Water distribution method and system for secondary cooling of square blank at high pulling speed

Abstract

The invention relates to the technical field of square billet bulging treatment, in particular to a high-pulling-speed square billet secondary cooling water distribution method and system.The method comprises the steps that water pipelines are arranged on the left side, the right side, the inner arc and the outer arc of a square billet respectively, and the water pipelines on the left side and the right side are combined; a cooling area where the square billet passes through is divided into five parts, the water flow of the inner arc pipeline serves as the reference, and the water flow ratio of the inner arc pipeline to the outer arc pipeline of each cooling area, the water flow ratio of the inner arc pipeline to the combined pipelines on the two sides and the total flow of each cooling area are set; and the bulging amount of the square billet at different pulling speeds is smaller than a set threshold value. By controlling the water flow ratio of the square billet in the inner arcs to the outer arcs and the inner arcs to the sides of the five cooling areas and the total water flow of the five cooling areas, the bulging problem of the square billet is solved.

Description

Technical Field

[0001] The invention relates to the technical field of billet bulging treatment, and in particular to a billet secondary cooling water distribution method and system at a high drawing speed. Background Art

[0002] Currently using 160×160mm 2 When producing alloyed low-carbon special steel from small square billets, the drawing speed is below 2.5m / min. This is mainly because this type of steel is prone to bulging defects. When the bulging amount exceeds 4mm, the billet has to be scrapped. Therefore, in order to increase the drawing speed of low-carbon special steel, a special cooling method is required to reduce the occurrence of bulging.

[0003] When the drawing speed is increased, the inner and outer arc sides of the ingot are constrained by the straightening machine, so bulging defects are not easy to occur on the inner and outer arc sides. However, the side of the ingot is prone to bulging defects at high drawing speeds due to the lack of mechanical constraints. Especially when the drawing speed is increased to above 3.0m / min, the bulging amount of low carbon steel even exceeds 10mm, which seriously limits the high-speed drawing production of low carbon steel.

[0004] The patent publication number is CN220462162U, which discloses a method of installing three rows of foot rollers on a crystallizer of a small square billet to solve the bulging problem of the billet.

[0005] The patent with publication number CN219817964U discloses a wide-edge foot roller of a continuous casting machine with an auxiliary device, which uses a support roller supporting the foot roller and a mounting frame for mounting the support roller to offset the outward force of the billet, thereby eliminating the bulging of the billet.

[0006] The patent with publication number CN 215614932 U discloses a clamping roller device for preventing bulging defects, which avoids bulging by mechanical squeezing.

[0007] The patent publication number is CN 212350311 U, which discloses a double-row foot roller design to improve the de-squareness and bulging of the casting.

[0008] The patent with publication number CN 210996369 U discloses a three-row narrow-surface foot roller design to prevent bulging.

[0009] The patent with publication number CN 210547950 U discloses a device for cooling the foot roller to increase the rigidity of the foot roller to avoid bulging.

[0010] Patent CN 206185109 U discloses a secondary cooling device for a high-speed billet or round billet continuous casting machine, which divides the secondary cooling zone into a plurality of guide sections, and then divides the secondary cooling zone into a plurality of cooling sections, and performs cooling in different ways to improve bulging defects.

[0011] The patent with publication number CN 114905024A discloses a control method for secondary cooling water distribution of threaded steel billets, provides a formula for cooling water flow and drawing speed, and provides coefficient values ​​under different drawing speed ranges.

[0012] The above method has the following problems:

[0013] 1. The device needs to be structurally improved, and the cost of transformation is high;

[0014] 2. The calculation accuracy of the model is low. Summary of the invention

[0015] In view of the shortcomings of the existing methods, the present invention solves the problem of bulging on the side of the billet by controlling the water flow ratio between the inner arc and the outer arc, the inner arc and the side of the billet in the five cooling zones and the total water flow in the five cooling zones.

