Method for setting new-specification roll gap for high-speed wire rod rolling mill and application

Abstract

The invention discloses a method for setting a new-specification roll gap of a high-speed wire rod mill and application, comprising the steps of setting roll gaps at an inlet / outlet of a straightening machine and setting 20-pass parameters of the high-speed wire rod mill, setting a reference seam as an initial roll gap by using the roll gaps at the inlet / outlet of the straightening machine, and setting a roll gap at the tail end of the 20-pass roll gap as a target roll gap. The roll gap adjusting hydraulic cylinder lifting stroke corresponding to the target roll gap of each pair of rollers is calculated according to the initial roll gap and the target roll gap, the high-speed wire rod rolling mills comprise the first roughing mill and the second roughing mill, the third intermediate rolling mill to the eighteenth intermediate rolling mill, the two passes of finishing mills are selected, the 19 finishing mills and the 20 finishing mills are selected, and the rest are the idle passes; and according to the actual square billet and the product specification and size, the total extension coefficient is determined and reasonably distributed to each pass.

Description

Technical Field

[0001] The invention belongs to the technical field of high-speed wire production in the metallurgical industry, and specifically relates to a method for setting a new specification of roll gap for a high-speed wire rolling mill and an application thereof. Background Art

[0002] With the rapid development of my country's national economy, the wire metal products industry has made certain progress in both production capacity and products. At the same time, more requirements have been put forward for the raw materials needed by the industry, mainly manifested in: 1. In order to be more economical and convenient, the demand for non-standard specifications of wire rods has increased. 2. The single coil weight of wire rods is expected to be improved on the current basis. 3. The demand for high-quality steel and alloy steel has increased significantly. Morgan's fifth-generation high-speed wire rod mill is the mainstream rolling mill model for domestic wire rod production. Its design product outline is finished smooth wire rods with a diameter of ф5.5mm-ф20mm and an increment of 0.5mm. In order to meet the downstream metal product companies' demand for the advancement of wire rod deep processing technology and the expansion of deep processing products, the market has a large demand for non-standard wire rods with a diameter of Φ17.3mm. However, many high-speed wire rod mills cannot produce wire rods with a diameter of Φ17.3mm due to the limitations of equipment level and process design. In order to meet the personalized needs of users, new designs with a diameter of Φ17.3mm are needed for production, which can not only broaden the product outline, but also reserve technical capabilities. The hole design of each batch of Φ17.3mm specifications of high-speed wire rod mills is a key link. Whether the design is reasonable directly affects the quality of the final product and the stability of the production process.

[0003] In view of the above factors, a method and application of setting a new specification of roll gap for a high-speed wire rod rolling mill is provided. The process of producing Φ17.3mm round steel using a high-speed wire rod rolling mill is stable, steel piling accidents are reduced, and the utilization rate and hourly output of the rolling mill are improved. This method has practical promotion value for domestic enterprises using high-speed wire rod rolling mills. Summary of the invention

[0004] The object of the present invention is to provide a method and application for setting a new specification of roll gap for a high-speed wire rolling mill, so as to solve the problems raised in the above-mentioned background technology.

[0005] The object of the present invention is achieved through the following technical scheme: a method for setting a new specification roll gap of a high-speed wire rod rolling mill, including roll gap setting at the inlet / outlet of a straightener and 20-pass parameter setting of the high-speed wire rod rolling mill, taking the reference gap of the roll gap setting at the inlet / outlet of the straightener as the initial roll gap, taking the end roll gap of the 20-pass roll gap as the target roll gap, and calculating the roll gap adjustment hydraulic cylinder lifting stroke corresponding to the target roll gap of each pair of rollers through the initial roll gap and the target roll gap;

[0006] The high-speed wire rod mill includes roughing, intermediate rolling and pre-finishing rolling for a total of 20 times, of which the roughing mills are the 1st and 2nd stands, the intermediate rolling mills are the 3rd to 18th stands, the finishing mill is selected for 2 passes, and the finishing mills are selected for the 19th and 20th stands, and the rest are empty passes;

[0007] According to the actual billet and product specifications, the total elongation coefficient is determined and reasonably allocated to each pass.

