CN110465561A - A kind of strong technique of hot-strip leveling - Google Patents

Abstract

The invention belongs to the field of hot-rolled strip steel finishing, and relates to a hot-rolled strip steel leveling process, in which the hot-rolled strip steel passes through a roller leveler, a leveler, a first tension device, a tension leveler and a second The tension device adopts the combination of roller straightening, leveling and tension leveling to eliminate the shape defects of the strip, improve the surface quality, improve the mechanical properties, reduce the residual stress level, and increase the composition rate of the unit; the tension device is a tension leveler The leveler and the tempering machine provide sufficient tension, which is beneficial to strip threading and shape control, and improves the yield. The roll leveler can perform preliminary shape control on the hot-rolled strip, and the cooperation of the tempering machine, tension device and tension leveler The use can eliminate the shape defects of thin strip steel and improve the mechanical properties of strip steel.

Description

A hot-rolled strip leveling process

technical field

The invention belongs to the field of hot-rolled strip steel finishing, and relates to a hot-rolled strip steel leveling process, in particular to a leveling and leveling process suitable for hot-rolled high-strength steel and hot-rolled thin strip steel finishing.

Background technique

With the maturation and improvement of hot rolling endless rolling technology, the current production limit thickness of hot rolled strip has been reduced to 0.6mm~0.8mm. It is easy to be affected by factors such as roll deformation and uneven cooling to cause large plate shape defects. In addition, the high-strength steel and ultra-high-strength steel produced by adding alloy elements or using TMCP technology will also be affected by factors such as roll deformation and uneven cooling during the hot rolling production process, resulting in plate shape defects and uneven distribution of internal residual stress. . In order to meet the requirements of downstream customers and downstream production processes such as pickling, cold rolling, and hot-plate galvanizing on the shape quality of hot-rolled strip steel, it is usually necessary to smooth the hot-rolled strip steel to improve the shape quality and surface of the strip steel. quality and mechanical properties.

For the traditional hot-rolled tempering unit and the leveling plus straightening unit, it is difficult to obtain the ideal target shape quality for hot-rolled high-strength steel ultra-high-strength steel and hot-rolled thin strip steel due to their limited comprehensive shape control capabilities, and the roller leveling The straight machine only plays a certain role in improving the shape of the thick gauge strip, but it is almost powerless to the thin gauge strip. In addition, for the traditional hot-rolled skin-passing line and the skin-passing and straightening line, it is necessary to wind the head of the strip to the coiler every time and establish tension before starting normal production, which will result in a long length of un-leveled strip , the shape quality and mechanical properties of the strip are poor, and the unleveled strip needs to be cut off in the subsequent use and downstream production process, resulting in a reduction in the yield.

Therefore, there is an urgent need for a process technology that can satisfy the finishing production of hot-rolled high-strength steel and hot-rolled strip steel and can improve the yield of products.

Contents of the invention

In view of this, the present invention provides a hot-rolled strip leveling and leveling process in order to solve the above-mentioned problems in the finishing process of the above-mentioned hot-rolled high-strength steel and hot-rolled thin strip steel, which can meet the requirements of hot-rolled high-strength steel and hot-rolled strip steel. The finishing production requirements of rolled thin strip can effectively eliminate plate shape defects, improve surface quality and mechanical properties, and can greatly increase the yield.

In order to achieve the above object, the present invention provides a hot-rolled strip leveling process, in which the hot-rolled strip passes through a roller leveler, a tempering machine, a first tension device, a tension leveler and a second tension device in sequence, and adopts The combination of straightening, leveling and tension leveling can eliminate the strip shape defects, improve the surface quality, improve the mechanical properties, reduce the residual stress level, and increase the composition rate of the unit; the tension device provides enough power for the tension leveler and the tempering machine tension, which is beneficial to strip threading and strip shape control, and improves the yield of finished products. The roll leveler can conduct preliminary strip shape control on hot-rolled strip steel. The flat shape defects can improve the mechanical properties of strip steel.