[0016] The technical solution adopted by the present invention is: a method for secondary cooling and water distribution of a flat billet at a high drawing speed comprises the following steps:

[0017] Step 1: Set water pipes on the left side, right side, inner arc and outer arc of the billet respectively, and merge the left and right water pipes;

[0018] The steel composition of the square billet is: carbon content is 0.1%-0.25%, silicon content is 0.1-0.5%, manganese content is 0.1-1.0%, other elements are iron and residual elements, the billet thickness = 160mm, and the billet length and width = 160mm.

[0019] like Figure 3 Step 2: Divide the cooling zones through which the billet passes into five zones. Based on the water flow rate of the inner arc pipeline, set the water flow rate ratio of the inner arc pipeline to the outer arc pipeline, the water flow rate ratio of the inner arc pipeline to the combined pipelines on both sides, and the total flow rate of each cooling zone. Make the bulging amount on both sides of the billet less than the set threshold value at different drawing speeds.

[0020] Since the continuous casting machine is an arc-shaped continuous casting machine, the inner arc water will have a certain amount of residue on the ingot after cooling, while the outer arc water will not remain on the ingot, so the amount of outer arc water needs to be higher than that of inner arc water; in addition, after high drawing speed, low carbon steel will have more obvious side bulging, so it is necessary to increase the amount of side water to suppress the side bulging.

[0021] As a preferred embodiment of the present invention, the total flow of the five cooling zones includes: the flow rate Q1 of the foot roller cooling zone is in the range of [15, 28], the flow rate Q2 of the second cooling zone 1 is in the range of [15, 20], the flow rate Q3 of the second cooling zone 2 is in the range of [4, 10], the flow rate Q4 of the second cooling zone 3 is in the range of [3, 4], and the flow rate Q4 of the second cooling zone 4 is in the range of [2, 4], unit m 3 / h.

[0022] As a preferred embodiment of the present invention, the water flow ratio of the inner arc pipeline and the outer arc pipeline is: Q 内 :Q 外 =1:A; the water flow ratio of the inner arc pipe and the combined pipes on both sides is Q 内 :Q 侧 =1:B; where the value range of A is [2, 3], and the value range of B is [3, 6].

[0023] As a preferred embodiment of the present invention, the total flow rate of each cooling zone is Q=Q 内 +Q 侧 +Q 外 .

[0024] As a preferred embodiment of the present invention, the pulling speed range is [3, 3.8], in units of m / min.

[0025] As a preferred embodiment of the present invention, the threshold value of the bulging amount is 4 mm.

[0026] As a preferred embodiment of the present invention, a secondary cooling water distribution system for a billet at high drawing speed includes: a memory for storing instructions executable by a processor; a processor for executing the instructions to implement a secondary cooling water distribution method for a billet at high drawing speed.

[0027] As a preferred embodiment of the present invention, a computer readable medium stores a computer program code, and when the computer program code is executed by a processor, a method for distributing water for secondary cooling of a billet under high drawing speed is implemented.

[0028] Beneficial effects of the present invention:

[0029] 1. The method of the present invention can increase the drawing speed of low-carbon steel billet to within 3.0m / min-4.0m / min, control the side bulging amount within 4mm, and the billet has no surface defects;

[0030] 2. This method is simple, convenient and easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a flow chart of the water distribution method for secondary cooling of a flat billet at a high drawing speed of the present invention;

[0032] Figure 2 It is a schematic diagram of the structure of the billet during rolling;

[0033] Figure 3 This is the right side view of the billet passing through five cooling zones;

[0034] Figure 4 It is a schematic diagram of the sprinkler pipeline;

[0035] Among them, 1. continuous casting billet; 2. left side; 3. inner arc; 4. right side; 5. outer arc; 6. spray pipeline of inner arc; 7. spray pipeline of outer arc; 8. spray pipeline combined on left and right sides. DETAILED DESCRIPTION

[0036] The present invention is further described below in conjunction with the accompanying drawings and embodiments. This figure is a simplified schematic diagram, which only illustrates the basic structure of the present invention in a schematic manner, and therefore it only shows the components related to the present invention.

