A method for controlling the flattening of titanium material to prevent scratching defects

Abstract

The present application provides a kind of control titanium material scratch defect flattening method, comprising the following steps: S1: titanium material is carried out and is worn;S2: after titanium material wearing ends, the operating parameter of flattening machine is set;S3: in turn, titanium material is opened, flattened and is coiled;S4: whether titanium material appears scratch defect, if appears, the operating parameter of flattening machine is reset, if not appears, continue to open, flatten and coiling to titanium material;S5: repeat step S4 until the titanium material is completed and is cut off tail flattening.The present application is produced by using flattening mode to titanium material, solves the technical problem of scratch defect caused by " turtle back " defect of titanium raw material roll scraping work roll, reduces the production cost, improves the production efficiency of titanium;The method of the present application solves the technical problem that the unit is prone to scratch defect when repairing titanium tower shape by cold working under the existing flattening unit operating conditions.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgical rolling, and in particular relates to a flattening method for controlling scratch defects of titanium materials. Background Art

[0002] Titanium products have excellent corrosion resistance, extremely high specific strength, and biocompatibility, and are widely used in industries such as military, medical equipment, aerospace, and scientific research and navigation. To leverage the region's abundant titanium resources and promote the development of the titanium industry, many steel mills have begun researching the rolling of titanium products. Due to the difficulty of titanium rolling, the coiled titanium coils have a serious towering shape that cannot meet the user's appearance quality requirements, requiring a leveling process to repair the towering shape. However, during the leveling repair process, the titanium coils suffer from a serious "turtle back" defect, resulting in the fixed opening between the upper and lower leveling work rolls being at the maximum position. The upper surface of the titanium material will still scrape against the upper work roll, resulting in serious scratches. The difficult process restrictions once affected the production and development of titanium products. Summary of the Invention

[0003] In view of the above problems, the present invention proposes a method for leveling titanium materials to control scratch defects.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A method for leveling titanium material scratch defects, comprising the following steps:

[0006] S1: threading the titanium material;

[0007] S2: After the titanium strip is threaded, set the operating parameters of the leveler;

[0008] S3: uncoiling, flattening and coiling the titanium material in sequence;

[0009] S4: Determine whether the titanium material has scratch defects. If so, reset the operating parameters of the leveler. If not, continue to unwind, level and coil the titanium material.

[0010] S5: Repeat step S4 until the titanium material is flattened and the tail of the strip is cut off.

[0011] Preferably, step S1 includes:

[0012] When the titanium material head enters the leveling mill, the roller gap is controlled to close and the titanium material is pressed by the leveling work roll;

[0013] The belt is threaded after the roller gap is closed.

[0014] Preferably, a testing step is further included before step S1:

[0015] In the rewinding mode, the titanium material is uncoiled, rewound and coiled with the flat work roll at the maximum fixed opening;

[0016] Observe whether the titanium material has scratch defects. If so, switch the rewinding mode to the flattening mode and execute step S1. If not, unwind, rewind and coil the titanium material at the maximum fixed opening.

[0017] Preferably, setting the operating parameters of the leveling machine includes the following steps:

[0018] Set the unwinding tension;

[0019] Set the winding tension;

[0020] Setting the temper rolling force;

[0021] Set positive or negative bending roll force;

[0022] Set the shifting position of the leveling work roll.

[0023] Preferably, the uncoiling tension is 5t to 15t, the coiling tension is 10t to 30t, the temper rolling force is 120t to 200t, the positive bending roll force is 0 to 70t, and the negative bending roll force is 0 to 70t.

[0024] Preferably, setting the shifting position of the leveling work roll includes:

[0025] Move the upper roller 150 mm from the center line of the leveler to the transmission side, and then move the lower roller 150 mm from the center line of the leveler to the operating side.

[0026] Preferably, step S3 includes:

[0027] When rolling, observe whether the center line of the titanium material is consistent with the center line of the leveler;

[0028] If they are inconsistent, adjust the position of the uncoiler drum horizontally;

[0029] If they agree, continue scrolling.

