A device for improving the coil shape of titanium strip and annealing method thereof

Abstract

The present invention provides a device for improving the roll shape of a titanium strip and an annealing method thereof. The device comprises a box furnace, a base with a load-bearing shaft respectively arranged on both sides of the box furnace, and a heating element distributed on the inner wall of the box furnace; the load-bearing shaft passes through the side wall and is arranged inside the box furnace, and the load-bearing shaft comprises an inner shaft and a cooling system arranged on the outer wall of the inner shaft, and a shrinkage diameter is also arranged outside the load-bearing shaft; during operation, the titanium strip is rolled, vacuumed, heated, and rotated, and heated and kept warm according to certain requirements, and cooled with the furnace, so that a titanium strip with a good roll shape is obtained. The titanium strip obtained by the present invention has a good roll shape, and the unevenness after annealing and natural expansion is ≤1.2%. The titanium strip can be used directly by cutting it into plates, without the need for subsequent press correction, plate stress relief annealing and other processes, and the economic benefits are excellent.

Description

Technical Field

[0001] The invention relates to a device for improving the coil shape of a titanium strip and an annealing method thereof, belonging to the technical field of titanium strip annealing process. Background Art

[0002] When traditional titanium coils are annealed in upright hood annealing furnaces, due to the increasing weight of single coils, the increasing width of coils, and the pursuit of efficiency in double or multi-coil stacking, the coils are prone to bend in the middle under the effect of their own weight. During the heating process, the entire coil is prone to "drumming" - high in the middle and low on both sides. After the entire coil is opened, periodic wave shapes and "C-shaped" coil problems will appear. Summary of the invention

[0003] In order to solve the above problems, the present invention provides a device for improving the coil shape of titanium strip and an annealing method thereof, which can effectively avoid coil shape problems such as warping, "drumming", wavy shape and "C-warping" during the annealing process of the titanium strip.

[0004] The present invention is achieved through the following technical method: a device for improving the coil shape of a titanium strip, comprising a box furnace, a base with a load-bearing shaft respectively arranged on both outer sides of the box furnace, and a heating element distributed on the inner wall of the box furnace; the load-bearing shaft passes through the side wall and is arranged inside the box furnace, the load-bearing shaft comprises an inner shaft and a cooling system arranged on the outer wall of the inner shaft, and a contraction diameter is also arranged on the outside of the load-bearing shaft.

[0005] The box furnace is also provided with an air inlet valve and an air outlet valve.

[0006] The expansion diameter includes an ejection component, so that the expansion diameter can be expanded and contracted along the radial direction of the load-bearing shaft under the action of hydraulic pressure.

[0007] The load-bearing shaft is connected to the base through a bearing and is rotated by controlling a motor.

[0008] The temperature of the heating element is regulated by a controller.

[0009] The cooling system comprises a cooling pipe arranged on the outer wall of the inner shaft and a water inlet pipe and a water outlet pipe connected to the cooling pipe.

[0010] The bearing shaft and the box furnace are sealed by oil sealing.

[0011] Another object of the present invention is to provide an annealing method for improving the coil shape of a titanium strip, using the above-mentioned device for improving the coil shape of a titanium strip, comprising the following steps:

[0012] Step 1: Measure the distance from the outer surface of the titanium strip to the center of the roll, represented by D1, measure the distance from the inner surface of the titanium strip to the center of the roll, represented by D2, and then measure the width of the titanium strip, represented by D3;

[0013] Step 2: Place the core of the titanium strip coil parallel to the bearing shaft and install it into the box, so that one of the bearing shafts passes through the core, start the expansion diameter until the ejection device of the expansion diameter supports the inner surface of the titanium strip coil, and let the titanium strip coil rotate along the axial direction without slipping, and then put another titanium strip coil on the other bearing shaft in the same way;

[0014] Step 3: Close the furnace door and evacuate the furnace. When the vacuum degree reaches 5Pa, turn on the heating element and cooling system in the furnace to ensure that the temperature difference between the low temperature of the core and the high temperature of the curling edge of the titanium strip is maintained during the annealing process, accelerate the heat flow movement, and improve the annealing effect. When the temperature in the furnace reaches 400℃, stop evacuating the furnace, and fill argon gas into the furnace body from the air inlet valve. According to the sealing condition of the furnace chamber, adjust the amount of argon gas entering to keep the air pressure in the furnace at 20±5Pa; turn on the control motor to drive the titanium strip to rotate through the load-bearing shaft, and the rotation speed is controlled to Where v is the speed required for the titanium strip to roll, t is the time interval period; g is the acceleration of gravity;