[0037] When using small square billets to produce this type of steel, the shape of the ingot is maintained well during the low drawing speed process. However, as the drawing speed increases, the ingot begins to exhibit defects such as bulging and de-squareness. For the de-squareness defect, the crystallizer is mainly optimized; and for bulging, in addition to optimizing the crystallizer, the secondary cooling water also needs to be optimized.

[0038] like Figure 2 The middle blank has four faces in the direction of the throwing motion, including: inner arc, outer arc, left side and right side.

[0039] like Figure 1 As shown, a method for secondary cooling and water distribution of a billet under high drawing speed comprises the following steps:

[0040] Step 1: Set water pipes on the left side, right side, inner arc and outer arc of the billet respectively, and merge the left and right water pipes;

[0041] Among them, the water flow on the left and right sides is equal; that is, Q 左 =Q 右 =Q 侧 .

[0042] Step 2: Divide the cooling zones through which the billet passes into five zones, and set the water flow ratio of the inner arc pipeline to the outer arc pipeline, the water flow ratio of the inner arc pipeline to the combined pipelines on both sides, and the total flow of each cooling zone based on the water flow of the inner arc pipeline.

[0043] Embodiment 1:

[0044] Secondary cooling water distribution ratio:

[0045] like Figure 4The left side 2 and the right side 4 of the continuous casting billet 1 are sprayed by the same pipeline, the inner arc 3 of the continuous casting billet 1 is sprayed by a single pipeline, and the outer arc 5 of the continuous casting billet 1 is sprayed by a single pipeline.

[0046] The water flow rate of the combined spray pipe 8 on the left and right sides is defined as Q 侧 The water flow rate of the inner arc spray pipe 6 is defined as Q 内 The water flow rate of the outer arc spray line 7 is defined as Q 外 , with Q 内 As the benchmark, Q 内 :Q 外 =1:2; Q 内 :Q 侧 =1:3;

[0047] Distribution ratio of secondary cooling water to each zone:

[0048] like Figure 3 As shown, the cooling area is divided into 5 areas, including: foot roll cooling area, second cooling area 1, second cooling area 2, second cooling area 3, second cooling area 3, second cooling area 4; the water flow rates of the first to fifth cooling areas are Q1, Q2, Q3, Q4, Q5, respectively, in m 3 / h; the flow rate values ​​are 15, 15, 5, 3, 3.

[0049] The bulge on the left and right sides of the ingot produced at a pulling speed of 3.2m / min is about 2mm.

[0050] Embodiment 2:

[0051] Secondary cooling water distribution ratio:

[0052] The water flow rate of the combined spray pipe 8 on the left and right sides is defined as Q 侧 The water flow rate of the inner arc spray pipe 6 is defined as Q 内 The water flow rate of the outer arc spray line 7 is defined as Q 外 , with Q 内 As the benchmark, Q 内 :Q 外 =1:2.5;Q 内 :Q 侧 =1:4;

[0053] Distribution ratio of secondary cooling water to each zone:

[0054] The water flow rates of the first to fifth cooling zones are Q1, Q2, Q3, Q4, and Q5, respectively, in m3 / h; the flow rates are 18, 15, 4, 4, and 2;

[0055] The bulging amount of the left and right sides of the ingot produced at a pulling speed of 3.0m / min is about 1mm.

[0056] Embodiment 3:

[0057] Secondary cooling water distribution ratio:

[0058] The water flow rate of the combined spray pipe 8 on the left and right sides is defined as Q 侧 The water flow rate of the inner arc spray pipe 6 is defined as Q 内 The water flow rate of the outer arc spray line 7 is defined as Q 外 , with Q 内 As the benchmark, Q 内 :Q 外 =1:2; Q 内 :Q 侧 =1:4.5;

[0059] Distribution ratio of secondary cooling water to each zone:

[0060] The water flow rates of the first to fifth cooling zones are Q1, Q2, Q3, Q4, and Q5, respectively, in m3 / h; the flow rates are 18, 18, 4, 3, and 3.

