A medium rolling method for producing Φ12mm hot-rolled ribbed steel bars by split rolling

Abstract

The present application provides a medium rolling method for producing Φ12mm hot-rolled ribbed steel bars by split rolling, wherein the medium rolling uses and only uses three rolling mills, which are No. 7, No. 8, and No. 9 in order of rolling, and No. 10 is an empty process; by changing to the flat material discharging process of the last stand No. 9 of the medium rolling, the No. 10 rolling mill is no longer used, and the power consumption per ton of steel is saved by 1.8KW / ton, and the cost per ton of steel is reduced by 1.17 yuan; the width expansion of the pre-finishing rolling No. 13 is 10mm larger than the same period last year, the pre-cut hole type is well filled, the line difference fluctuation is reduced to 3-8 meters, and the single negative difference fluctuation is controlled at about 0.5mm; the wear of the rolling groove of the No. 9 rolling mill is slowed down, and it is replaced every 3 days, which can be completed by 2 people in 30 minutes; the fullness of the pre-cut hole type and the cutting hole type is increased from 85% to 90%, and the two line differences are reduced from twice to once per shift, and the bundle weight difference is increased by 0.1%.

Description

Technical Field

[0001] The invention relates to the technical field of slitting and rolling production of threaded steel bars, in particular to a medium rolling method for slitting and rolling production of Φ12mm hot-rolled ribbed steel bars. Background Art

[0002] The high-bar production line of the rolling mill is designed to produce 1.5 million tons of high-quality rebar annually, and mainly produces high-quality rebar, while also producing low-alloy steel and high-quality carbon steel. The production line process has become stable, with a cumulative annual production capacity of about 1.5 million tons. The rolling of bar-shaped steel is to roll a steel billet through a rough rolling unit and an intermediate rolling method, and then cut the rolled piece into two or more parallel rolled pieces in the finishing rolling unit, which is called split rolling. The specific process is to first heat the steel billet, and then gradually roll it into shape through different rolling mills.

[0003] The existing rolling process has the following problems: 1). Due to the unreasonable hole design of the medium rolling mill, the service life of the hole slot is short and the material type adjustment and control are difficult; 2). The medium rolling of high-bar production with two specifications of Φ12 / 14mm uses No. 7-10 rolling mills, and the process power consumption of these four rolling mills is large; 3). The medium rolling presses more and the material is smaller, resulting in insufficient filling of the pre-finishing pre-cutting / cutting hole type, resulting in uneven wear of the rolling groove, line difference fluctuation of 5-10 meters, and a single negative difference fluctuation of 0.5-0.6mm, which makes it difficult to control the negative difference; 4). The No. 9 and No. 10 rolling mills are replaced every two days, and it takes 3 people 35 minutes to complete the roll change. Usually, there are 2 people in the roll change position who need to coordinate again, resulting in a large number of personnel occupation; 5). If one more rolling mill is used in the rolling line, one more rolling mill and guide and guard process parts spare parts need to be prepared, which increases the cost of process parts. Summary of the invention

[0004] The object of the present invention is to provide a medium rolling method for producing Φ12mm hot-rolled ribbed steel bars by slitting and rolling.

[0005] In order to solve the above technical problems, the technical solution proposed by the present invention is:

[0006] A medium rolling method for producing Φ12mm hot-rolled ribbed steel bars by slitting and rolling, wherein only three rolling mills are used for the medium rolling, which are No. 7 rolling mill, No. 8 rolling mill and No. 9 rolling mill in the order of rolling, and No. 10 rolling mill is used for empty passing.

[0007] Preferably, the structure and parameters of the pass of the No. 7 rolling mill are:

[0008] The roller gap height is 12mm and the hole bottom height is 43mm;

[0009] The maximum groove depth of the groove on the roller is 15.5 mm, and the radius of the arc-shaped cross section of the groove is 90 mm;

[0010] The horizontal width of the hole is 100.99 mm.

[0011] Preferably, the structure and parameters of the pass of No. 8 rolling mill are:

[0012] The hole pattern includes two tangential straight line segments and one arc segment, and the arc segment is located between the two tangential straight line segments;

[0013] The roll gap height is 10mm, the hole bottom height is 56mm, and the maximum groove depth of the groove on the roll is 23mm;

[0014] The radius of the arc segment is 28 mm, and the horizontal width of the hole is 58.89 mm;

[0015] The angle between the tangential straight line segment of the hole and the vertical line is 30°.

