Energy-saving bar product rolling method

Abstract

The invention discloses an energy-saving bar product rolling method, and belongs to the technical field of steel rolling. In the process of rolling bar products with the specification of phi 10-phi 28, a first rough rolling mill and a fourth rough rolling mill are set to be flat-roll slotless rolling, a fifth rough rolling mill is set to be flat-bottom elliptical hole rolling, and a sixth rough rolling mill is set to be round hole rolling; sliding guides of the 1 #-6 # rough rolling mills are set to be adjustable open type guides, guide rollers of the 2 #, 4 # and 6 # inlet guides are set to be in a flat roller shape, and then rolling is conducted. The rolling power consumption is effectively reduced and the purpose of saving energy is achieved mainly by optimally designing the hole pattern system of the roughing mill and the guide size under the condition that the intermediate rolling mill and the finishing mill maintain the original process, and the method is easy to popularize and apply.

Description

Technical Field

[0001] This invention relates to the field of steel rolling technology, specifically to an energy-saving method for rolling bar products. Background Technology

[0002] Rolling is a plastic forming process that applies pressure to a metal billet using rotating rolls, reducing its cross-section and increasing its length. It falls under the category of metal processing and is mainly used to produce metal materials such as profiles, plates, and pipes. Based on temperature, it is divided into hot rolling (high-temperature processing) and cold rolling (room-temperature processing). The former can refine grains but is prone to residual stress, while the latter requires annealing to improve mechanical properties. According to the direction of the rolled material's movement, it can be divided into longitudinal rolling, transverse rolling, and skew rolling, corresponding to different roll rotation methods and material deformation paths.

[0003] A typical bar wire rod mill consists of 17 stands, divided into roughing mills (stands 1-6), intermediate mills (stands 7-10), and finishing mills (stands 11-17). In the production of ribbed steel bars with specifications of Φ10-Φ28, within the required rolling temperature range (1000℃-1050℃), the conventional rolling method results in smaller reductions in stands 1, 2, 3, and 4 for the material shape, leading to lower current values ​​(approximately 400mA) and motor power utilization of about 50%. Stands 5-10, however, have significantly higher current values ​​and higher motor power utilization of approximately 85%. As rolling progresses, the rolling temperature gradually decreases. The conventional rolling method fails to utilize the advantages of the high temperature and good plasticity of the initial rolling pass, resulting in high overall power consumption. Therefore, exploring a more energy-efficient rolling method is essential. Summary of the Invention

[0004] The purpose of this invention is to provide an energy-saving method for rolling bar products, addressing the aforementioned limitations of existing technologies. Current process dimensions only consider the inherent friction coefficient of the rolled material itself, neglecting external friction and the increasing friction coefficient of the rolling groove as rolling progresses. The actual friction coefficient in production is greater than the theoretically calculated coefficient. Based on the changes in the friction coefficient during actual production, the reduction is continuously increased, resulting in a stable and mature energy-saving process. This invention, while maintaining the original processes in the intermediate and finishing mills, leverages the advantages of the high temperature and good plasticity of the rolled material in the initial rolling pass, making it easier to reduce. Through optimized design of the roughing mill pass system and guide dimensions, the reduction in the initial rolling pass is increased (by increasing the reduction in mills 1, 2, and 3) to reduce the reduction pressure in the intermediate and finishing mills, thereby lowering the overall rolling power consumption and achieving energy savings.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides an energy-saving method for rolling bar products, comprising the following steps: Step (1): Set the No. 1-4 roughing mills to flat roll grooveless rolling, the No. 5 roughing mill to flat bottom elliptical hole rolling, and the No. 6 roughing mill to round hole rolling. Step (2): The sliding guides of the 1#-6# roughing mills are set as adjustable open guides, and the guide rolls of the 2#, 4# and 6# inlet guides are set as flat rolls. The dimensions of the sliding guide grooves for roughing mills #1-#6 are as follows: Guide channel height H_guide = H_material + 8K; The guide groove width B_guide = B_material + 10K; In the formula, K is the guide groove clearance coefficient, and B is the material width; Step (3), rolling: The rolling temperature control range is 1000℃-1050℃.