[0061] The bulge on the left and right sides of the ingot produced at a pulling speed of 3.5m / min is about 2mm.

[0062] Embodiment 4:

[0063] Secondary cooling water distribution ratio:

[0064] The water flow rate of the combined spray pipe 8 on the left and right sides is defined as Q 侧 The water flow rate of the inner arc spray pipe 6 is defined as Q 内 The water flow rate of the outer arc spray line 7 is defined as Q 外 , with Q 内 As the benchmark, Q 内 :Q 外 =1:2; Q 内 :Q 侧 =1:4.5;

[0065] Distribution ratio of secondary cooling water to each zone:

[0066] The water flow rates of the first to fifth cooling zones are Q1, Q2, Q3, Q4, and Q5, respectively, in m3 / h; the flow rates are 20, 20, 8, 4, and 3.

[0067] The bulging amount of the left and right sides of the ingot produced at a pulling speed of 3.5m / min is about 1mm.

[0068] Embodiment 5:

[0069] Secondary cooling water distribution ratio:

[0070] The water flow rate of the combined spray pipe 8 on the left and right sides is defined as Q 侧The water flow rate of the inner arc spray pipe 6 is defined as Q 内 The water flow rate of the outer arc spray line 7 is defined as Q 外 , with Q 内 As the benchmark, Q 内 :Q 外 =1:2; Q 内 :Q 侧 =1:5;

[0071] Distribution ratio of secondary cooling water to each zone:

[0072] The water flow rates of the first to fifth cooling zones are Q1, Q2, Q3, Q4, and Q5, respectively, in m3 / h; the flow rates are 20, 15, 4, 3, and 3.

[0073] The bulge on the left and right sides of the ingot produced at a pulling speed of 3.8m / min is about 2mm.

[0074] Embodiment 6:

[0075] Secondary cooling water distribution ratio:

[0076] The water flow rate of the combined spray pipe 8 on the left and right sides is defined as Q 侧 The water flow rate of the inner arc spray pipe 6 is defined as Q 内 The water flow rate of the outer arc spray line 7 is defined as Q 外 , with Q 内 As the benchmark, Q 内 :Q 外 =1:3; Q 内 :Q 侧 =1:5;

[0077] Distribution ratio of secondary cooling water to each zone:

[0078] The water flow rates of the first to fifth cooling zones are Q1, Q2, Q3, Q4, and Q5, respectively, in m3 / h; the flow rates are 22, 20, 8, 4, and 3;

[0079] The bulge on the left and right sides of the ingot produced at a pulling speed of 3.8m / min is about 2mm.

[0080] Embodiment 7:

[0081] Secondary cooling water distribution ratio:

[0082] The water flow rate of the combined spray pipe 8 on the left and right sides is defined as Q 侧 The water flow rate of the inner arc spray pipe 6 is defined as Q 内 The water flow rate of the outer arc spray line 7 is defined as Q 外 , with Q 内 As the benchmark, Q 内 :Q外 =1:3; Q 内 :Q 侧 =1:6;

[0083] Distribution ratio of secondary cooling water to each zone:

[0084] The water flow rates of the first to fifth cooling zones are Q1, Q2, Q3, Q4, and Q5, respectively, in m3 / h; the flow rates are 25, 20, 10, 4, and 3.

[0085] The bulging amount of the left and right sides of the ingot produced at a pulling speed of 3.8m / min is about 1mm.

[0086] Embodiment 8:

[0087] Secondary cooling water distribution ratio:

[0088] The water flow rate of the combined spray pipe 8 on the left and right sides is defined as Q 侧 The water flow rate of the inner arc spray pipe 6 is defined as Q 内 The water flow rate of the outer arc spray line 7 is defined as Q 外 , with Q 内 As the benchmark, Q 内 :Q 外 =1:3; Q 内 :Q 侧 =1:6;

[0089] Distribution ratio of secondary cooling water to each zone:

[0090] The water flow rates of the first to fifth cooling zones are Q1, Q2, Q3, Q4, and Q5, respectively, in m3 / h; the flow rates are 28, 20, 10, 4, and 4.