The beneficial effect of this basic scheme is that the roll leveler can form a certain amount of bending on the passing hot-rolled strip, so that the hot-rolled strip undergoes elastic-plastic deformation when passing through the roll leveler, so as to eliminate the hot-rolled Strip shape defects in the longitudinal and transverse directions; the tempering machine is used to level the hot-rolled strip after being straightened by the roller leveler, and because the surface of the hot-rolled strip passes through the roller leveler The iron oxide scale is prone to cracks and partial shedding. The rolling action of the temper mill can improve the surface quality of the hot-rolled strip; the first tension device provides sufficient front tension for the temper mill, so that the hot-rolled strip passes through the leveling process. After that, a straight plate shape can be obtained; under the action of the high tension of the two tension devices, the hot-rolled steel will undergo a certain plastic extension with a certain amount of reduction of the bending roll on the tension leveler, thereby effectively eliminating the strip shape. Defects, improve the surface quality of hot-rolled strip steel, improve its mechanical properties, reduce its residual stress level, and increase the rate of unit composition.

Further, both the first tensioning device and the second tensioning device include upper and lower sets of crawler-type driving chains, the driving chains are composed of several rectangular metal strips, which are in contact with the surface of the steel strip, wherein the upper driving chain can move in the horizontal direction and the vertical direction, It is convenient for belt threading, and the lower drive chain only moves in the horizontal direction, which plays a role in correcting the deviation of the strip steel. Beneficial effects: Both the first tension device and the second tension device adopt Umlauf tension device, which is a new type of tension device, which can provide a tension of up to 2000kN, which is more conducive to the smoothing machine and The tension leveler controls the shape of the strip steel. After the steel strip passes through the tempering machine, it enters the first tension device, and the tension can be quickly established and normal production can be carried out, thereby greatly reducing the length of the un-leveled steel strip and effectively improving the yield of the unit.

Further, an uncoiler is arranged in front of the roller straightener, and a coiler is arranged behind the second tension device; an inlet pinch roller is arranged between the uncoiler and the roller straightener, and a coiler is arranged between the second tension device and the coiler. Set the exit pinch roller between them. Beneficial effects: the entrance pinch roller plays the role of introducing the hot-rolled steel strip to be leveled, and the outlet pinch roller plays the role of leading out the hot-rolled strip steel after leveling, and can prevent the strip steel from running off to a certain extent.

Further, for hot-rolled steel strips with a thickness > 4 mm, the production method of roller straightening and leveling is adopted, that is, the hot-rolled steel strips pass through the roller leveler, the tempering machine, and the first tension device in sequence. At this time, the tension leveler and the second tension device are not put into use; for hot-rolled strip steel with a thickness ≤ 4mm, the production method of roller straightening, leveling and tension leveling is adopted, that is, the hot-rolled strip passes through the roller leveler, tempering machine, and the first A tension device, a tension leveler and a second tension device.

Further, the roller leveler adopts a five-roller or seven-roller straightening machine. The lower row of rollers of the roller leveler is fixed, and the upper row of rollers can move vertically, which is convenient for eliminating the shape defects of the strip. For strip rolling, the straightening machine is put into use in the whole process to cooperate with the tempering machine to control the shape of the strip; for hot-rolled strip steel with a thickness of ≤4mm, the straightening machine is only put into operation when the head and tail of the strip pass through , to improve the shape quality of the strip head and tail.

Furthermore, the tension leveling machine adopts the form of one bending and one leveling, two bending and one leveling or two bending and two leveling. For strip steel with tensile strength less than 500MPa and thickness ≥ 1mm, one bending and one leveling tensioning and leveling machine is used; For strip steel with tensile strength greater than 500MPa and thickness <1mm, use a tension leveler in the form of two bends and one straightening or two bends and two straightenings.