[0006] Furthermore, for roughing mills #1 to #5, K is taken as 1-3.5; for roughing mill #6, K is taken as 0.2-2.0.

[0007] Furthermore, the process material dimensions of the six rolling mills in the rolling sequence are 105.00mm×184.00mm, 118.00mm×126.00mm, 75.00mm×146.00mm, 90.00mm×96.00mm, 59.00mm×110.00mm, and 75.00mm×75.00mm.

[0008] Furthermore, according to the rolling sequence, the elongation coefficients are 1.210, 1251, 1.260, 1.262, 1.363, and 1.366, respectively.

[0009] Furthermore, the roll diameter D of roughing mills 1-6 is 650mm for mills 1-4 and 520mm for mills 5 and 6.

[0010] Furthermore, the height of the inlet guides for roughing mills 1#-6# are 190 mm, 115 mm, 140 mm, 81 mm, 110 mm, and 65 mm respectively, and the width is 170 mm, 185 mm, 140 mm, 160 mm, 110 mm, and 120 mm respectively.

[0011] Furthermore, the exit guide dimensions of roughing mills 1-6 are as follows: height 210 mm, 140 mm, 110 mm, 125 mm, 90 mm, 95 mm, and width 180 mm, 140 mm, 160 mm, 125 mm, 125 mm, 95 mm, respectively.

[0012] The beneficial effects of this invention are: 1. This invention utilizes the advantages of high workpiece temperature and good plasticity in the initial rolling pass, facilitating reduction, to increase the reduction amount in mills 1, 2, and 3, thereby reducing the reduction pressure in the intermediate and finishing mills, lowering the overall rolling power consumption, and achieving energy saving. After implementation, the motor power utilization rate of mills 1, 2, and 3 reached approximately 75%, an increase of 25%. The current value of mills 1-10 is approximately 850mA. Balanced utilization of the motors in the roughing and intermediate rolling mills is achieved, reducing the overall rolling power consumption by 20%.

[0013] 2. This invention improves production continuity and increases output. It reduces holding time and lowers coal consumption. It reduces the requirement for excessively high heating temperatures, minimizing grain growth. Simultaneously, the high pressure applied at high temperatures facilitates the crushing and refining of coarse grains, thus improving the mechanical properties of the product. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the pass system used for roughing rolling, where pass types 1, 2, 3, 4, 5, and 6 are shown from left to right. Detailed Implementation

[0015] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0016] To enable those skilled in the art to better understand the technical solution of this application, the technical solution of this application will be described in detail below with reference to specific embodiments.

[0017] The bar wire rod mill group consists of 17 stands, divided into roughing mills (stands 1-6), intermediate mills (stands 7-10), and finishing mills (stands 11-17). The motors for stands 1, 2, 3, 4, and 13 are all 680 kW; stands 5-11 are all 800 kW; stands 12, 14, and 15 are all 1000 kW; and stands 16 and 17 are all 1000 kW. The roll diameter for stands 1-4 is 650 mm; for stands 5-10 it is 520 mm; and for stands 11-17 it is 430 mm.