[0016] Preferably, the No. 9 rolling mill is a flat rolling mill.

[0017] Preferably, the intermediate rolling method is used for five-cut rolling of Φ12mm hot-rolled ribbed steel bars.

[0018] Preferably, the rolling line for five-section rolling of Φ12mm hot-rolled ribbed steel bars uses a total of 21 rolling mills, namely, 6 rough rolling mills, 3 intermediate rolling mills, 6 pre-finishing rolling mills, and 6 finishing rolling mills.

[0019] The present application has achieved the following beneficial technical effects:

[0020] 1). In this application, the intermediate rolling is changed to the intermediate rolling end stand No. 9 flat material process by modifying the hole type, and the No. 10 rolling mill is no longer used. The power consumption is reduced. According to the power consumption of the No. 10 motor, the power consumption per ton of steel is saved by 1.8KW / ton. According to the electricity price of 0.65 yuan / kW·h, the cost per ton of steel is reduced by 1.17 yuan, and a 1000KW motor is saved, with an annual income of 1.59 million.

[0021] 2). In this application, the flat material No. 9 is produced, and the width of the pre-finished rolling No. 13 is 10mm larger than the same period last year. The pre-cut hole type is well filled, the line difference fluctuation is reduced to 3-8 meters, and the single negative difference fluctuation is controlled at about 0.5mm, which provides favorable support for negative difference control.

[0022] 3). In this application, after using the No. 9 rolling mill flat roller, the groove wears slowly, and the No. 9 rolling mill roller is replaced every 3 days, which can be completed by 2 people in 30 minutes, thus achieving man-job matching.

[0023] 4). In this application, one rolling mill is used less, which reduces the process costs such as assembly, turning, and spare parts.

[0024] 5). In this application, the fullness of the pre-cutting hole type and the cutting hole type is increased from 85% to 90%, the difference between the two lines is reduced from two adjustments per shift to one, and the bundle weight difference is increased by 0.1%. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The structure, size and angle diagram of the pass type of the No. 7 rolling mill provided in Example 1 of the present application;

[0026] Figure 2 The structure, size and angle diagram of the pass type of the No. 8 rolling mill provided in Example 1 of the present application;

[0027] Figure 1-2 The dimensions are in mm. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described in combination with the embodiments of the present invention. Obviously, the described embodiments are 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 creative work belong to the scope of protection of the present invention.

[0029] The present application provides an intermediate rolling method for cutting and rolling to produce Φ12mm hot-rolled ribbed steel bars, wherein the intermediate rolling uses and only uses three rolling mills, which are rolling mill No. 7, rolling mill No. 8, and rolling mill No. 9 in order of rolling, and rolling mill No. 10 is subjected to empty-pass processing.

[0030] In one embodiment of the present application, the structure and parameters of the pass of the No. 7 rolling mill are:

[0031] The roll gap height is 12 mm, and the hole bottom height (the distance between the bottoms of the respective groove holes of the two rolls) is 43 mm;

[0032] The maximum groove depth of the groove on the roller is 15.5 mm, and the radius of the arc-shaped cross section of the groove is 90 mm;

[0033] The horizontal width of the hole is 100.99 mm.

[0034] In one embodiment of the present application, the structure and parameters of the pass of the No. 8 rolling mill are:

[0035] The hole pattern includes two tangential straight line segments and one arc segment, and the arc segment is located between the two tangential straight line segments;

[0036] The roll gap height is 10mm, the hole bottom height is 56mm, and the maximum groove depth of the groove on the roll is 23mm;

[0037] The radius of the arc segment is 28 mm, and the horizontal width of the hole is 58.89 mm;

[0038] The angle between the tangential straight line segment of the hole and the vertical line is 30°.

[0039] In one embodiment of the present application, the No. 9 rolling mill is a flat rolling mill.

[0040] In one embodiment of the present application, the intermediate rolling method is used for five-cut rolling of Φ12mm hot-rolled ribbed steel bars.

[0041] In one embodiment of the present application, a rolling line for five-section rolling of Φ12mm hot-rolled ribbed steel bars uses a total of 21 rolling mills, namely, 6 rough rolling mills, 3 intermediate rolling mills, 6 pre-finishing rolling mills, and 6 finishing rolling mills.

