Control method for reducing sizing tension during small-specification wire rod production

Abstract

The invention relates to the technical field of high-speed wire rod rolling, in particular to a method for controlling reducing and sizing tension during production of small-specification wire rods, which comprises the following steps of: accurately dividing the size of incoming materials of a finishing mill and the size area of the incoming materials of reducing and sizing according to different specifications of wire rods with the diameter phi of 5.5-8mm and different steel types, and setting different static roll gaps of four reducing and sizing racks; and the diameter of the wire rod is phi 5.5 mm, and the speed ratios of four sorties in the reducing and sizing are 0.15718, 0.13618, 0.08513 and 0.08151 after optimization. According to different steel types, different reducing and sizing incoming material sizes are respectively formulated according to the characteristics of the steel types, and the purpose of reducing and sizing internal tension stability is achieved by adjusting the arrangement of roll gaps between racks in the reducing and sizing machine.

Description

Technical Field

[0001] The invention belongs to the technical field of high-speed wire rolling, and in particular relates to a method for controlling sizing tension during production of small-size wire rods. Background Art

[0002] The sizing mill unit consists of an AC motor driving two 230mm sizing mills and two 150mm sizing mills through a combined gearbox. The combined gearbox is equipped with 9 clutches. When rolling products of different specifications, the 9 clutch positions can be changed to combine the speed ratios that meet different process requirements. By setting a reasonable roll gap, it can ensure that the sizing mill unit is micro-tension rolling, thereby obtaining products with high dimensional accuracy. The maximum design speed of the sizing mill is 140m / s, and the guaranteed rolling speed is 112m / s.

[0003] During the rolling process of small-size wire rods, the rolling speed reaches 112m / s, the wire rods have low high-temperature strength in the range of 800-950℃ during the sizing reduction rolling process, the tension between the frames inside the sizing reduction unit is too large, and the tension between the frames fluctuates due to changes in the size and temperature of the incoming material, which will cause the instantaneous tension to be greater than the strength limit of the rolled piece, thereby causing the coil to break or shrink. The shrinkage and breaking will result in production losses and significant quality risks.

[0004] Chinese Patent CN116140352A: A control method to prevent the tail of small-sized wire from being left after sizing. This patent relates to the field of steel production technology, including: enlarging the design of the sizing roller gap to reduce the width of the material during rolling, so that the material is not easily squeezed into the roller gap; controlling the size of the incoming material; installing a water pipe at the second roller outlet guide in front of the finished sizing roller to flush the iron oxide scale in the next roller inlet guide: redesigning the hole type of the finished sizing roller, increasing the arc of the hole type, and increasing the size of the roller gap; controlling the stability of the rolled piece, and adjusting the tension during sizing to micro-tension control. Preventing the "tail" of small-sized production sizing, improving production smoothness, improving production efficiency, and reducing production costs. This patent is mainly for controlling the tail left after sizing, and does not involve controlling the size of incoming sizing materials for sizing by steel type, optimizing the sizing gear, etc., and cannot effectively solve the problem of breaking and shrinking caused by excessive internal tension in sizing.

[0005] Chinese Patent CN110052494A: A method for controlling the dimensional accuracy of wire rolling. The method involved in this patent includes the following steps: before rolling, determine the roller diameter difference, the roller diameter ratio of the sizing mill, the speed ratio difference of the sizing mill unit, the roller over-steel amount, the guide over-steel amount and the rolling temperature; start rolling, and control the mill vibration value, rolling elongation coefficient, clutch gear, clutch speed ratio and wire laying head advance coefficient during the rolling process. This method can solve the problem of unstable tension during the high-speed rolling process of the sizing mill unit, improve the rolling speed and product accuracy, but does not involve controlling the size of the sizing material according to the steel type, optimizing the sizing gear, etc., and cannot effectively solve the problem of breaking and shrinking caused by excessive internal tension in the sizing mill. Summary of the invention

[0006] The object of the present invention is to provide a method for controlling the sizing tension during the production of small-sized wire rods, so as to solve the problems raised in the above-mentioned background technology.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A method for controlling the tension of the reduced sizing during the production of small-sized wire rods. The wire rod diameter is φ5.5mm. For cold heading steel, welding steel, and free-cutting steel, the size requirement of the finishing mill incoming material is 17.0±0.2mm, and the area requirement of the reduced sizing incoming material is 37.1±0.3mm. 2 , the static roll gaps of the 4-frame reducing and sizing machine are set to 1.1-1.3mm, 1.12-1.14mm, 1.3-1.32mm, and 1.35-1.38mm respectively;

[0009] The wire rod diameter is φ5.5mm. For bead cord steel, bearing steel, spring steel, and tool steel, the size requirement for the finishing mill is 16.5±0.2mm, and the size area requirement for the reduced sizing material is 36.4±0.3mm. 2 , the static roll gaps of the 4-frame reducing and sizing machine are set to 0.9-1.1mm, 1.1-1.12mm, 1.3-1.32mm, and 1.35-1.38mm respectively;

