Method for rolling deformed steel bar with specification of phi 12mm through four-segmentation hole pattern

Abstract

The invention discloses a method for rolling deformed steel bars with the specification of phi 12 mm through a four-segmentation hole pattern, belongs to the technical field of steel rolling segmentation rolling, and solves the problem that in existing deformed steel bar production, in the four-segmentation rolling process, a punching opening of a finished product rack breaks down frequently. The method comprises the following steps that inlet guides and outlet guides of all racks of all production units are installed and aligned, the opening degree of the guides is adjusted, the sizes of rolled pieces are matched, deformed steel bars are rolled into phi 71 mm round holes in 1 #-6 # roughing rolling units, the deformed steel bars enter 7 #-11 # intermediate rolling units and 13 #-18 # finishing rolling units to be rolled in sequence, the deformed steel bars are divided through a 16 # rolling mill, shaped through a 17 # rolling mill and a 18 # rolling mill, and finished products are output. According to the method, the hole pattern design and the rolling mill splitting hole pattern design in the intermediate rolling mill unit are changed, and the height of the flat material pattern is controlled, so that the bending deformation of the head of the rolled piece is basically eliminated, and the bending punching opening fault caused by head deflection is completely eradicated.

Description

Technical Field

[0001] The invention belongs to the technical field of steel rolling and splitting, and in particular relates to a method for rolling Φ12mm threaded steel with a four-split hole profile. Background Art

[0002] Rebar manufacturers generally use four-cut rolling to produce small-sized products to significantly improve product quality and reduce production costs. However, the four-cut rolling process requires high precision in material shape control and is difficult to adjust for each rack. The most common fault is the finished product rack rushing out of the outlet, which seriously affects the further improvement of the four-cut output and the improvement of indicators.

[0003] In current production, the cross-sectional area of ​​the rolled product of the 12# rolling mill of the intermediate rolling mill is elliptical. The ends of the rolled product are flush after the 2# flying shear head. During the deformation process of the 13# rolling mill flat roll, the middle part of the rolled product is pressed down more than the two sides, and the middle part of the rolled product extends more than the two sides. In addition, the rolled products of the first four stands of the finishing mill (13#-16# rolling mills) are relatively wide, and the deformation mechanisms of the two center lines and the two side lines in the pre-cut hole profile and the cutting hole profile are different. The metal of the two middle lines mainly extends in the length direction due to the constraints of the pre-cut hole profile and the cutting hole profile, and the metal of the two side lines extends in the length direction at the same time. When the rolled piece is deformed by the 17# mill, the head deflection is more obvious. When the rolled piece with a deflected head enters the pass of the 18# mill, the pointed part contacts the roller first. After the pointed part is deformed by rolling, a bend defect is bound to occur. Once the head is severely bent, it is very easy to touch the tip of the exit guide nose cone and cause bending, which will eventually cause the finished product rack to rush out of the exit. Summary of the invention

[0004] The invention provides a method for rolling Φ12mm threaded steel with a four-section pass, so as to solve the problem of frequent failure of the finished product frame outlet during the four-section rolling process in the current threaded steel production.

[0005] The technical solution of the present invention is: a method for rolling Φ12mm threaded steel with a four-section groove, comprising the following steps: A. Align the inlet and outlet guides of each production unit and each frame, and adjust the opening of the guides to match the size of the rolled piece; B. The rebar is rolled into a Φ71mm round hole in the 1#-6# rough rolling mill and enters the intermediate rolling mill unit along the production line; C. The rebar is rolled in the 7#-11# intermediate rolling mills in sequence, among which the 7# rolling mill adopts an elliptical hole type, the 8# rolling mill adopts a round hole type, the 9# rolling mill adopts a flat roll rolling, the 10# rolling mill adopts a box-type hole type, and the 11# rolling mill adopts a flat roll rolling. After the intermediate rolling mill is finished, the rebar enters the finishing mill along the production line; D. Rebar is rolled in the 13#-18# finishing mills in sequence, among which the 13# mill is flat roll rolling, the 14# mill is box-type, the 15# mill is pre-slitting hole type, the 16# mill is slitting hole type, and the 17# and 18# mills are shaped and output as finished products.