[0008] Further, the roller gap setting at the inlet / outlet of the straightening machine includes a straightening machine with an even number of frames, wherein the 4-roller structure is the main one, and the roller gap setting at the inlet of the straightening machine ensures that the reverse bending rate of roller 2 is 1 / P 2 =1 / P S , the residual curvature of the blank after the second reverse bending is zero;

[0009] When the blank passes through the third roller, the total reverse curvature can be controlled within the range of 1 / Pw-1.222 / Pw, and the residual curvature is in the same direction as the reverse curvature of the second roller;

[0010] The setting of the roll gap of the 4th roll ensures that the reverse curvature of the strip produced by the straightening force B of the 3rd roll satisfies that the reverse curvature is less than the minimum value of the elastic-plastic bending curvature, i.e., 1 / P 3 <1 / P w ;

[0011] Among them, 1 / Pw is the minimum value of elastic-plastic bending complex curvature, 1 / Pw=2Re / Eh, Re is the yield stress of the strip, h is the thickness of the strip, and E is the elastic modulus of the strip.

[0012] Furthermore, after the roll gap at the inlet / outlet of the straightening machine is set, the straightening machine is used for straightening and then the wire rod enters the high-speed wire rolling mill for 20 passes for rolling;

[0013] The high-speed wire rod rolling mill selects 20 rolling passes according to the maximum pass elongation coefficient allowed by the elliptical-circular hole type system and the motor capacity of the rolling mill, and reasonably allocates the elongation coefficient of each pass according to the total elongation coefficient of the billet and the 20 rolling passes;

[0014] The setting of the total elongation coefficient of the billet in 20 passes of the high-speed wire rod rolling mill should be redistributed before entering the high-speed wire rod rolling mill after the roll gap is set at the inlet / outlet of the straightening machine.

[0015] Furthermore, the first to 20th passes of the high-speed wire rod rolling mill are based on 150 2 The billet and product specifications are Φ17.3mm, and the total elongation coefficient is determined to be 95.76;

[0016] Among them, the elongation coefficient of the first pass is 1.296, and the roll gap is set to 19.5. The elongation coefficient of the 20th pass is 1.075, and the roll gap is set to 1.0.

[0017] Furthermore, according to 150 2 The cross-sectional area of ​​the billet from 1st to 20th pass and the elongation coefficient of 20 passes are used to determine the cross-sectional area of ​​the billet and product specifications of Φ17.3mm and the cross-sectional area of ​​the billet from 1st to 20th pass and the hole parameters and roll gap value from 1st to 20th pass.

[0018] Furthermore, the parameters of each pass of the Φ17.3mm round steel formed from the 1st pass to the 20th pass are as follows:

[0019]

[0020]

[0021] Furthermore, the high-speed wire rod mill finishing mill adopts a single-motor collective transmission, and adjacent frames are vertically intersected at +45° / -45° and +75° / -15°. Different transmission ratios are formed between adjacent frames through speed increasers, cone boxes, and roller boxes. The transmission ratio is fixed, and the speed ratio between two adjacent frames is fixed. The cross-sectional area of ​​the rolled pieces from the 1st to the 20th passes and the fixed transmission ratio ensure that the two adjacent frames in the 19th to the 20th pass group are micro-tension rolling.

[0022] Furthermore, the ellipse-circle-ellipse-circle... hole type system is used inside the 19th to 20th passes. The cross-sectional area, i.e., height x width, of the incoming rolled piece entering the 19th to 20th passes is first determined according to the rolling specifications and the rotation speed and transmission ratio of the 19th to 20th passes.

[0023] A method for setting a new specification of roll gap for a high-speed wire rolling mill is applied to the field of high-speed wire production in the metallurgical industry.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The present invention designs a method for setting a new specification of roll gap for a high-speed wire mill, especially a roll gap setting method for high-speed wire mills producing Φ17.3mm round steel, which ensures stable production process of Φ17.3mm round steel, reduces steel pile accidents, improves mill utilization and mill hourly output, and product size accuracy meets user requirements. According to the annual production of Φ17.3mm round steel products, 1,000 tons, each ton of profit is 100 yuan, so the direct economic benefit is about 1000X100=10 (million yuan) per year. For domestic high-speed wire enterprises of the same type, the invention has a good promotion and application value. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0027] A method for setting a new roll gap of a high-speed wire rod mill includes roll gap setting at an inlet / outlet of a straightener and 20-pass parameter setting of the high-speed wire rod mill, wherein the reference roll gap setting at the inlet / outlet of the straightener is used as the initial roll gap, the end roll gap of the 20-pass roll gap is set as the target roll gap, and the roll gap adjustment hydraulic cylinder lifting stroke corresponding to the target roll gap of each pair of rollers is calculated through the initial roll gap and the target roll gap;