[0018] The billets after being taken out of the furnace are transported to the first rolling mill of the roughing mill train (1# rolling mill) by the conveying roller table, and the rolling start temperature is controlled within the range of 1000°C - 1050°C. The rolled pieces are subjected to non-twist rolling in the 6-stand roughing mill train with flat and vertical stands arranged alternately. After the head is cut off by the 1# flying shear, they enter the intermediate rolling mill train with 4 flat and vertical stands arranged alternately for non-twist rolling. The temperature when entering the intermediate rolling mill is about 940°C - 990°C, and the temperature of the rolled pieces from the start of rolling to entering the intermediate rolling mill drops by about 60°C on average. Micro-tension control rolling is adopted inside the roughing and intermediate rolling mill trains. The head and tail of the rolled pieces are cut off by the 2# flying shear, and then they enter the finishing mill train for rolling. The temperature when entering the finishing mill is about 900°C - 950°C, and the temperature of the rolled pieces from the start of rolling to entering the finishing mill drops by about 40°C on average. The steel product specifications are ribbed steel bars with a diameter range of Φ10 - Φ28.

[0019] In the embodiments of the present invention, the test materials not specifically described are all conventional test materials in the art and can be obtained through commercial channels.

[0020] Example 1 An energy-saving rolling method for bar products, comprising: Step (1), set the 1# - 4# roughing mills of the roughing mill as flat roll non-groove rolling, set the 5# roughing mill as flat-bottom oval pass rolling, and set the 6# roughing mill as round pass rolling; Among them, the roll arrangement for the 1# - 6# roughing mill stands: D_work + H_material ≤ D_max; In the formula, D_work is the working roll diameter; H_material is the material height; D_max is the maximum allowable roll diameter of the rolling mill; Step (2), set the sliding guides of the 1# - 6# roughing mills as adjustable open-type guides, and set the guide rollers of the inlet guides of the 2#, 4#, and 6# as flat roll shapes; The sliding guide groove dimensions of the 1# - 6# roughing mills are as follows: Guide groove height H_guide = H_material + ⑧K; Guide groove width B_guide = B_material + 10K; In the formula, K is the guide groove clearance coefficient, and B_material is the material width; Step (3), rolling: The rolling start temperature is controlled within the range of 1000°C - 1050°C.

[0021] For the 1# roughing mill and the 5# roughing mill, K takes 1, and for the 6# roughing mill, K takes 0.2.

[0022] According to the rolling sequence, the process stock shape dimensions of the six rolling mills are successively 105.00 mm × 184.00 mm, 118.00 mm × 126.00 mm, 75.00 mm × 146.00 mm, 90.00 mm × 96.00 mm, 59.00 mm × 110.00 mm, and 75.00 mm × 75.00 mm.

[0023] According to the rolling sequence, the elongation coefficients are successively 1.210, 1.251, 1.260, 1.262, 1.363, and 1.366.

[0024] The working roll diameter D of the 1#-6# roughing mills: the roll diameters of the 1st - 4th rolling mills are 650 mm, and the roll diameters of the 5th and 6th rolling mills are 520 mm.

[0025] The outlet guide dimensions of the 1#-6# roughing mills are successively 210 mm, 140 mm, 110 mm, 125 mm, 90 mm, and 95 mm in height, and successively 180 mm, 140 mm, 160 mm, 125 mm, 125 mm, and 95 mm in width.

[0026] After implementation, for the 1st, 2nd, and 3rd rolling mills, the motor power utilization rate reaches 76%, with a 25% increase in the motor power utilization rate. The current values of 1 - 10 are all approximately 850 mA. The balanced utilization of the rough and medium rolling motors is achieved, and the overall rolling power consumption is reduced by 20%.

[0027] Example 2 An energy-saving bar product rolling method includes: Step (1): Set the 1#-4# roughing mills as flat roll non-groove rolling, the 5# roughing mill as flat-bottom oval pass rolling, and the 6# roughing mill as round pass rolling; Among them, the roll configuration for the 1#-6# roughing mills: D + H ≤ Dmax; In the formula, D is the working roll diameter; H is the stock shape height; Dmax is the maximum allowable roll diameter of the rolling mill; Step (2): Set the sliding guides of the 1#-6# roughing mills as adjustable open-type guides, and set the guide rollers of the 2#, 4#, and 6# inlet guides as flat roll shapes; The sliding guide groove dimensions of the 1#-6# roughing mills are as follows: The guide groove height H = H + 8K; The guide groove width B = B + 10K; In the formula, K is the guide groove clearance coefficient, and B is the stock shape width; Step (3): Rolling: The rolling start temperature control range is 1000°C - 1050°C.