[0006] As a further improvement of the present invention, in step C, the flat rolled piece (26mm×61mm) produced by the 11# rolling mill passes horizontally through the 2# flying shear, and the cross-section of the head after the 2# flying shear is rectangular and the end faces of the head are flush. After passing through the 2# flying shear, it enters the finishing mill for rolling.

[0007] As a further improvement of the present invention, in step D, the actual height of the rolled piece passing through the 13# rolling mill is no more than 17.5 mm.

[0008] As a further improvement of the present invention, in step E, the gap between the cutting blades of the 16# rolling mill hole is 0.84 mm. When the rolls of this batch are grooved, roller rings with a height of 1 mm need to be left on both sides of the hole to prevent the cutting blades from touching and falling off during the operation of the rolls.

[0009] As a further improvement of the present invention, a looper is installed between the finishing mill stands to realize tension-free rolling, and the number of looper channels is consistent with the number of rolled pieces.

[0010] The beneficial effects of the present invention are as follows: by changing the hole design in the intermediate rolling mill group, the hole type of the 9# rolling mill is adjusted from an ellipse to a flat roll, the hole type of the 10# rolling mill is adjusted from a circle to a box type, and the hole type of the 11# rolling mill is adjusted from an ellipse to a flat roll, so that the flat rolled piece produced by the 11# rolling mill is flush with the end of the rolled piece after being cut by the 2# flying shear, and the cross-sectional area of ​​the rolled piece is close to a rectangle. When the rolled piece is rolled and deformed in the finishing mill group, the pressing amount in the width direction of the rolled piece is consistent, and the extension is basically consistent, so there is no obvious bulging and deformation at the head of the rolled piece. At the same time, the height of the rolled piece is controlled by the 13# rolling mill, and the height is adjusted from the original unlimited height to the current actual height of the rolled piece not greater than 17.5mm, so that the pressing amount of the threaded steel in the pre-cutting hole type of the 15# rolling mill and the cutting hole type of the 16# rolling mill is small, and the heads of the 4-line rolled pieces are relatively standardized after the four-piece rolled piece is separated, and the upper and lower rolling grooves are basically in contact with the head of the rolled piece when the finished product frame bites in, and the bending deformation of the head of the rolled piece is basically eliminated, and the bending outlet failure caused by the deflection of the head is eliminated. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a schematic diagram of the pass type of the 8#-11# rolling mill of the present invention; Figure 2 This is a schematic diagram of the pass type of the 13#-18# rolling mill of the finishing mill group of the present invention; Figure 3 It is a schematic diagram of the cross-section and head shape of each batch of rolled products corresponding to the original four-section rolling hole system of Φ12mm threaded steel; Figure 4 Schematic diagram of the cross section and head shape of the rolled piece corresponding to the pass system of the present invention; Figure 5 This is the cutting hole diagram of the 16# rolling mill in the embodiment of the present invention. DETAILED DESCRIPTION

[0012] The present invention is further described in detail below in conjunction with specific implementation modes.

[0013] Embodiment 1: Application example of the method of rolling Φ12mm rebar through a four-section groove of the present invention: A method for rolling Φ12mm threaded steel bars with a four-section pass, wherein the rough rolling mill performs 6 passes, the pass system is an elliptical-circular common pass system, the size of the rolled piece output by the 6# rolling mill is a Φ71mm circle, the intermediate rolling mill performs 5 passes (the 12# rolling mill uses a guide groove for empty passage), the 7# rolling mill has an elliptical pass; the 8# rolling mill has a circular pass, the size of the rolled piece of the 8# frame is a Φ55mm circle; the 9# rolling mill is flat roll rolling, the roll gap value of which is set to 29mm; the 10# rolling mill is a box-type pass, the roll gap value of which is set to 22mm, the size of the rolled piece is a 60×30mm rectangular rolled piece; the 11# rolling mill is flat roll rolling, the roll gap value of which is set to 26mm, and the shape of the rolled piece is a flat rolled piece.

[0014] The flat rolled products are transported along the production line and enter the 12# rolling mill from the intermediate rolling mill. After the 12# rolling mill has empty rolls, it enters the finishing rolling mill.