[0010] The wire rod diameter is φ6.5-7mm. For cold heading steel, welding steel, and free-cutting steel, the size requirement for the finishing mill is 17.0±0.2mm, and the size area requirement for the reduced sizing material is 61.2±0.3mm. 2 , the static roll gaps of the 4-frame reducing and sizing machine are set to 1.1-1.3mm, 1.12-1.14mm, 1.3-1.32mm, and 1.35-1.38mm respectively;

[0011] The wire rod diameter is φ6.5-7mm. For bead cord steel, bearing steel, spring steel, and tool steel, the size requirement for the finishing mill is 16.5±0.2mm, and the size area requirement for the reduced sizing material is 60.5±0.3mm. 2 , the static roll gaps of the 4-frame reducing and sizing machine are set to 0.9-1.1mm, 1.1-1.12mm, 1.3-1.32mm, and 1.35-1.38mm respectively;

[0012] Wire rod diameter φ8mm specification, for cold heading steel, welding steel, free-cutting steel, the finishing mill incoming material size requirement is 17.0±0.2mm, and the reduced sizing incoming material size area requirement is 96.2±0.3mm 2 , the static roll gaps of the 4-frame reducing and sizing machine are set to 1.1-1.3mm, 1.12-1.14mm, 1.3-1.32mm, and 1.35-1.38mm respectively;

[0013] The wire rod diameter is φ8mm. For bead cord steel, bearing steel, spring steel, and tool steel, the size requirement for the finishing mill is 16.5±0.2mm, and the size area requirement for the reduced sizing material is 95.5±0.3mm. 2 The static roll gaps of the four reducing and sizing stands are set to 0.9-1.1mm, 1.1-1.12mm, 1.3-1.32mm, and 1.35-1.38mm respectively.

[0014] Preferably, for the wire rod with a diameter of φ5.5 mm, the speed ratios of the four reductions within the sizing range are optimized to be 0.15718, 0.13618, 0.08513, and 0.08151.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention realizes the control of reducing the internal tension of the sizing machine unit through the innovation of production process, and avoids the situation of wire rod breaking and shrinking; the present invention formulates different sizing incoming material sizes according to the characteristics of different steel grades, and then adjusts the roller gap settings between the frames inside the sizing machine to achieve the purpose of stabilizing the internal tension of the sizing machine; at the same time, the power transmission route in the sizing machine gearbox is modified in the electronic control program to optimize the speed ratio of each sizing machine and achieve the purpose of reducing the tension of each frame inside the sizing machine; it achieves the avoidance of wire rod breaking and shrinking during the production process, improves product quality, reduces production costs, and improves production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a morphology diagram of the breaking and shrinkage of the small-sized wire rod of the present invention. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

[0018] Embodiment 1:

[0019] The practical process of this new production process in a steel company for mass production of C82DA and C72DA steel for bead wire with a diameter of φ5.5mm is as follows:

[0020] (1) The steel company's tire bead wire production process: molten iron → 100-ton converter → LF refining furnace → 180*240 continuous casting machine → heating furnace → high-speed wire rolling → finished wire rod.

[0021] (2) The casting was carried out on the steel company's 6-machine 6-stream 180*240mm arc continuous casting machine, using light pressure reduction technology, with a reduction of 14mm, and the cross-sectional size of the qualified ingot was 166*240mm.

[0022] (3) The actual control of the incoming material size of the finishing mill (3# sheared semi-finished product) is controlled to 16.6±0.1mm.

[0023] (4) The actual controlled reduced sizing area is 36.5±0.2mm 2 .

[0024] (5) The roll gaps of each batch within the sizing reduction are set to 0.9-1.1mm, 1.1-1.12mm, 1.3-1.32mm, and 1.35-1.38mm.

[0025] (6) The speed ratios for each sizing reduction are 0.15718, 0.13618, 0.08513, and 0.08151.

[0026] Embodiment 2:

[0027] The practical process of this new production process in a steel company for batch production of welding steel ER50-6E with a diameter of φ5.5mm and cold heading steel SWRCH35K is as follows:

[0028] (1) The steel company's welding steel and cold heading steel production process: molten iron → 100-ton converter → LF refining furnace → 180*240 continuous casting machine → heating furnace → high-speed wire rolling → finished wire rod.

[0029] (2) The casting was carried out on the steel company's 6-machine 6-stream 180*240mm arc continuous casting machine, and the cross-sectional size of the qualified ingot was 180*240mm.

[0030] (3) The actual control of the incoming material size of the finishing mill (3# sheared semi-finished product) is controlled to 16.9±0.1mm.

[0031] (4) The actual controlled reduced sizing area is 36.9±0.2mm 2 .

[0032] (5) The roll gaps of each batch within the sizing reduction are set to 1.1-1.3mm, 1.12-1.14mm, 1.3-1.32mm, and 1.35-1.38mm.