Further, encoders are installed on both the entrance pinch roll and the exit pinch roll for measuring the elongation of the strip. Beneficial effect: When the total elongation measured by the encoder does not match the set target value, the bending amount of the roller leveler, the rolling force of the tempering machine, the bending amount of the bending roll of the tension leveler and the front and rear Tension can be used to change the total elongation of the strip, and a reasonable elongation can effectively eliminate shape defects and improve mechanical properties.

The beneficial effects of the present invention are:

1. The hot-rolled strip steel leveling and leveling process disclosed in the present invention is aimed at the fact that the traditional hot-rolled skin-leveling unit and leveling plus leveling unit can not well meet the needs of hot-rolled high-strength steel and thin strip steel finishing production, and adopts leveling plus leveling The straightening method is used to process the thick strip steel, making full use of the strong ability of the roller straightening to control the shape of the thick strip steel; Thin-gauge strip steel is processed, using the ability of the straight head and tail of the roller leveler to improve the shape quality of the strip steel head and tail, and utilizing the strong shape control ability of stretching, bending and straightening for thin-gauge strip steel , the flatness is mainly used to regulate the shape, surface quality and mechanical properties of the hot-rolled strip.

2. The hot-rolled strip steel leveling and leveling process disclosed in the present invention adopts a combined process of straightening, leveling and stretching, which can meet the finishing production requirements of hot-rolled high-strength steel and thin strip steel, and can effectively eliminate the shape of the strip. defects, improve surface quality and enhance mechanical properties. Two sets of Umlauf tension devices are installed before and after the tension leveler to provide sufficient tension for the tension leveler and skin pass mill, which is beneficial to belt threading and control, and can greatly increase the yield of the unit.

Other advantages, objects and features of the present invention will be set forth in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the investigation and research below, or can be obtained from It is taught in the practice of the present invention. The objects and other advantages of the invention may be realized and attained by the following specification.

Description of drawings

In order to make the purpose of the present invention, technical solutions and advantages clearer, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

Fig. 1 is a schematic diagram of the unit structure of the hot-rolled strip leveling process of the present invention.

Reference signs: uncoiler 1, entrance pinch roll 2, roll leveler 3, skin pass machine 4, first tension device 5, tension leveler 6, second tension device 7, exit pinch roll 8, coil Take machine 9, hot-rolled steel strip 10.

Detailed ways

Embodiments of the present invention are described below through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation modes, and various modifications or changes can be made to the details in this specification based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the diagrams provided in the following embodiments are only schematically illustrating the basic concept of the present invention, and the following embodiments and the features in the embodiments can be combined with each other in the case of no conflict.

Wherein, the accompanying drawings are for illustrative purposes only, and represent only schematic diagrams, rather than physical drawings, and should not be construed as limiting the present invention; in order to better illustrate the embodiments of the present invention, some parts of the accompanying drawings may be omitted, Enlargement or reduction does not represent the size of the actual product; for those skilled in the art, it is understandable that certain known structures and their descriptions in the drawings may be omitted.

In the drawings of the embodiments of the present invention, the same or similar symbols correspond to the same or similar components; , "front", "rear" and other indicated orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred devices or elements must It has a specific orientation, is constructed and operated in a specific orientation, so the terms describing the positional relationship in the drawings are for illustrative purposes only, and should not be construed as limiting the present invention. For those of ordinary skill in the art, the understanding of the specific meaning of the above terms.

In the hot-rolled strip leveling process shown in Figure 1, after the hot-rolled strip 10 is uncoiled by the uncoiler 1, it passes through the entrance pinch roller 2, the roll leveler 3, and the tempering machine 4 sequentially from left to right. , the first tension device 5, the tension leveler 6, the second tension device 7, the outlet pinch roller 8, and coiled by the coiler 9 after the second tension device 7, to complete the whole finishing production process, thereby Get ideal shape quality, good surface quality and mechanical properties, and low residual stress levels.