[0015] The finishing mill group rolled 6 passes, among which the 13# mill was flat roll rolling. Since the actual height of the rolled piece was 17.3mm, the roll gap value was set to 17.5mm. The 14# mill was a box-type hole, the roll gap setting value was 8mm, and the rolled piece was rectangular; the 15# mill was a pre-cut hole type, the height of its two center lines was 16.52mm, the height of its side lines was 16mm, the roll gap setting value was 2.6mm, and the rolled piece was a four-line parallel rolled piece; the 16# mill was a cutting hole type, the height of its two center lines was 13.8mm, the height of its two side lines was 14.3mm, and there were straight line segments at the bottom of the two center line holes, and the cutting blade gap was 0.84mm; the 17# mill was an elliptical hole type, the roll gap setting value was 2.7mm, and the rolled piece of this run was elliptical; the 18# mill was a finished hole type.

[0016] Through the hole type optimization design of the intermediate rolling unit 7#-11# rolling mills and the finishing rolling unit 13#-18# rolling mills, the deformation mechanism is analyzed and studied to reduce the uneven deformation of the heads of the rolled pieces in the finishing rolling unit 13#-18# rolling mills, ensure that the heads of the rolled pieces are relatively flat before cutting, and the heads of each line are standardized after cutting, and the head shape is improved, so that there is no problem of elbowing and breaking the nose cone when the finished product frame bites in, effectively solving the problem of the four-cut rolling outlet failure of this specification.

[0017] The process parameter design is shown in the table below: The flat rolled pieces of the 11# rolling mill are horizontally cut by the 2# flying shear. The heads of the rolled pieces are flush after cutting. Each group of rolling grooves of the 17# and 18# rolling mills corresponds to 4 rolling grooves with equal spacing (the spacing is generally 135mm), which are used to roll the 4-line rolled pieces separated by the 16# rolling mill at the same time. The outlet of the 17# rolling mill is equipped with a torsion guide, and the 4-line rolled pieces are twisted 90° and enter the 18# rolling mill to be rolled into finished products.

[0018] The hole design of each batch (except flat rolls) is combined with the inlet and outlet guide configurations and the roll body length to design the hole matching roll diagram. The rolls are grooved and assembled according to the matching roll diagram before being put into use.

[0019] In order to stabilize the size control of the rolled product and reduce the changes in the size of the rolled product on each stand caused by the wear of the rolling groove during the production process, the finishing mill uses high-speed steel rollers for the finished product stand, the pre-finished product stand, and the pre-cutting stand.

Claims

1. A method for rolling Φ12mm threaded steel with a four-section groove, characterized in that: The steps include: A. Align the inlet and outlet guides of each production unit and each frame, and adjust the opening of the guides to match the size of the rolled piece; B. The rebar is rolled into a Φ71mm round hole in the 1#-6# rough rolling mill and enters the intermediate rolling mill along the production line; C. The rebar is rolled in the 7#-11# intermediate rolling mills in sequence, among which the 7# rolling mill adopts an elliptical hole type, the 8# rolling mill adopts a round hole type, the 9# rolling mill adopts a flat roll rolling, the 10# rolling mill adopts a box-type hole type, and the 11# rolling mill adopts a flat roll rolling. After the intermediate rolling mill is finished, the rebar enters the finishing mill along the production line; D. Rebar is rolled in the 13#-18# finishing mills in sequence, among which the 13# mill is flat roll rolling, the 14# mill is box-type, the 15# mill is pre-slitting hole type, the 16# mill is slitting hole type, and the 17# and 18# mills are shaped and output as finished products.

2. The method for rolling Φ12mm threaded steel bars with a four-section groove according to claim 1, characterized in that: In the step C, the flat rolled piece from the 11# rolling mill passes horizontally through the 2# flying shear, and the end surface of the head of the 2# flying shear is flush after the 2# flying shear head, and then enters the finishing mill group for rolling after passing through the 2# flying shear head.

3. The method for rolling Φ12mm threaded steel with a four-section groove according to claim 1, characterized in that: In the step D, the actual height of the rolled piece passing through the 13# rolling mill is no more than 17.5 mm.

4. The method for rolling Φ12mm threaded steel bars with a four-section groove according to claim 1, characterized in that: In the step E, the gap between the cutting blades of the 16# rolling mill pass is 0.84 mm, and when the rolls of this batch are grooved, roller rings with a height of 1 mm need to be left on both sides of the pass.

5. A method for rolling Φ12mm threaded steel with a four-section groove according to any one of claims 1 to 4, characterized in that: Loopers are installed between the finishing mill frames, and the number of looper channels is consistent with the number of rolled pieces.

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