[0033] (6) The speed ratios for each sizing reduction are 0.15718, 0.13618, 0.08513, and 0.08151.

[0034] Comparative Example 1:

[0035] The practical process of mass production of C82DA and C72DA steel for bead wire with a diameter of φ5.5mm using traditional technology is as follows:

[0036] (1) The production process is the same as that in Example 1.

[0037] (2) The actual control of the incoming material size of the finishing mill (3# sheared semi-finished product) is controlled to 16.9±0.1mm.

[0038] (3) The actual controlled reduced sizing area is 36.9±0.2mm 2 .

[0039] (4) The roll gaps of each batch within the sizing reduction are set to 1.1-1.3mm, 1.12-1.14mm, 1.3-1.32mm, and 1.35-1.38mm.

[0040] (5) The speed ratios for each sizing reduction are 0.15718, 0.13618, 0.08142, and 0.07780.

[0041] Comparative Example 2:

[0042] The practical process of mass production of welding steel ER50-6E with a diameter of φ5.5mm and cold heading steel SWRCH35K using traditional technology is as follows:

[0043] (1) The production process is the same as that in Example 2.

[0044] (2) The actual control of the incoming material size of the finishing mill (3# sheared semi-finished product) is controlled to 16.9±0.1mm.

[0045] (3) The actual controlled reduced sizing area is 36.9±0.2mm 2 .

[0046] (4) The roll gaps of each batch within the sizing reduction are set to 1.1-1.3mm, 1.12-1.14mm, 1.3-1.32mm, and 1.35-1.38mm.

[0047] (5) The speed ratios for each sizing reduction are 0.15718, 0.13618, 0.08142, and 0.07780.

[0048] Experimental results of embodiments and comparative examples:

[0049] The production processes of implementation case 1-2 and comparison case 1-2 were tracked, and the production data as well as the number of breakages and diameter reductions were collected. The results are listed in Table 1.

[0050] Table 1 Data collection results of breaking and reducing diameter

[0051]

[0052] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for controlling the sizing tension during the production of small-size wire rods, characterized in that: The wire rod diameter is φ5.5mm. For cold heading steel, welding steel, and free-cutting steel, the size requirement for the finishing mill is 17.0±0.2mm, and the size area requirement for the reduced sizing material is 37.1±0.3mm. 2 , the static roll gaps of the 4-frame reducing and sizing machine are set to 1.1-1.3mm, 1.12-1.14mm, 1.3-1.32mm, and 1.35-1.38mm respectively; The wire rod diameter is φ5.5mm. For bead cord steel, bearing steel, spring steel, and tool steel, the size requirement for the finishing mill is 16.5±0.2mm, and the size area requirement for the reduced sizing material is 36.4±0.3mm. 2 , the static roll gaps of the 4-frame reducing and sizing machine are set to 0.9-1.1mm, 1.1-1.12mm, 1.3-1.32mm, and 1.35-1.38mm respectively; The wire rod diameter is φ6.5-7mm. For cold heading steel, welding steel, and free-cutting steel, the size requirement for the finishing mill is 17.0±0.2mm, and the size area requirement for the reduced sizing material is 61.2±0.3mm. 2 , the static roll gaps of the 4-frame reducing and sizing machine are set to 1.1-1.3mm, 1.12-1.14mm, 1.3-1.32mm, and 1.35-1.38mm respectively; The wire rod diameter is φ6.5-7mm. For bead cord steel, bearing steel, spring steel, and tool steel, the size requirement for the finishing mill is 16.5±0.2mm, and the size area requirement for the reduced sizing material is 60.5±0.3mm. 2 , the static roll gaps of the 4-frame reducing and sizing machine are set to 0.9-1.1mm, 1.1-1.12mm, 1.3-1.32mm, and 1.35-1.38mm respectively; Wire rod diameter φ8mm specification, for cold heading steel, welding steel, free-cutting steel, the finishing mill incoming material size requirement is 17.0±0.2mm, and the reduced sizing incoming material size area requirement is 96.2±0.3mm 2 , the static roll gaps of the 4-frame reducing and sizing machine are set to 1.1-1.3mm, 1.12-1.14mm, 1.3-1.32mm, and 1.35-1.38mm respectively; The wire rod diameter is φ8mm. For bead cord steel, bearing steel, spring steel, and tool steel, the size requirement for the finishing mill is 16.5±0.2mm, and the size area requirement for the reduced sizing material is 95.5±0.3mm. 2 The static roll gaps of the four reducing and sizing stands are set to 0.9-1.1mm, 1.1-1.12mm, 1.3-1.32mm, and 1.35-1.38mm respectively.

2. The method for controlling the sizing tension during the production of small-size wire rods according to claim 1, characterized in that: For wire rods with a diameter of φ5.5mm, the speed ratios of the four reductions within the fixed diameter are optimized to 0.15718, 0.13618, 0.08513, and 0.08151.

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