[0030] Preferably, horizontally adjusting the position of the uncoiler drum comprises the following steps:

[0031] Reduce the leveling speed of titanium;

[0032] Move the position of the uncoiler drum horizontally several times to align it with the center line of the leveler.

[0033] Preferably, step S5 includes:

[0034] When the tail of the titanium material leaves the uncoiler drum, the unit stops running;

[0035] The leveler is in the roll gap closed state. When the strip tail reaches the leveler entrance, the leveler roll gap is opened to cut off the strip tail.

[0036] Beneficial effects of the present invention:

[0037] 1. The present invention adopts a flattening method to produce titanium materials, thereby solving the technical problem of scratches caused by the "turtle back" defect of the titanium raw material coil scraping the upper working roller, reducing production costs and improving the production efficiency of titanium materials;

[0038] 2. The method of the present invention utilizes the operating conditions of the existing leveling mill unit. By adopting the leveling mode to produce titanium materials, using a smaller rolling force for leveling titanium materials, and using a +0.04mm positive convexity control for the roller profile of the leveling work roll, etc., it solves the technical problem that the unit is prone to scratch defects during cold working to repair the tower-shaped titanium materials.

[0039] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0041] Figure 1 A schematic flow chart of a method for controlling scratch defects in titanium materials according to the present invention is shown;

[0042] Figure 2 A schematic diagram showing the positions of the leveling upper working roll of the present invention in the rewinding mode and the leveling mode when the roll diameter is at the minimum value;

[0043] Figure 3 A schematic diagram showing the positions of the leveling lower working roll of the present invention in the rewinding mode and the leveling mode when the roll diameter is at the minimum value;

[0044] Figure 4 The equivalent roll crown diagram of the work rolls at different roll shifting positions of the present invention is shown;

[0045] Figure 5 A schematic diagram of the positive crown roll profile of the smooth working roll of the present invention is shown. DETAILED DESCRIPTION

[0046] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings 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 making creative efforts shall fall within the scope of protection of the present invention.

[0047] A method for controlling scratch defects in titanium materials, such as Figure 1 As shown, the following steps are included:

[0048] S1: threading the titanium material;

[0049] S2: After the titanium strip is threaded, set the operating parameters of the leveler;

[0050] S3: uncoiling, flattening and coiling the titanium material in sequence;

[0051] S4: Determine whether the titanium material has scratch defects. If so, reset the operating parameters of the leveler. If not, continue to unwind, level and coil the titanium material.

[0052] S5: Repeat step S4 until the titanium material is flattened and the tail of the strip is cut off.

[0053] It should be noted that steps S1 to S5 are the working process of producing titanium raw material coils using a flattening mode. Its function is first to flatten the titanium raw material coils with "turtle back" defects, and at the same time to avoid scratch defects on the surface of the titanium material.

[0054] Furthermore, step S1 specifically includes:

[0055] When the titanium material head enters the leveling mill, the roller gap is controlled to close and the titanium material is pressed by the leveling work roll;

[0056] The belt is threaded after the roller gap is closed.

[0057] It should be noted that after the roll gap of the leveling mill is closed, the speed at which the titanium material continues to thread the strip will be consistent with the linear speed of the upper and lower working rolls of the leveling mill, achieving synchronous rotation and effectively solving the problem of scratch defects on the titanium material.

[0058] Furthermore, a testing step is also included before step S1:

[0059] In the rewinding mode, when the flat work roll is at its maximum diameter of 550mm, the fixed opening between the upper and lower work rolls is 55mm; when the flat work roll is at its minimum diameter of 500mm, the fixed opening between the upper and lower work rolls is 105mm. The titanium material is uncoiled, recoiled, and coiled with the flat work roll at its maximum fixed opening.

[0060] Observe whether the titanium material has scratch defects. If so, switch the rewinding mode to the flattening mode and execute step S1. If not, unwind, rewind and coil the titanium material at the maximum fixed opening (generally 105 mm).

