initial tension voltage load is 5.5V. As the thickness decreases, the tension voltage load also decreases accordingly. When the deformation is 45%, stress relief annealing is performed. The total deformation of finishing rolling is 75%. The composite strip is rolled to a molybdenum strip B with a thickness of 0.05mm, a width of 137mm, and a length of more than 35.

[0020] S6. Vacuum heat treatment: The molybdenum strip B is subjected to vacuum annealing treatment in a vacuum furnace at 800° C. to obtain a finished molybdenum strip.

[0021] The parts not described in detail in this invention are prior art.

[0022] The embodiments selected herein for the purpose of disclosing the invention are currently considered to be suitable, but it should be understood that the invention is intended to include all changes and modifications of the embodiments that fall within the scope of the concept and invention.

Claims

1. A method for preparing a wide molybdenum strip, characterized in that: The specific steps are: S1. Material preparation: Use cold-rolled annealed molybdenum strip with a thickness of 0.8-1.0mm, a width of finished product width + 15-25mm, and a length of ≥2000mm; S2, riveting: riveting the lead strips at both ends of the molybdenum strip in the length direction to form a composite strip; S3, rough rolling: the composite strip in S2 is passed through a rough rolling mill, and the guide strips at both ends are fixed on a coiler to perform rough rolling on the composite strip to produce a molybdenum strip A; S4, welding: spot welding the two ends of the molybdenum strip A to connect the lead strip 2 to form a composite strip 2; S5, finishing rolling: the composite strip 2 is passed through the finishing mill, the guide strips 2 at both ends are fixed on the coiler respectively, and the finishing mill works to roll the composite strip to the finished product thickness to obtain the molybdenum strip B; S6. Vacuum heat treatment: The molybdenum strip B is subjected to vacuum annealing in a vacuum furnace to obtain a finished molybdenum strip.

2. The method for preparing a disk-width molybdenum strip according to claim 1, characterized in that: In the above-mentioned S1, the recrystallized structure of the molybdenum strip accounts for ≤15%.

3. The method for preparing a wide molybdenum strip according to claim 1, characterized in that: The first and second leader strips are both nickel strips or nickel-plated steel strips, with a thickness of ±0.2-0.5mm of the thickness of the connected strips, a width consistent with the width of the connected strips, and a length of ≥2000mm.

4. The method for preparing a wide molybdenum strip according to claim 1, characterized in that: When the rough rolling deformation in S3 is 45% to 65%, stress relief annealing is performed, and the total rough rolling deformation is 50% to 85%.

5. The method for preparing a wide molybdenum strip according to claim 1, characterized in that: Before the S4 welding operation, the molybdenum strip A is cut cleanly at its edges and subjected to stress relief annealing on a slitting machine.

6. The method for preparing a wide molybdenum strip according to claim 1, characterized in that: When the S5 finishing deformation is 40% to 60%, the stress relief annealing treatment is performed, and the total finishing deformation is 25% to 75%.

7. The method for preparing a wide molybdenum strip according to claim 1, characterized in that: The S3 and S5 rolling are both carried out on a four-roller reversible rolling mill, and the rolling tension voltage load is 1.5-11V.

8. The method for preparing a wide molybdenum strip according to claim 1, characterized in that: In the S4, the welding current is controlled at 20-30A, and the electrode rod is made of copper alloy.

9. The method for preparing a wide molybdenum strip according to claim 1, characterized in that: The vacuum annealing temperature in S6 is 750°C to 850°C.