[0015] Step 4: When the pressure in the furnace is stable, the temperature is raised for the second time from 400°C to 650-750°C. During the heating process, the pressure in the furnace is maintained at 20±5Pa. The heating rate is K1, K1 is controlled at 4-10°C / min, and the heat transfer efficiency of the titanium strip is K2, K2 is controlled at 2-6mm / min. If D3 / K1≤D1-D2, the heating time is based on (D1-D2) / K2; if D3 / K1≥D1-D2, the heating time is based on D3 / K2;

[0016] Step 5. After the heating time is over, turn off the heating element and let it cool with the furnace. The load-bearing shaft continues to drive the titanium coil to rotate until the titanium coil cools to below 50°C. Stop the rotation of the load-bearing shaft and turn off the cooling system. Open the air inlet valve and the air outlet valve. When the air pressure in the furnace is equal to the atmospheric pressure, open the furnace. After the diameter is reduced, take out the titanium coil to obtain a titanium coil with a good roll shape.

[0017] The present invention has the following advantages:

[0018] The device provided by the present invention is simple in design, easy to operate and has good use effect. During the annealing process of the titanium strip, a "low pressure-high pressure-sub-high pressure-sub-low pressure" heat flow cycle is spontaneously formed inside the furnace, which can effectively solve the problem that the traditional upright hood annealing furnace is prone to uneven heat flow during the heating process, resulting in different temperatures on the surface of the titanium coil and at the core of the titanium coil. The titanium strip produced by this method has a good roll shape, and the unevenness is ≤1.2% after annealing and natural expansion. The titanium strip can be directly cut into plates for use without subsequent straightening, plate stress relief annealing and other processes; the processing process is effectively shortened, bringing significant economic benefits to the enterprise. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the device of the present invention;

[0020] Figure 2 It is a structural diagram of the load-bearing shaft and the expansion diameter;

[0021] Figure 3 yes Figure 1 Structural diagram of the AA section;

[0022] Figure 4 This is a schematic diagram of measuring the titanium strip coil in step one.

[0023] In the figure: 1-titanium strip coil, 2-cooling system, 3-inner shaft, 4-ejection component, 5-base, 6-inlet valve, 7-outlet valve, 8-heating element, 9-baffle, 10-water outlet pipe, 11-water inlet pipe, 12-control motor, 13-furnace door, 14-bearing, 15-load-bearing shaft, 16-shrinking diameter. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is further described below through embodiments.

[0025] As shown in the figure, the device for improving the coil shape of titanium strip includes a box furnace, a base 5 with a load-bearing shaft 15 respectively arranged on both sides of the box furnace, and a heating element 8 distributed on the inner wall of the box furnace; the load-bearing shaft 15 passes through the side wall and is arranged inside the box furnace, the load-bearing shaft 15 includes an inner shaft 3 and a cooling system arranged on the outer wall of the inner shaft 3, and a shrinking diameter 16 is also arranged outside the load-bearing shaft 15.

[0026] The box furnace is also provided with an air inlet valve 6 and an air outlet valve 7. The expansion diameter 16 includes a ejection component 4, so that the expansion diameter 16 can be extended and retracted along the radial direction of the load-bearing shaft 15 under the action of hydraulic pressure. The load-bearing shaft 15 is connected to the base 5 through a bearing 14, and is rotated by controlling the motor 12. The heating element 8 controls the temperature through a controller. The cooling system includes a cooling pipe arranged on the outer wall of the inner shaft 3 and a water inlet pipe 11 and a water outlet pipe 10 connected to the cooling pipe. The sealing of the load-bearing shaft 15 and the box furnace adopts an oil seal.

[0027] Example 1

[0028] Take the annealing of a titanium strip coil with a grade of TA10, a weight of 10 tons, a coil width of 1050 mm, and a thickness of 6 mm as an example.