[0028] The high-speed wire rod mill includes roughing, intermediate rolling and pre-finishing rolling for a total of 20 times, of which the roughing mills are the 1st and 2nd stands, the intermediate rolling mills are the 3rd to 18th stands, the finishing mill is selected for 2 passes, and the finishing mills are selected for the 19th and 20th stands, and the rest are empty passes;

[0029] According to the actual billet and product specifications, the total elongation coefficient is determined and reasonably allocated to each pass.

[0030] By setting a straightening machine at the entrance of the high-speed wire rod rolling mill, the billet enters the high-speed wire rod rolling mill for 20 passes of rolling to form a standard product after the roll gap is set at the entrance / exit of the straightening machine.

[0031] The roller gap setting at the inlet / outlet of the straightening machine includes a straightening machine with an even number of frames, wherein the 4-roller structure is the main one, and the roller gap setting at the inlet of the straightening machine ensures that the reverse bending rate of roller 2 is 1 / P 2 =1 / P S , the residual curvature of the blank after the second reverse bending is zero;

[0032] When the blank passes through the third roller, the total reverse curvature can be controlled within the range of 1 / Pw-1.222 / Pw, and the residual curvature is in the same direction as the reverse curvature of the second roller;

[0033] The setting of the roll gap of the 4th roll ensures that the reverse curvature of the strip produced by the straightening force B of the 3rd roll satisfies that the reverse curvature is less than the minimum value of the elastic-plastic bending curvature, i.e., 1 / P 3 <1 / P w ;

[0034] Among them, 1 / P is the maximum value of elastic-plastic bending elastic curvature, 1 / Pw is the minimum value of elastic-plastic bending elastic curvature, 1 / Pw=2Re / Eh, Re is the yield stress of the strip, h is the thickness of the strip, and E is the elastic modulus of the strip.

[0035] After the blank is rigidly straightened by setting the reference gap of the roll gap at the inlet / outlet of the straightening machine as the initial roll gap, the total elongation coefficient and roll gap are recalculated by setting the end gap of 20 roll gaps as the target roll gap.

[0036] After the roll gap at the inlet / outlet of the straightening machine is set, the wire rod is straightened by the straightening machine and then enters the high-speed wire rolling mill for 20 passes for rolling;

[0037] The high-speed wire rod rolling mill selects 20 rolling passes according to the maximum pass elongation coefficient allowed by the elliptical-circular hole type system and the motor capacity of the rolling mill, and reasonably allocates the elongation coefficient of each pass according to the total elongation coefficient of the billet and the 20 rolling passes;

[0038] The setting of the total elongation coefficient of the billet in 20 passes of the high-speed wire rod rolling mill should be redistributed before entering the high-speed wire rod rolling mill after the roll gap is set at the inlet / outlet of the straightening machine.

[0039] Among them, the high-speed wire mill is based on the cross-sectional area from the 1st to the 20th pass and the pass parameters and roll gap value from the 1st to the 20th pass;

[0040] The 1st to 20th passes of the high-speed wire rod rolling mill are based on 150 2 The billet and product specifications are Φ17.3mm, and the total elongation coefficient is determined to be 95.76;

[0041] Among them, the elongation coefficient of the first pass is 1.296, and the roll gap is set to 19.5. The elongation coefficient of the 20th pass is 1.075, and the roll gap is set to 1.0.

[0042] According to 150 2 The cross-sectional area of ​​the billet from 1st to 20th pass and the elongation coefficient of 20 passes are used to determine the cross-sectional area of ​​the billet and product specifications of Φ17.3mm and the cross-sectional area of ​​the billet from 1st to 20th pass and the hole parameters and roll gap value from 1st to 20th pass.