The hot-rolled strip leveling process adopts a combination of straightening, leveling and tension leveling to eliminate strip shape defects, improve surface quality, improve mechanical properties, reduce residual stress levels, and increase machine composition rate; the tension device Provide enough tension for the tension leveler 6 and the tempering machine 4, which is beneficial to strip threading and strip shape regulation, and improves the yield. The tension leveler 6 can perform preliminary strip shape regulation on the hot-rolled strip 10. The tempering machine 4, tension The cooperative use of the device and the tension leveler 6 can eliminate the shape defects of the thin strip steel and improve the mechanical properties of the strip steel.

Wherein the roll leveler 3 can form a certain amount of bending to the passing hot-rolled strip 10, so that the hot-rolled strip 10 undergoes elastic-plastic deformation when passing through the roll leveler 3, so as to eliminate the hot-rolled strip 10. Plate shape defects in the longitudinal and transverse directions; the roller leveler 3 adopts a five-roller or seven-roller straightener, the lower row of rollers of the roller leveler 3 is fixed, and the upper row of rollers can move vertically, which is convenient for eliminating strip defects For plate shape defects, for hot-rolled strip steel 10 with a thickness > 4mm, the production method of roll straightening and leveling is adopted, that is, the hot-rolled strip steel 10 passes through the roll leveler 3, the tempering machine 4 and the first tension device in sequence 5. The first tension device 5 provides sufficient front tension for the tempering machine 4, so that the hot-rolled strip 10 can obtain a straight plate shape after leveling. At this time, the tension leveler 6 and the second tension device 7 do not Putting into use, the straightening machine is fully put into use to cooperate with the tempering machine 4 to control the shape of the strip; for the hot-rolled strip 10 with a thickness ≤ 4mm, the production method of roller straightening, leveling and stretching is adopted. That is, the hot-rolled strip steel 10 passes through the roll leveler 3, the tempering machine 4, the first tensioning device 5, the tension leveling machine 6 and the second tensioning device 7 in sequence, and fully utilizes the combination of the tempering machine 4 and the tensioning leveler 6 to Eliminate the shape defects of thin strip steel and improve the mechanical properties of the strip steel. The straightening machine is only used when the head and tail of the strip pass through to improve the shape quality of the head and tail of the strip steel.

The tempering machine 4 is used to level the hot-rolled strip 10 after being straightened by the roller leveler 3. At the same time, when the hot-rolled strip 10 passes through the roller leveler 3, the oxide scale on the surface is prone to cracks and cracks. Part falls off, and the rolling effect of tempering machine 4 can improve the surface quality of hot-rolled strip steel 10; For strip steel less than 500MPa and thickness ≥ 1mm, use one bending and one leveling tension leveling machine 6; for strip steel whose tensile strength is greater than 500MPa and thickness < 1mm, use two bending and one leveling or two bending and two leveling forms of tension leveling Machine 6. The hot-rolled steel strip 10 will undergo a certain plastic elongation under the action of the high tension of the two tension devices at the entrance and exit of the tension leveler 6, in conjunction with a certain amount of reduction of the bending rolls on the tension leveler 6, thereby effectively eliminating the tension of the strip steel. Shape defects improve the surface quality of the hot-rolled steel strip 10, improve its mechanical properties, reduce its residual stress level, and increase the rate of machine composition.

Both the first tensioning device 5 and the second tensioning device 7 include upper and lower two sets of crawler-type driving chains, the driving chains are made of several rectangular metal strips, which are in contact with the surface of the steel strip, wherein the upper driving chain can move in the horizontal direction and the vertical direction, It is convenient for belt threading, and the lower drive chain only moves in the horizontal direction, which plays a role in correcting the deviation of the strip steel. Both the first tension device 5 and the second tension device 7 use the Umlauf tension device, which is a new type of tension device, which can provide a tension of up to 2000kN, which is more conducive to the tempering machine 4 and The tension leveler 6 regulates the strip shape. After the steel strip passes through the tempering machine 4 and enters the first tension device 5, the tension can be quickly established and normal production can be carried out, thereby greatly reducing the length of the un-leveled steel strip and effectively improving the yield of the unit. The first tension device 5 provides sufficient front tension for the tempering machine 4, so that the hot-rolled steel strip 10 can obtain a straight plate shape after being leveled.