[0029] The device for improving the coil shape of titanium strip comprises the following steps:

[0030] Step 1: Measure the distance from the outer surface of the titanium strip to the center of the roll, which is 1500 mm, represented by D1, measure the distance from the inner surface of the titanium strip to the center of the roll, which is 254 mm, represented by D2, and then measure the width of the titanium strip, which is 1052 mm, represented by D3;

[0031] Step 2: Place the core of the titanium strip coil parallel to the bearing shaft and install it into the box, so that one of the bearing shafts passes through the core, start the expansion diameter until the ejection device of the expansion diameter supports the inner surface of the titanium strip coil, and let the titanium strip coil rotate along the axial direction without slipping, and then put another titanium strip coil on the other bearing shaft in the same way;

[0032] Step 3: Close the furnace door and evacuate the furnace. When the vacuum degree reaches 5Pa, turn on the heating element and cooling system in the furnace to ensure that the temperature difference between the low temperature of the core and the high temperature of the curling edge of the titanium strip is maintained during the annealing process, accelerate the heat flow movement, and improve the annealing effect. When the temperature in the furnace reaches 400℃, stop evacuating the furnace, and fill argon gas into the furnace body from the air inlet valve. According to the sealing condition of the furnace chamber, adjust the amount of argon gas entering to keep the air pressure in the furnace at 20Pa; turn on the control motor to drive the titanium strip to rotate through the load-bearing shaft, and the rotation speed is controlled to Where v is the speed required for the titanium strip to be rolled, t is the time interval period; g is the acceleration of gravity; t is set to 1s, v = 0.08m / s;

[0033] Step 4: When the pressure in the furnace is stable, the temperature is raised from 400°C to 700°C for the second time. During the heating process, the pressure in the furnace is kept at 20Pa. The heating rate is K1, K1 is controlled at 4°C / min, the heat transfer efficiency of the titanium strip is K2, K2 is controlled at 3mm / min, and the heating and holding time is 415min.

[0034] Step 5. After the heating time is over, turn off the heating element and let it cool with the furnace. The load-bearing shaft continues to drive the titanium coil to rotate until the titanium coil cools to below 50°C. Stop the rotation of the load-bearing shaft and turn off the cooling system. Open the air inlet valve and the air outlet valve. When the air pressure in the furnace is equal to the atmospheric pressure, open the furnace. After the diameter is reduced, take out the titanium coil to obtain a titanium coil with a good roll shape.

[0035] The titanium strip coil produced by the present invention has a good coil shape, and the unevenness after annealing and natural unfolding is ≤1.2%. The titanium strip coil can be directly used by cutting into plates, reducing the subsequent press correction, plate stress relief annealing and other processes, and can obtain obvious economic benefits.

[0036] Example 2

[0037] Take the annealing of a titanium strip coil with a grade of TA1, a weight of 8 tons, a coil width of 1050 mm, and a thickness of 6 mm as an example.

[0038] The device for improving the coil shape of titanium strip comprises the following steps:

[0039] Step 1: Measure the distance from the outer surface of the titanium strip to the center of the roll, which is 1200 mm, represented by D1, measure the distance from the inner surface of the titanium strip to the center of the roll, which is 288 mm, represented by D2, and then measure the width of the titanium strip, which is 1052 mm, represented by D3;

[0040] Step 2: Place the core of the titanium strip coil parallel to the bearing shaft and install it into the box, so that one of the bearing shafts passes through the core, start the expansion diameter until the ejection device of the expansion diameter supports the inner surface of the titanium strip coil, and let the titanium strip coil rotate along the axial direction without slipping, and then put another titanium strip coil on the other bearing shaft in the same way;

[0041] Step 3: Close the furnace door and evacuate the furnace. When the vacuum degree reaches 5Pa, turn on the heating element and cooling system in the furnace to ensure that the temperature difference between the low temperature of the core and the high temperature of the curling edge of the titanium strip is maintained during the annealing process, accelerate the heat flow movement, and improve the annealing effect. When the temperature in the furnace reaches 400℃, stop evacuating the furnace, and fill argon gas into the furnace body from the air inlet valve. According to the sealing condition of the furnace chamber, adjust the amount of argon gas entering to keep the air pressure in the furnace at 20±5Pa; turn on the control motor to drive the titanium strip to rotate through the load-bearing shaft, and the rotation speed is controlled to Where v is the speed required for the titanium strip to be rolled, t is the time interval period; g is the acceleration of gravity; t is set to 1s, v = 0.08m / s.

[0042] Step 4: When the pressure in the furnace is stable, the temperature is raised from 400°C to 650°C for the second time. During the heating process, the pressure in the furnace is kept at 20±5Pa. The heating rate is K1, K1 is controlled at 6°C / min, the heat transfer efficiency of the titanium strip is K2, K2 is controlled at 2mm / min, and the heating and holding time is 456min.

[0043] Step 5. After the heating time is over, turn off the heating element and let it cool with the furnace. The load-bearing shaft continues to drive the titanium coil to rotate until the titanium coil cools to below 50°C. Stop the rotation of the load-bearing shaft and turn off the cooling system. Open the air inlet valve and the air outlet valve. When the air pressure in the furnace is equal to the atmospheric pressure, open the furnace. After the diameter is reduced, take out the titanium coil to obtain a titanium coil with a good roll shape.