[0042] In this application, the width of the hole profile on both sides of the elliptical hole of the No. 7 rolling mill is increased, which can bear a larger deformation amount and ensure that the rolled piece will not have wings after filling the hole profile;

[0043] The hole type of the No. 8 rolling mill is a round hole type, which can ensure that the rolled piece will not be affected by the roll misalignment when entering the next pass, so that the deformation of the next pass is uniform;

[0044] The No. 9 rolling mill is a flat rolling roller, and the rolled piece can expand freely. When entering the box-type hole before pre-cutting, the hole filling degree is improved, and the shape and size on both sides of the rolled piece are more uniform, thereby reducing the deviation of the cross-sectional area of ​​the two lines after cutting.

[0045] In the present application, negative tolerance rolling means making the final rolled product thickness smaller than the target thickness, but the final rolled product thickness is within the negative tolerance range of the finished product. Negative tolerance rolling is beneficial to improving the yield rate, reducing the rolling cost, and does not impose additional requirements on the equipment. Negative tolerance rolling is a type of steel rolling process, in which the size of the rolled material is smaller than the nominal size, but within the nominal size tolerance range, and is a qualified product. Negative tolerance rolling has very strict process requirements. Once the size exceeds the tolerance, the scrap rate is very high, but good process control can improve productivity and economic benefits.

[0046] The methods and devices not described in detail in the present invention are all prior art and will not be described in detail.

[0047] In order to further understand the present invention, a medium rolling method for cutting and rolling Φ12mm hot-rolled ribbed steel bars provided by the present invention is described in detail below in conjunction with embodiments. The protection scope of the present invention is not limited by the following embodiments.

[0048] Example 1

[0049] A medium rolling method for producing Φ12mm hot-rolled ribbed steel bars by split rolling, wherein the medium rolling uses and only uses three rolling mills, which are No. 7 rolling mill, No. 8 rolling mill, and No. 9 rolling mill in the order of rolling, and No. 10 rolling mill is empty-passed (the steel bars are empty-passed through the No. 10 rolling mill, and the No. 10 rolling mill does not roll the steel bars);

[0050] The key dimensions and angles of the pass of the No. 7 rolling mill are as follows: Figure 1 As shown;

[0051] The key dimensions and angles of the pass of the No. 8 rolling mill are as follows: Figure 2 As shown;

[0052] Mill No. 9 is a flat roll mill;

[0053] The intermediate rolling method is used for five-cut rolling of Φ12mm hot-rolled ribbed steel bars;

[0054] The five-section rolling line for Φ12mm hot-rolled ribbed steel bars uses a total of 21 rolling mills, namely 6 rough rolling mills, 3 intermediate rolling mills, 6 pre-finishing rolling mills, and 6 finishing rolling mills.

[0055] The above embodiments are only used to help understand the method and core idea of ​​the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A medium rolling method for producing Φ12mm hot-rolled ribbed steel bars by split rolling, characterized in that: The intermediate rolling mill uses only three rolling mills, which are No. 7, No. 8, and No. 9 rolling mills in order of rolling. No. 10 rolling mill is used for empty processing. The structure and parameters of the pass of the No. 7 rolling mill are: The roller gap height is 12mm and the hole bottom height is 43mm; The maximum groove depth of the groove on the roller is 15.5 mm, and the radius of the arc-shaped cross section of the groove is 90 mm; The horizontal width of the hole is 100.99mm; The structure and parameters of the pass of the No. 8 rolling mill are: The hole pattern includes two tangential straight line segments and one arc segment, and the arc segment is located between the two tangential straight line segments; The roll gap height is 10mm, the hole bottom height is 56mm, and the maximum groove depth of the groove on the roll is 23mm; The radius of the arc segment is 28 mm, and the horizontal width of the hole is 58.89 mm; The angle between the tangential straight line segment of the hole and the vertical line is 30°; The No. 9 rolling mill is a flat rolling mill.

2. A medium rolling method for producing Φ12mm hot-rolled ribbed steel bars by splitting and rolling according to claim 1, characterized in that: The intermediate rolling method is used for five-cut rolling of Φ12mm hot-rolled ribbed steel bars.

3. The intermediate rolling method for producing Φ12mm hot-rolled ribbed steel bars by slitting and rolling according to claim 1, characterized in that: The five-section rolling line for Φ12mm hot-rolled ribbed steel bars uses a total of 21 rolling mills, namely 6 rough rolling mills, 3 intermediate rolling mills, 6 pre-finishing rolling mills, and 6 finishing rolling mills.

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