CN112792136A

CN112792136A - Multi-segmentation rolling variable-aperture segmentation roller, multi-segmentation rolling variable-aperture segmentation rolling mill and rolling process

Info

Publication number: CN112792136A
Application number: CN202110127150.9A
Authority: CN
Inventors: 张赵宁; 方实年; 蔡永朋; 罗华; 董祖伟; 潘天成; 何家宝
Original assignee: Huatian Engineering and Technology Corp MCC
Current assignee: Huatian Engineering and Technology Corp MCC
Priority date: 2021-01-29
Filing date: 2021-01-29
Publication date: 2021-05-14

Abstract

The invention discloses a multi-slitting rolling variable-aperture slitting roller, a multi-slitting rolling variable-aperture slitting rolling mill and a rolling process. The rollers comprise paired cutting rollers which are symmetrically arranged up and down; a plurality of cutting grooves are formed in the body of the cutting roller; the aperture of the cutting groove is gradually increased from outside to inside. The invention relates to a variable-aperture multi-segmentation rolling process, which is used for rolling bars by using the multi-segmentation rolling variable-aperture segmentation roller. Compared with the prior art, the multi-segmentation roller with the gradually-changed aperture segmentation groove realizes that the rolling piece at the edge part has 5-10% more rolling reduction than the rolling piece at the middle part in the segmentation rolling process through the aperture-changing segmentation rolling process, and the large rolling reduction causes large distortion in crystals, so that the temperature of the rolling material at the edge part is increased, the temperature loss caused by the temperature drop of the edge part of the rolling material with large flatness ratio is compensated, and the consistency and the stability of the mechanical properties of the edge and the middle of a finished bar are ensured.

Description

Multi-segmentation rolling variable-aperture segmentation roller, multi-segmentation rolling variable-aperture segmentation rolling mill and rolling process

Technical Field

The invention relates to the field of bar rolling, in particular to a bar slitting rolling process and a pass design. By means of the slotting design of the gradually changed aperture, the edge high-pressure rolling process of the bar during the splitting rolling can be realized, the temperature non-uniform distribution caused by the edge temperature drop during the rolling of the bar is eliminated, and the stability and the consistency of the mechanical properties of the bar after the splitting rolling are improved.

Background

The super-fine rod production line is mainly used for producing high-quality carbon steel, alloy structural steel, cold forging steel and other steel grades. In order to obtain high-quality and high-stability high-quality special bar products, advanced process technologies such as controlled rolling and controlled cooling, online heat treatment and the like are generally adopted during rolling to ensure the mechanical properties of the bars after rolling.

Meanwhile, in order to improve the production line efficiency of small-sized bars, a special roll pass and guide device or a splitting device with other structures is adopted in the rolling process to split one blank into more than two rolled pieces along the rolling direction. The bar slitting rolling can obviously improve the yield, and the current mainstream slitting rolling method comprises the following steps: the rolling method comprises four rolling methods, namely a roll cutting method, a slitting wheel slitting method, a disc slitting method, a flame slitting method and the like. The roll cutting method can realize the cutting rolling only by cutting a cutting groove on a roller, and can realize the single-cutting or multi-cutting rolling according to different passes, thereby being widely applied to various large steel mills.

When the roll cutting method is adopted for splitting rolling, blanks are firstly rolled into rectangular rolled pieces with large flatness ratio in the previous passes, the large flatness ratio can cause uneven temperature distribution of the rolled pieces in the width direction, specifically, the temperature of the edge of the rolled piece can be lower than that of the middle core part, so that the overall temperature of a split middle bar is higher than that of the edge bar, and the temperature difference of the middle bar after splitting rolling can influence the consistency and stability of the mechanical properties of the rolled bar.

In the plastic deformation stage of the metal, intragranular slippage and twin crystals, grain boundary slippage and diffusion creep deformation can be generated, and the distortion in the crystals can increase the internal energy of the crystals, so that the temperature of the metal is increased. The large reduction exhibited particularly in the rod rolling process results in large distortion in the crystal, so that the internal temperature of the rolled material rises.

In conclusion, based on the mechanism that the temperature in the rolled material is increased due to large rolling reduction, the multi-segmentation roller with the segmentation groove of the gradually-changed aperture is designed, the multi-segmentation rolling process with the aperture being changed is realized, the temperature difference between the edge and the middle of the rolled material with large flat ratio is reduced by increasing the rolling reduction of the edge bar during segmentation rolling, and the consistency and the stability of the mechanical property of the finished bar are improved.

Disclosure of Invention

Aiming at the problem that the consistency of the mechanical properties of the edges and the middle temperature of the finished product bars is affected due to the fact that the edge and the middle temperature of the bars are not uniformly distributed after being split by the conventional multi-splitting process for rolling the bars, the invention provides the multi-splitting roller with the splitting groove of the gradually-changed aperture, so that the multi-splitting rolling process with the variable aperture is realized, the difference of the edge and the middle temperature of the rolled bars with large flatness ratio is eliminated by increasing the reduction of the edge bars during splitting rolling, and the consistency and the stability of the mechanical properties of the finished product bars are improved.

In order to achieve the purpose, the multi-segmentation rolling variable-aperture segmentation roller comprises paired segmentation rollers which are symmetrically arranged up and down; a plurality of cutting grooves are formed in the body of the cutting roller; the aperture of the cutting groove is gradually increased from outside to inside.

