A hot rolling method capable of controlling the thickness accuracy of titanium plates

Abstract

The present invention relates to the technical field related to titanium plate processing, specifically a hot rolling method capable of controlling the thickness accuracy of titanium plates, comprising the following steps: Step 1, first loading the titanium slab to be hot-rolled into a roller furnace for heating and heat preservation; Step 2, after reaching the temperature, taking the slab out of the furnace; Step 3, the roller conveys the heated titanium slab to a four-roll reversible hot rolling mill for reciprocating hot rolling and thinning; Step 4, when the titanium plate is rolled to a thickness close to that of the finished product, starting the variable speed rolling mode and dynamically adjusting the rolling force during the rolling process. The present invention creatively introduces variable rolling speed and variable rolling force control in the rolling process, achieving dynamic adjustment and compensation over the entire length of the titanium plate. This solves the technical problem of large deformation resistance and difficulty in deformation caused by excessively rapid temperature drop at the end, resulting in large rolling thickness difference.

Description

Technical Field

[0001] The invention relates to the technical field related to titanium plate processing, and in particular to a hot rolling processing method capable of controlling the thickness precision of the titanium plate. Background Art

[0002] During the hot rolling thinning process of the titanium plate, the temperature of the surface and surrounding parts of the heated thick slab drops rapidly as the titanium plate is thinned, especially the surrounding parts. The thinning in the width direction is basically consistent due to the uniform pressure of the roller surface, so the thickness deviation after final rolling is small. At the two ends in the length direction, the temperature shows a gradually decreasing gradient from the inside to the outside. Therefore, the closer to the end, the greater the deformation resistance of the titanium plate. Under the same rolling force, the closer to the end, the less the thickness thinning deformation. The titanium plate after hot rolling shows the characteristics of "thick at both ends and thin in the middle". The thickness difference of the same plate is basically at the level of 0.4-0.6mm. This is the main reason for the different thickness of the same plate of hot-rolled titanium plate. Up to now, there is no particularly good technical means for hot rolling of titanium plates at home and abroad (the hot rolling caused by the present invention is sheet hot rolling, not coil hot rolling) to reduce the thickness difference of hot-rolled titanium plates in the length direction and control the rolling accuracy of titanium plates. Summary of the Invention

[0003] The object of the present invention is to provide a hot rolling method capable of controlling the thickness accuracy of titanium plates, so as to solve the problems raised in the above-mentioned background technology.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A hot rolling method capable of controlling the thickness accuracy of a titanium plate comprises the following steps:

[0006] Step 1: The titanium slab to be hot-rolled is first placed in a roller furnace for heating and insulation;

[0007] Step 2: After reaching the temperature, remove from the oven;

[0008] Step 3: The roller conveys the heated titanium slab to a four-roll reversible hot rolling mill for reciprocating hot rolling and thinning;

[0009] Step 4: When the titanium plate is rolled to a thickness close to that of the finished product, the variable speed rolling mode is started, and the rolling force is dynamically adjusted during the rolling process.

[0010] As a further solution of the present invention: the heating and holding temperature of the titanium slab to be hot-rolled in the roller furnace is 750-920°C.

[0011] As a further solution of the present invention: the heating and holding time of the titanium slab to be hot-rolled in the roller furnace is 30-45 minutes.

[0012] As a further solution of the present invention: the roller speed of the four-roller reversible hot rolling mill is 8-12 r / min, that is, the travel speed is 8-12 m / min.

[0013] As a further solution of the present invention: the linear increase rate of the rolling force during the rolling process is +200-300 N / s.

[0014] As a further solution of the present invention, the titanium slab is reciprocated and rolled twice in the four-roll reversible hot rolling mill.

[0015] As a further solution of the present invention: after the rolling parameters are adjusted, the titanium plate is reciprocated and rolled twice.

[0016] As a further solution of the present invention, the position where the rolling force changes is 500 mm away from both end heads.

[0017] Compared with the existing technology, the present invention has the following advantages: 1. It has a novel design and creatively introduces variable rolling speed and variable rolling force control during the rolling process, achieving dynamic adjustment and compensation over the entire length of the titanium plate. 2. It solves the technical problem of large thickness differences caused by excessively rapid temperature drop at the end, resulting in high deformation resistance and difficulty in deformation.