[0028] K is 3.5 for roughing mill #1 and roughing mill #5, and K is 2.0 for roughing mill #6.

[0029] The process material dimensions of the six rolling mills according to the rolling sequence are 105.00mm×184.00mm, 118.00mm×126.00mm, 75.00mm×146.00mm, 90.00mm×96.00mm, 59.00mm×110.00mm, and 75.00mm×75.00mm.

[0030] According to the rolling sequence, the elongation coefficients are 1.210, 1251, 1.260, 1.262, 1.363, and 1.366, respectively.

[0031] The roll diameter D of roughing mills 1#-6# is as follows: the roll diameter of mills 1-4 is 650mm, and the roll diameter of mills 5 and 6 is 520mm.

[0032] The exit guide dimensions of roughing mills 1#-6# are 210mm, 140mm, 110mm, 125mm, 90mm, and 95mm in height, and 180mm, 140mm, 160mm, 125mm, 125mm, and 95mm in width, respectively.

[0033] After implementation, the motor power utilization rate of rolling mills 1, 2, and 3 reached 74%, an increase of 25%. The current value of mills 1-10 was approximately 850mA. Balanced utilization of the motors in the roughing and intermediate rolling mills was achieved, reducing overall rolling power consumption by 20%.

[0034] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for rolling energy-saving bar products, characterized in that, Includes the following steps: Step (1): Set the No. 1-4 roughing mills to flat roll grooveless rolling, the No. 5 roughing mill to flat bottom elliptical hole rolling, and the No. 6 roughing mill to round hole rolling. Step (2): The sliding guides of the 1#-6# roughing mills are set as adjustable open guides, and the guide rolls of the 2#, 4# and 6# inlet guides are set as flat rolls. The dimensions of the sliding guide grooves for roughing mills #1-#6 are as follows: Guide channel height H_guide = H_material + 8K; The guide groove width B_guide = B_material + 10K; In the formula, K is the guide groove clearance coefficient, and B is the material width; Step (3), rolling: The rolling temperature control range is 1000℃-1050℃.

2. The energy-saving bar rolling method according to claim 1, characterized in that, For roughing mills #1 to #5, K is 1-3.5; for roughing mill #6, K is 0.2-2.

0.

3. The energy-saving bar rolling method according to claim 1, characterized in that, The process material dimensions of the six rolling mills according to the rolling sequence are 105.00mm×184.00mm, 118.00mm×126.00mm, 75.00mm×146.00mm, 90.00mm×96.00mm, 59.00mm×110.00mm, and 75.00mm×75.00mm.

4. The energy-saving bar rolling method according to claim 3, characterized in that, According to the rolling sequence, the elongation coefficients are 1.210, 1251, 1.260, 1.262, 1.363, and 1.366, respectively.

5. The energy-saving bar rolling method according to claim 1, characterized in that, The roll diameter D of roughing mills 1-6 is 650mm, and the roll diameter of mills 5 and 6 is 520mm.

6. The energy-saving bar rolling method according to claim 1, characterized in that, The inlet guide dimensions of roughing mills 1#-6# are 190 mm, 115 mm, 140 mm, 81 mm, 110 mm, and 65 mm in height, and 170 mm, 185 mm, 140 mm, 160 mm, 110 mm, and 120 mm in width, respectively.

7. The energy-saving bar rolling method according to claim 1, characterized in that, The exit guide dimensions of roughing mills 1#-6# are 210 mm, 140 mm, 110 mm, 125 mm, 90 mm, and 95 mm in height, and 180 mm, 140 mm, 160 mm, 125 mm, 125 mm, and 95 mm in width, respectively.

Images