[0043] The specific operations are as follows:

[0044] According to the billet 150 2 The billet and product specifications are Φ17.3mm, and the total elongation coefficient is determined to be 95.76.

[0045] According to the maximum pass elongation factor allowed by the elliptical-circular hole system and the motor capacity of the rolling mill, 20 passes were selected as the rolling pass.

[0046] There are 20 passes for roughing, intermediate rolling and pre-finishing rolling. The finishing mill must use two passes, so the finishing mill selects 2 passes, the finishing mill selects 19 and 20 passes, and the rest are empty passes. According to the total elongation coefficient of 95.76 and 20 rolling passes, the elongation coefficient of each pass is reasonably allocated.

[0047] The cross-sectional area of ​​each pass is determined based on the cross-sectional area of ​​the blank and the pass elongation coefficient.

[0048] Design the pass hole parameters and roll gap value according to the cross-sectional area of ​​each pass.

[0049] Guides and guards are designed and rolls, roll rings and guide and guard spare parts are manufactured and installed according to hole parameters.

[0050] Conduct trial production, summarize and correct the roller gap value of each pass to ensure process production stability and product dimensional accuracy.

[0051] According to the rolling specifications and the speed and transmission ratio of each pass of the finishing mill, the cross-sectional area (height x width) of the incoming rolled pieces entering the finishing mill is determined, and then the total elongation coefficient is determined according to the cross-sectional area of ​​the raw material billet and the finished product of the Morgan rolling mill. The elongation coefficient of each run is reasonably allocated with reference to the elongation coefficient recommended by the elliptical-circular hole type system, and the cross-sectional area (height x width) of each run is calculated according to the elongation coefficient. The hole type size of each run is newly designed, and the roll gap value of each run is re-given according to the empirical data of production deformation, and the rolls are matched and processed according to the hole type size, and debugging is carried out on the line. Finally, the process is smooth and the product dimensional accuracy meets the standard requirements.

[0052] The parameters of each pass of forming Φ17.3mm round steel from the 1st pass to the 20th pass are as follows:

[0053]

[0054]

[0055] The high-speed wire rod mill finishing mill adopts a single motor collective drive, and adjacent frames are vertically intersected at +45° / -45° and +75° / -15°. Different transmission ratios are formed between adjacent frames through a speed increaser, a cone box, and a roller box. The transmission ratio is fixed, and the speed ratio between two adjacent frames is fixed. The cross-sectional area of ​​the rolled pieces from the 1st to the 20th pass and the fixed transmission ratio ensure that the two adjacent frames in the 19th to the 20th pass group are micro-tension rolling.

[0056] The ellipse-circle-ellipse-circle...pass system is used inside the 19th to 20th passes. The cross-sectional area, i.e., height x width, of the incoming rolled piece entering the 19th to 20th passes is first determined according to the rolling specifications and the rotation speed and transmission ratio of the 19th to 20th passes.

[0057] A method for setting a new specification of roll gap for a high-speed wire rod rolling mill is applied to the field of high-speed wire rod production in the metallurgical industry, so that the process of producing Φ17.3mm round steel using a high-speed wire rod rolling mill is stable, steel pile accidents are reduced, and the utilization rate and hourly output of the rolling mill are improved.

[0058] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0059] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for setting a new roll gap specification for a high-speed wire rolling mill, characterized in that: Including the roll gap setting at the inlet / outlet of the straightener and the 20-pass parameter setting of the high-speed wire rod mill, the roll gap setting reference gap at the inlet / outlet of the straightener is used as the initial roll gap, the roll gap at the end of the 20-pass roll gap is set as the target roll gap, and the roll gap adjustment hydraulic cylinder lifting stroke corresponding to the target roll gap of each pair of rollers is calculated through the initial roll gap and the target roll gap; The high-speed wire rod mill includes roughing, intermediate rolling and pre-finishing rolling for a total of 20 times, of which the roughing mills are the 1st and 2nd stands, the intermediate rolling mills are the 3rd to 18th stands, the finishing mill is selected for 2 passes, and the finishing mills are selected for the 19th and 20th stands, and the rest are empty passes; According to the actual billet and product specifications, the total elongation coefficient is determined and reasonably allocated to each pass.