[0018] Secondly, the temperature gradient distribution of the titanium plate causes a performance gradient difference. Therefore, the rolling process adopts the traditional constant rolling force and rolling speed, which cannot continuously control the thickness difference caused by the change of plate performance. In the actual rolling process, the titanium plate is continuously moving forward on the roller, and the rolling speed is relatively fast, while the rolling force feedback takes time. Therefore, while performing dynamic rolling force distribution adjustment, it is necessary to give the electronic valve control unit that delivers the rolling force a start-up response time, that is, to give the rolling force adjustment a certain distribution time before the rolling force can be increased. This process requires the plate to dynamically reduce its travel speed on the roller, so that the rolling force of the titanium plate near the end area gradually increases, so that the rolling force change and the material performance gradient change are synchronized. In this way, the dynamic distribution mechanism of the rolling force and the speed can be coordinated throughout the entire length range, thereby achieving precise control of the thickness of the hot-rolled titanium plate throughout the entire length range;

[0019] In addition, this method for controlling the thickness accuracy of hot-rolled titanium plates does not require the addition of specific hardware facilities. It can be achieved by adjusting the process parameters of the control program. It is simple, economical, and efficient, and is an excellent way to promote industrial application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The figure is a schematic diagram of the rolling process of a titanium slab in one embodiment of a hot rolling method capable of controlling the thickness accuracy of the titanium plate.

[0021] Figure 2This is a schematic diagram of the thickness distribution of TA3G, 9*1250*7500 hot-rolled titanium plate in one embodiment of a hot rolling processing method that can control the thickness accuracy of the titanium plate.

[0022] Figure 3 This is a schematic diagram of the thickness distribution of TC4,10*1040*4500 hot-rolled titanium plate in one embodiment of a hot rolling processing method capable of controlling the thickness accuracy of the titanium plate. DETAILED DESCRIPTION

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 are within the scope of protection of the present invention.

[0024] In addition, when an element in the present invention is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0025] See also Figure 1-Figure 3 In an embodiment of the present invention, a hot rolling method capable of controlling the thickness accuracy of a titanium plate comprises the following steps:

[0026] Step 1: The titanium slab to be hot-rolled is first placed in a roller furnace for heating and insulation;

[0027] Step 2: After reaching the temperature, remove from the oven;

[0028] Step 3: The roller conveys the heated titanium slab to a four-roll reversible hot rolling mill for reciprocating hot rolling and thinning;

[0029] Step 4: When the titanium plate is rolled to a thickness close to that of the finished product, the variable speed rolling mode is started, and the rolling force is dynamically adjusted during the rolling process.

[0030] See also Figure 1The specific process is as follows: the titanium plate enters the roller from one side at a constant speed, is rolled and thinned, and is rolled back and forth for several times. In the last few rolling passes close to the finished product, the rolling speed and rolling force are variably adjusted. That is: when the titanium plate moves to near the tail end, the speed of the titanium plate is linearly reduced, and the rolling force is linearly increased at the same time. The increase in rolling force balances the increase in deformation resistance at the end, thereby increasing the amount of rolling thinning and reducing the thickness gradient distribution at the end of the titanium plate. In this way, after multiple reciprocating rollings, the thickness gradient distribution at the end of the titanium plate is gradually eliminated, and the thickness of the entire titanium plate is precisely controlled across all sizes, thereby obtaining a hot-rolled titanium plate with uniform thickness.

[0031] The heating and holding temperature of the titanium slab to be hot-rolled in the roller furnace is 750-920°C.

[0032] The heating and holding time of the titanium slab to be hot-rolled in the roller furnace is 30-45 minutes.

[0033] The roller speed of the four-roll reversible hot rolling mill is 8-12 r / min, that is, the travel speed is 8-12 m / min.

[0034] The linear increase rate of rolling force during the rolling process is +200-300N / s.

[0035] The titanium slab is rolled back and forth twice in the four-roll reversible hot rolling mill.

[0036] After the rolling parameters were adjusted, the number of reciprocating rolling of the titanium plate was 2 times.

[0037] The position where the rolling force changes is 500 mm away from both end heads.

[0038] Example 1

[0039] TA3G, slab 45*1250*1500mm, kept at 750℃ for 45 minutes, taken out of the furnace after reaching the temperature, and reciprocating rolling, the roller speed is 12r / min (ie: converted to a travel speed of 12m / min); after two reciprocating rollings, the slab size is 15*1250*4500mm. At this time, at a distance of 500mm from both ends, the control program is started to linearly adjust the roller speed to reduce, and the rolling force is increased by synchronous linear adjustment. The linear increase rate of the rolling force is +200N / s. According to such rolling adjustment parameters, reciprocating rolling is performed twice to obtain the required 9*1250*7500 hot-rolled titanium plate. Measure the thickness of the titanium plate at different positions as follows Figure 2 The thickness distribution across the entire plate surface is characterized by thicker ends, thinner middle, and thinner edges. The tolerance within the same plate is within 0.17mm, which is significantly smaller than the tolerance band of the same thickness plate produced by traditional TA3G processing.