[0044] The titanium strip coil produced by the present invention has a good coil shape, and the unevenness after annealing and natural unfolding is ≤1.2%. The titanium strip coil can be directly used by cutting into plates, reducing the subsequent press correction, plate stress relief annealing and other processes, and can obtain obvious economic benefits.

[0045] Example 3

[0046] Take the annealing of a titanium strip coil with a grade of TA2, a weight of 6 tons, a coil width of 800 mm, and a thickness of 6 mm as an example.

[0047] The device for improving the coil shape of titanium strip comprises the following steps:

[0048] Step 1: Measure the distance from the outer surface of the titanium strip to the center of the roll, which is 1000 mm, represented by D1, measure the distance from the inner surface of the titanium strip to the center of the roll, which is 272 mm, represented by D2, and then measure the width of the titanium strip, which is 804 mm, represented by D3;

[0049] Step 2: Place the core of the titanium strip coil parallel to the bearing shaft and install it into the box, so that one of the bearing shafts passes through the core, start the expansion diameter until the ejection device of the expansion diameter supports the inner surface of the titanium strip coil, and let the titanium strip coil rotate along the axial direction without slipping, and then put another titanium strip coil on the other bearing shaft in the same way;

[0050] Step 3: Close the furnace door and evacuate the furnace. When the vacuum degree reaches 5Pa, turn on the heating element and cooling system in the furnace to ensure that the temperature difference between the low temperature of the core and the high temperature of the curling edge of the titanium strip is maintained during the annealing process, accelerate the heat flow movement, and improve the annealing effect. When the temperature in the furnace reaches 400℃, stop evacuating the furnace, and fill argon gas into the furnace body from the air inlet valve. According to the sealing condition of the furnace chamber, adjust the amount of argon gas entering to keep the air pressure in the furnace at 20±5Pa; turn on the control motor to drive the titanium strip to rotate through the load-bearing shaft, and the rotation speed is controlled to Where v is the speed required for the titanium strip to be rolled, t is the time interval period; g is the acceleration of gravity; t is set to 1s, v = 0.08m / s;

[0051] Step 4: When the pressure in the furnace is stable, the temperature is raised from 400°C to 750°C for the second time. During the heating process, the pressure in the furnace is kept at 20±5Pa. The heating rate is K1, K1 is controlled at 10°C / min, the heat transfer efficiency of the titanium strip is K2, K2 is controlled at 6mm / min, and the heating and holding time is 122min.

[0052] Step 5. After the heating time is over, turn off the heating element and let it cool with the furnace. The load-bearing shaft continues to drive the titanium coil to rotate until the titanium coil cools to below 50°C. Stop the rotation of the load-bearing shaft and turn off the cooling system. Open the air inlet valve and the air outlet valve. When the air pressure in the furnace is equal to the atmospheric pressure, open the furnace. After the diameter is reduced, take out the titanium coil to obtain a titanium coil with a good roll shape.

[0053] The titanium strip coil produced by the present invention has a good coil shape, and the unevenness after annealing and natural unfolding is ≤1.2%. The titanium strip coil can be directly used by cutting into plates, reducing the subsequent press correction, plate stress relief annealing and other processes, and can obtain obvious economic benefits.

[0054] The above description is only a preferred embodiment of the present invention and does not impose any limitation on the present invention. Any simple modification, change and equivalent structural changes to the above embodiments based on the technical essence of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A device for improving the roll shape of a titanium strip, characterized in that: It includes a box furnace, bases with load-bearing shafts respectively arranged on the two outer sides of the box furnace, and heating elements distributed on the inner wall of the box furnace; the load-bearing shaft passes through the side wall and is arranged inside the box furnace, the load-bearing shaft includes an inner shaft and a cooling system arranged on the outer wall of the inner shaft, and a contraction diameter is also arranged outside the load-bearing shaft; The box furnace is also provided with an air inlet valve and an air outlet valve; The expansion diameter includes a push-out component, so that the expansion diameter can be expanded and contracted along the radial direction of the load-bearing shaft under the action of hydraulic pressure; The load-bearing shaft is connected to the base through a bearing and rotates by controlling the motor; The heating element realizes temperature regulation through a controller; The cooling system comprises a cooling pipe arranged on the outer wall of the inner shaft and a water inlet pipe and a water outlet pipe connected to the cooling pipe; The bearing shaft and the box furnace are sealed by oil sealing.

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