[0061] like Figure 2 As shown, the upper roll of the leveling machine includes 1 supporting roll and 1 working roll. In the leveling mode, the supporting roll and the working roll are in a vertically pressed state. When the supporting roll is in the minimum roll diameter state, the diameter is Ф1100mm, and when the working roll is in the minimum roll diameter state, the diameter is Ф500mm, and the working roll is located at the rolling line; then in the rewinding mode, the supporting roll is 1190mm away from the rolling line, and the working roll is 55mm away from the rolling line.

[0062] like Figure 3 As shown, the lower roll of the leveling mill also includes 1 support roll and 1 working roll. The position settings in the leveling mode are the same. The difference is that in the rewinding mode, the working roll is 50 mm away from the rolling line, and the support roll is 1185 mm away from the rolling line.

[0063] Combine Figure 2 and Figure 3 In titanium production using the rewinding mode, the maximum gap between the upper and lower work rolls is 105mm, while in the leveling mode, the gap is closed. The "turtle back" height of the titanium material can reach 200mm in severe cases. This causes scraping between the highest point in the middle of the titanium material and the upper work roll. When the friction between the titanium material and the upper work roll is unable to drive the work roll while the titanium material is in motion, stripe-shaped scratches will appear on the titanium material's upper surface where it contacts the upper work roll. Therefore, a test step is required to determine whether rewinding mode is suitable for production.

[0064] Furthermore, setting the operating parameters of the leveling machine includes the following steps:

[0065] Set the unwinding tension to 5t~15t;

[0066] Set the winding tension to 10t~30t;

[0067] Set the temper rolling force to 120t~200t;

[0068] Set the positive bending roll force to 0~70t and the negative bending roll force to 0~70t. Generally, the positive bending roll force is recorded as a "+" value and the negative bending roll force is recorded as a "-" value, so the bending roll force of the leveling machine is -70t~+70t.

[0069] Setting the shifting position of the leveling work roll includes:

[0070] Move the upper roller 150 mm from the center line of the leveler to the transmission side, and then move the lower roller 150 mm from the center line of the leveler to the operating side.

[0071] It should be noted that if the distance moved toward the transmission side is recorded as a "-" value and the distance moved toward the operating side is recorded as a "+" value, then the range of the working roll shifting position is -150mm to +150mm.

[0072] It should be further explained that when setting the operating parameters of the leveling mill, it is necessary to ensure that the tilting function of the roller is adjusted within the range of ±50 tons, where the "+" value represents a large rolling force on the transmission side and the "-" value represents a large rolling force on the operating side.

[0073] It should be noted that the leveling machine uses a smaller rolling force for leveling, which solves the roller mark defect caused by the upper and lower rollers easily sticking to the meat.

[0074] like Figure 4 As shown, the horizontal axis is the movement amount of the upper and lower working rolls of the leveling machine, and the vertical axis is the equivalent crown of the working roll. It can be seen from the figure that when the upper working roll of the leveling machine is at the position of -150mm on the transmission side and the lower working roll of the leveling machine is at the position of +150mm on the operating side, the corresponding equivalent crown is +0.04mm; when the upper working roll of the leveling machine is at the position of +150mm on the operating side and the lower working roll of the leveling machine is at the position of -150mm on the transmission side, the corresponding equivalent crown is -0.12mm. In addition, the CVC roller profile curve adopted by the upper and lower working rolls of the leveling machine can realize the online adjustment of the roller profile crown of the working roll according to the characteristics of the wave defects of the raw material and the roller shifting function of the leveling machine: if there are double-sided waves in the raw material, the roller profile crown of the leveling work roll needs to adopt positive crown; if there are medium waves in the raw material, the roller profile crown of the leveling work roll needs to adopt negative crown.

[0075] like Figure 5 As shown in the figure, the left side is the transmission side, and the right side is the operating side. When the leveling upper work roll moves toward the operating side, the corresponding value is a "+" value. According to the CVC roll profile characteristics, the leveling lower work roll should move toward the transmission side by the same amount, and the corresponding value is a "-" value. The roll profile of the leveling work roll is negative crown, which is suitable for improving the wave defects in the raw material.

[0076] Furthermore, step S3 includes:

[0077] Observe whether the center line of the titanium material is consistent with the center line of the temper mill when coiling up;

[0078] If not, horizontally adjust the position of the uncoiler reel;

[0079] If yes, continue coiling up.