2. The method for setting a new roll gap specification for a high-speed wire rolling mill according to claim 1, characterized in that: The roller gap setting at the inlet / outlet of the straightening machine includes a straightening machine with an even number of frames, wherein the 4-roller structure is the main one, and the roller gap setting at the inlet of the straightening machine ensures that the reverse bending rate of roller 2 is 1 / P2=1 / P S , the residual curvature of the blank after the second reverse bending is zero; When the blank passes through the third roller, the total reverse curvature can be controlled within the range of 1 / Pw-1.222 / Pw, and the residual curvature is in the same direction as the reverse curvature of the second roller; The setting of the roll gap of the 4th roll ensures that the reverse curvature of the strip produced by the straightening force B of the 3rd roll satisfies that the reverse curvature is less than the minimum value of the elastic-plastic bending curvature, that is, 1 / P3<1 / P w ; Among them, 1 / Pw is the minimum value of elastic-plastic bending complex curvature, 1 / Pw=2Re / Eh, Re is the yield stress of the strip, h is the thickness of the strip, and E is the elastic modulus of the strip.

3. The method for setting a new roll gap specification for a high-speed wire rod rolling mill according to claim 2, characterized in that: After the roll gap at the inlet / outlet of the straightening machine is set, the wire rod is straightened by the straightening machine and then enters the high-speed wire rolling mill for 20 passes for rolling; The high-speed wire rod rolling mill selects 20 rolling passes according to the maximum pass elongation coefficient allowed by the elliptical-circular hole type system and the motor capacity of the rolling mill, and reasonably allocates the elongation coefficient of each pass according to the total elongation coefficient of the billet and the 20 rolling passes; The setting of the total elongation coefficient of the billet in 20 passes of the high-speed wire rod rolling mill should be redistributed after the roll gap is set at the inlet / outlet of the straightening machine and before entering the high-speed wire rod rolling mill.

4. The method for setting a new roll gap specification for a high-speed wire rolling mill according to claim 3, characterized in that: The 1st to 20th passes of the high-speed wire rod mill are based on 150 2 The billet and product specifications are Φ17.3mm, and the total elongation coefficient is determined to be 95.76; Among them, the elongation coefficient of the first pass is 1.296, and the roll gap is set to 19.5; the elongation coefficient of the 20th pass is 1.075, and the roll gap is set to 1.

0.

5. The method for setting a new roll gap specification for a high-speed wire rolling mill according to claim 4, characterized in that: According to 150 2 The cross-sectional area of ​​the billet from 1st to 20th pass and the elongation coefficient of 20 passes are used to determine the cross-sectional area of ​​the billet and product specifications of Φ17.3mm and the cross-sectional area of ​​the billet from 1st to 20th pass and the hole parameters and roll gap value from 1st to 20th pass.

6. The method for setting a new roll gap specification for a high-speed wire rolling mill according to claim 5, characterized in that: The parameters of each pass from the 1st to the 20th pass to form Φ17.3mm round steel are as follows:

7. The method for setting a new roll gap specification for a high-speed wire rolling mill according to claim 6, characterized in that: The high-speed wire rod mill finishing mill adopts a single motor collective drive, and adjacent frames are vertically intersected at +45° / -45° and +75° / -15°. Different transmission ratios are formed between adjacent frames through a speed increaser, a cone box, and a roller box. The transmission ratio is fixed, and the speed ratio between two adjacent frames is fixed. The cross-sectional area of ​​the rolled pieces from the 1st to the 20th pass and the fixed transmission ratio ensure that the two adjacent frames in the 19th to the 20th pass group are micro-tension rolling.

8. The method for setting a new roll gap specification for a high-speed wire rolling mill according to claim 7, characterized in that: The ellipse-circle-ellipse-circle...pass system is used inside the 19th to 20th passes. The cross-sectional area, i.e., height x width, of the incoming rolled piece entering the 19th to 20th passes is first determined according to the rolling specifications and the rotation speed and transmission ratio of the 19th to 20th passes.

9. A method for setting a new specification of roll gap for a high-speed wire rod rolling mill according to any one of claims 1 to 8 is applied to the field of high-speed wire rod production in the metallurgical industry.

Images