[0040] Example 2

[0041] TC4, slab 30*1040*1500mm, kept at 920℃ for 30 minutes, taken out of the furnace after reaching the temperature, and reciprocating rolling, the roller speed is 8r / min (ie: converted to a travel speed of 8m / min); after reciprocating rolling twice, the slab size is 15*1040*3000mm. At this time, at a distance of 500mm from both ends, the control program is started to linearly adjust the roller speed to reduce, and synchronously linearly adjust to increase the rolling force. The linear increase rate of the rolling force is +300N / s. According to such rolling adjustment parameters, reciprocating rolling is performed twice to obtain the required 10*1040*4500 hot-rolled titanium plate. Measure the thickness of the titanium plate at different positions as follows Figure 3 The thickness distribution across the entire plate surface is characterized by thicker ends, thinner middle, and thinner edges. The tolerance within the same plate is within 0.22mm, which is significantly smaller than the tolerance band of traditionally processed TA3G plates of the same thickness.

[0042] In summary, the present invention creatively introduces variable rolling speed and variable rolling force control during the rolling process, achieving dynamic adjustment and compensation over the entire length of the titanium plate. This solves the technical problem of large thickness differences caused by excessively rapid temperature drop at the end, resulting in high deformation resistance and difficulty in deformation.

[0043] Secondly, the temperature gradient distribution of the titanium plate causes a performance gradient difference. Therefore, the rolling process adopts the traditional constant rolling force and rolling speed, which cannot continuously control the thickness difference caused by the change of plate performance. In the actual rolling process, the titanium plate is continuously moving forward on the roller, and the rolling speed is relatively fast, while the rolling force feedback takes time. Therefore, while performing dynamic rolling force distribution adjustment, it is necessary to give the electronic valve control unit that delivers the rolling force a start-up response time, that is, to give the rolling force adjustment a certain distribution time before the rolling force can be increased. This process requires the plate to dynamically reduce its travel speed on the roller, so that the rolling force of the titanium plate near the end area gradually increases, so that the rolling force change and the material performance gradient change are synchronized. In this way, the dynamic distribution mechanism of the rolling force and the speed can be coordinated throughout the entire length range, thereby achieving precise control of the thickness of the hot-rolled titanium plate throughout the entire length range;

[0044] In addition, this method for controlling the thickness accuracy of hot-rolled titanium plates does not require the addition of specific hardware facilities. It can be achieved by adjusting the process parameters of the control program. It is simple, economical, and efficient, and is an excellent way to promote industrial application scenarios.

[0045] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0046] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A hot rolling method capable of controlling the thickness accuracy of titanium plates, characterized in that: The following steps are involved: Step 1: The titanium slab to be hot-rolled is first placed in a roller furnace for heating and insulation; Step 2: After reaching the temperature, remove from the oven; Step 3: The roller conveys the heated titanium slab to a four-roll reversible hot rolling mill for reciprocating hot rolling and thinning; Step 4: When the titanium plate is rolled to a thickness close to that of the finished product, the variable speed rolling mode is started, and the rolling force is dynamically adjusted during the rolling process; The position where the rolling force changes is 500 mm away from both end heads, and the linear increase rate of the rolling force during the rolling process is +200-300 N / s.

2. A hot rolling method capable of controlling the thickness accuracy of titanium plates according to claim 1, characterized in that: The heating and holding temperature of the titanium slab to be hot-rolled in the roller furnace is 750-920°C.

3. The hot rolling method capable of controlling the thickness accuracy of titanium plates according to claim 1, characterized in that: The heating and holding time of the titanium slab to be hot-rolled in the roller furnace is 30-45 minutes.

4. The hot rolling method capable of controlling the thickness accuracy of titanium plates according to claim 1, characterized in that: The roller speed of the four-roll reversible hot rolling mill is 8-12 r / min, that is, the travel speed is 8-12 m / min.

5. The hot rolling method capable of controlling the thickness accuracy of titanium plates according to claim 1, characterized in that: The titanium slab is rolled back and forth twice in the four-roll reversible hot rolling mill.

6. The hot rolling method capable of controlling the thickness accuracy of titanium plates according to claim 1, characterized in that: After the rolling parameters were adjusted, the number of reciprocating rolling of the titanium plate was 2 times.

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