Both the entrance pinch roll 2 and the exit pinch roll 8 are equipped with encoders for measuring the elongation of the strip. When the total elongation measured by the encoder does not match the set target value, by adjusting the bending amount of the roller leveler 3, the rolling force of the tempering machine 4, the bending amount of the bending roll of the tension leveler 6 and the front and rear Tension can be used to change the total elongation of the strip, and a reasonable elongation can effectively eliminate shape defects and improve mechanical properties.

Finally, it is noted that the above embodiments are only used to illustrate the technical solutions of the present invention without limitation. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be carried out Modifications or equivalent replacements, without departing from the spirit and scope of the technical solution, should be included in the scope of the claims of the present invention.

Claims (7)

1. a kind of hot-strip leveling rectifys technique, which is characterized in that hot-strip passes sequentially through roll leveller, planisher, One tensioner, withdrawal straightening machine and the second tensioner eliminate strip using roll straightening, smooth and straightening combination Flatness defect improves surface quality, and elevating mechanism performance reduces residual stress level, improves unit lumber recovery；Wherein tension fills It is set to withdrawal straightening machine and planisher provides sufficiently large tension, be conducive to threading and plate shape regulates and controls, improve lumber recovery, roll straightening function Enough to carry out preliminary plate shape regulation to hot-strip, planisher, tensioner and being used cooperatively for withdrawal straightening machine can eliminate Thin Strip Steel Flatness defect, improve strip mechanical performance.

2. hot-strip leveling as described in claim 1 rectifys technique, which is characterized in that first tensioner and second Power device includes that two sets of caterpillar drive chains, drive chain are made of several rectangle metal strips, connect with belt steel surface up and down Touching is convenient for threading wherein upper drive chain can be moved both horizontally and vertically, and lower drive chain moves in only the horizontal direction It is dynamic, play the role of correction to strip.

3. hot-strip leveling as described in claim 1 rectifys technique, which is characterized in that uncoiling is arranged in front of roll leveller Coiling machine is arranged at the second tensioner rear in machine；The inlet porting pinch roller between uncoiler and roll leveller, second Setting outlet pinch roller between tensioner and coiling machine.

4. hot-strip leveling as described in claim 1 rectifys technique, which is characterized in that for the hot-strip of thickness G T.GT.GT 4mm, Using roll straightening plus smooth production method, i.e. hot-strip passes sequentially through roll leveller, planisher and the first tension dress It sets, withdrawal straightening machine and the second tensioner are not put at this time；For thickness≤4mm hot-strip, using roll straightening, it is smooth plus The production method of straightening, i.e. hot-strip pass sequentially through roll leveller, planisher, the first tensioner, withdrawal straightening machine and second Tensioner.

5. hot-strip leveling as described in claim 1 rectifys technique, which is characterized in that the roll leveller using five rollers or The lower roll of seven roller straighteners, roll leveller is fixed, and upper row's roller can vertically move, right convenient for eliminating the flatness defect of strip In the hot-strip of thickness G T.GT.GT 4mm, straightener whole process investment is matched with planisher, is controlled the plate shape of strip；For Thickness≤4mm hot-strip, straightener investment when the head of strip and tail portion pass through, improves strip head-tail plate form quality Amount.

6. hot-strip leveling as described in claim 1 rectifys technique, which is characterized in that the withdrawal straightening machine using one curved one rectify, Two curved one strong or two curved two strong forms, are less than 500MPa, thickness >=1mm strip for strip tensile strength, selection one is curved One strong withdrawal straightening machine；500MPa is greater than for strip tensile strength, the strip of thickness < 1mm selects two curved one to rectify or two curved two rectify The withdrawal straightening machine of form.

7. hot-strip leveling as claimed in claim 3 rectifys technique, which is characterized in that the entrance pinch roll and outlet pinch Encoder is mounted on roller, for measuring the elongation percentage of strip.