[0080] Further, horizontally adjusting the position of the uncoiler reel comprises the following steps:

[0081] Lower the speed of the titanium material tempering;

[0082] Horizontally move the position of the uncoiler reel multiple times to align the center line of the temper mill.

[0083] It should be noted that the entry operator needs to ensure that the center line of the steel coil is basically consistent with the center line of the unit when coiling up, and corresponding adjustment is made according to the offset of the tower-shaped defect during production operation. During production, it can be observed through the monitoring screen, and a scale will be installed on both sides of the monitoring screen. When coiling up, the center line of the outermost circle of the steel coil is aligned with the center line of the unit. The edge of the steel coil with a tower-shaped defect is used as a reference value for manual correction corresponding to the scale value on the monitoring television.

[0084] Further, step S5 comprises:

[0085] When the tail of the titanium material leaves the uncoiler reel, the unit stops running;

[0086] The temper mill is in a closed roll gap state, the tail reaches the inlet of the temper mill, and the roll gap of the temper mill is opened to cut off the tail.

[0087] It should be noted that the method of the present application has the following benefits after implementation:

[0088] The method of the present application utilizes the existing temper mill unit operating conditions, and solves the control problem of the unit being prone to scratch defects when cold working and repairing titanium tower-shaped defects by adopting the following technical measures: producing titanium by tempering mode, using smaller rolling force for tempering titanium, and using 0.04mm positive crown control for the crown of the tempering work roll. The flatness of the titanium plate after tempering is reduced from 60-150mm / m before tempering to ≤15mm / m, and the scratch defect of the titanium product after implementation is significantly reduced from 50% to within 2%, the price difference between the good product and the degraded product is 20000 yuan / ton, and the unit has produced 0.4 million tons during the implementation period, directly creating economic benefits of 23 million yuan.

[0089] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for leveling titanium material scratch defects, characterized in that: The following steps are involved: S1: threading the titanium material; Before step S1, a test step is also included: In the rewinding mode, the titanium material is uncoiled, rewound and coiled with the flat work roll at the maximum fixed opening; Observe whether the titanium material has scratch defects. If so, switch the rewinding mode to the flattening mode and execute step S1. If not, unwind, rewind, and coil the titanium material at the maximum fixed opening. S2: After the titanium strip is threaded, set the operating parameters of the leveler, including: Set the unwinding tension to 5~15t; Set the winding tension to 10~30t; Set the temper rolling force to 120t~200t; Set the negative bending roll force to 0~70t; Set the leveling work roll shifting position, including moving the upper roll 150mm from the center line of the leveling mill to the drive side, and then moving the lower roll 150mm from the center line of the leveling mill to the operating side; S3: Uncoiling, flattening and coiling the titanium material in sequence, including: When rolling, observe whether the center line of the titanium material is consistent with the center line of the leveler; If they are inconsistent, adjust the position of the uncoiler drum horizontally; If they agree, continue scrolling; S4: Determine whether the titanium material has scratch defects. If so, reset the operating parameters of the leveler. If not, continue to unwind, level and coil the titanium material. S5: Repeat step S4 until the titanium material is flattened and the tail of the strip is cut off.

2. A method for leveling titanium material scratch defects according to claim 1, characterized in that: Step S1 includes: When the titanium material head enters the leveling mill, the roller gap is controlled to close and the titanium material is pressed by the leveling work roll; The belt is threaded after the roller gap is closed.

3. A method for leveling titanium material scratch defects according to claim 1, characterized in that: Horizontally adjusting the position of the uncoiler drum comprises the following steps: Reduce the leveling speed of titanium; Move the position of the uncoiler drum horizontally several times to align it with the center line of the leveler.

4. A method for leveling titanium material scratch defects according to any one of claims 1 to 3, characterized in that: Step S5 includes: When the tail of the titanium material leaves the uncoiler drum, the unit stops running; The leveler is in the roll gap closed state. When the strip tail reaches the leveler entrance, the leveler roll gap is opened to cut off the strip tail.

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