Further, the inner aperture is 5% to 10% larger than the adjacent outer aperture.

Further, k5 and k3 are oval pre-cut hole patterns, and k2 is a circular cut hole pattern.

Furthermore, the cutting groove has two structural forms of four cutting and five cutting.

In order to achieve the purpose, the multi-splitting rolling variable-aperture splitting rolling mill is provided with the multi-splitting rolling variable-aperture splitting roller.

In order to achieve the purpose, the variable-aperture multi-splitting rolling process of the invention rolls bars by using the variable-aperture multi-splitting rolling dividing roller.

Compared with the prior art, the multi-segmentation roller with the gradually-changed aperture segmentation groove realizes that the rolling piece at the edge part has 5-10% more rolling reduction than the rolling piece at the middle part in the segmentation rolling process through the aperture-changing segmentation rolling process, and the large rolling reduction causes large distortion in crystals, so that the temperature of the rolling material at the edge part is increased, the temperature loss caused by the temperature drop of the edge part of the rolling material with large flatness ratio is compensated, and the consistency and the stability of the mechanical properties of the edge and the middle of a finished bar are ensured.

Drawings

FIG. 1 schematic diagram of roll grooving in four-slitting rolling

FIG. 2 is a schematic view of roll grooving in the case of five-segment rolling

FIG. 3 hole pattern of four-slit rolling

FIG. 4 hole pattern of five-segment rolling

In FIG. 1, 1-1 and 1-4 are roll necks, 1-2 are dividing grooves, 1-3 are roll bodies, and 1-5 are driving ends; in FIG. 2, 2-1 and 2-4 are roll necks, 2-2 are cutting grooves, 2-3 are roll bodies, and 2-5 are driving ends; in FIG. 3, 3-1 is the k5 pass during the quarter-cutting, 3-2 is the k3 pass during the quarter-cutting, and 3-3 is the k2 pass during the quarter-cutting; in FIG. 4, 4-1 is the k5 pass for five cuts, 4-2 is the k3 pass for five cuts, and 4-3 is the k2 pass for five cuts.

Detailed Description

The invention is described in further detail below with reference to the following figures and specific embodiments:

for a rolling production line of high-strength steel high-quality special bars, a rolling line arrangement of 24 racks is generally adopted, wherein 6 frames of a rough rolling unit, 6 frames of a middle rolling unit, 4 frames of a pre-finishing rolling unit, 4 frames of a finishing rolling unit and 4 frames of a reducing sizing mill unit are adopted, and the number of the pre-finishing rolling unit, the number of the finishing rolling unit and the number of the reducing sizing mill unit can be flexibly adjusted according to different specifications of finished products. During slitting rolling, slitting rolling of the bar can be realized through three-pass slitting, wherein 2-pass pre-slitting rolling and 1-pass slitting rolling are adopted.

As shown in fig. 1 and 2, a cutting groove is formed in the roll body of the cutting roll, and according to the technological requirements of cutting rolling, two structural forms of four-cutting and five-cutting can be respectively formed. The cutting grooves in the upper and lower arranged cutting rollers can be mutually spliced into a complete cutting groove (figures 3 and 4), and the inner diameter of the roller cutting groove is matched with the diameter of a rolled piece for cutting and rolling. As shown in fig. 3 and 4, in the cutting grooves of the same pass, since the radius of the edge cutting grooves is smaller than that of the middle cutting grooves, the rolling reduction of 5-10% more can be brought to the edge rolled piece in the rolling process.

In this embodiment, the deformed steel bars and the round steel bars of Φ 10, Φ 12, and Φ 14 may be subjected to four-division rolling, and the deformed steel bars and the round steel bars of Φ 8, Φ 10, and Φ 12 may be subjected to five-division rolling. Rolling into a dumbbell-shaped rolled piece through the oval pre-splitting holes of k5 and k3, and then completing splitting rolling through the circular splitting holes of k2 passes.

The multi-segmentation roller adopted in the embodiment has the segmentation grooves with gradually changed apertures, and the segmentation rolling process with the changed apertures ensures that the rolling piece at the edge part has 5 to 10 percent more rolling reduction than the rolling piece at the middle part in the segmentation rolling process, so that larger distortion occurs in crystals of the rolled material at the edge part, the temperature loss of the rolled material with large flatness ratio due to the temperature drop at the edge part is compensated, and the consistency and the stability of the mechanical properties of the edge and the middle of the finished bar are ensured.

The invention has been described above with reference to the accompanying drawings, it is obvious that the invention is not limited to the specific implementation in the above-described manner, and it is within the scope of the invention to apply the inventive concept and solution to other applications without substantial modification.

Claims

1. The variable-aperture multi-splitting rolling splitting roller is characterized by comprising paired splitting rollers which are symmetrically arranged up and down; a plurality of cutting grooves are formed in the body of the cutting roller; the aperture of the cutting groove is gradually increased from outside to inside.

2. The multi-slit rolling variable aperture slitting roll according to claim 1, wherein the inner aperture is 5% to 10% larger than the adjacent outer aperture.

3. The multi-slit rolling variable-aperture slitting roller according to claim 1, wherein k5 and k3 are oval pre-slit slits and k2 is a circular slit.

4. A multi-slit rolling variable aperture slitting mill, characterized in that the multi-slit rolling variable aperture slitting mill of claim 1 is provided thereon.

5. A variable-aperture multi-slit rolling process for rolling a bar using the variable-aperture slitting roller of claim 1.