[0091] The bulge on the left and right sides of the ingot produced at a pulling speed of 4.0m / min is about 4mm.

[0092] The following is a comparative example under the condition of balanced water volume, and the values ​​of A and B are not within the scope of this patent.

[0093] Comparative Example 1:

[0094] Secondary cooling water distribution ratio:

[0095] The water flow rate of the combined spray pipe 8 on the left and right sides is defined as Q 侧 The water flow rate of the inner arc spray pipe 6 is defined as Q 内 The water flow rate of the outer arc spray line 7 is defined as Q 外 , with Q 内 As the benchmark, Q 内 :Q 外 =1:1;Q 内 :Q 侧=1:2;

[0096] Distribution ratio of secondary cooling water to each zone:

[0097] The water flow rates of the first to fifth cooling zones are Q1, Q2, Q3, Q4, and Q5, respectively, in m 3 / h; the flow rate values ​​are 15, 15, 5, 3, 3.

[0098] The bulge on the left and right sides of the ingot produced at a pulling speed of 3.2m / min is about 6mm.

[0099] Comparative Example 2:

[0100] Secondary cooling water distribution ratio:

[0101] The water flow rate of the combined spray pipe 8 on the left and right sides is defined as Q 侧 The water flow rate of the inner arc spray pipe 6 is defined as Q 内 The water flow rate of the outer arc spray line 7 is defined as Q 外 , with Q 内 As the benchmark, Q 内 :Q 外 =1:1;Q 内 :Q 侧 =1:2;

[0102] Distribution ratio of secondary cooling water to each zone:

[0103] The water flow rates of the first to fifth cooling zones are Q1, Q2, Q3, Q4, and Q5, respectively, in m3 / h; the flow rates are 18, 15, 4, 4, and 2;

[0104] The bulge on the left and right sides of the ingot produced at a pulling speed of 3.0m / min is about 6mm.

[0105] Comparative Example 3:

[0106] Secondary cooling water distribution ratio:

[0107] The water flow rate of the combined spray pipe 8 on the left and right sides is defined as Q 侧 The water flow rate of the inner arc spray pipe 6 is defined as Q 内 The water flow rate of the outer arc spray line 7 is defined as Q 外 , with Q 内 As the benchmark, Q 内 :Q 外 =1:1;Q 内 :Q 侧 =1:2;

[0108] Distribution ratio of secondary cooling water to each zone:

[0109] The water flow rates of the first to fifth cooling zones are Q1, Q2, Q3, Q4, and Q5, respectively, in m3 / h; the flow rates are 18, 18, 4, 3, and 3.

[0110] The bulge on the left and right sides of the ingot produced at a pulling speed of 3.5m / min is about 8mm.

[0111] Comparative Example 4:

[0112] Secondary cooling water distribution ratio:

[0113] The water flow rate of the combined spray pipe 8 on the left and right sides is defined as Q 侧 The water flow rate of the inner arc spray pipe 6 is defined as Q 内 The water flow rate of the outer arc spray line 7 is defined as Q 外 , with Q 内 As the benchmark, Q 内 :Q 外 =1:1;Q 内 :Q 侧 =1:2;

[0114] Distribution ratio of secondary cooling water to each zone:

[0115] The water flow rates of the first to fifth cooling zones are Q1, Q2, Q3, Q4, and Q5, respectively, in m3 / h; the flow rates are 20, 20, 8, 4, and 3.

[0116] The bulge on the left and right sides of the ingot produced at a pulling speed of 3.5m / min is about 7mm.

[0117] Comparative Example 5:

[0118] Secondary cooling water distribution ratio:

[0119] The water flow rate of the combined spray pipe 8 on the left and right sides is defined as Q 侧 The water flow rate of the inner arc spray pipe 6 is defined as Q 内 The water flow rate of the outer arc spray line 7 is defined as Q 外 , with Q 内 As the benchmark, Q 内 :Q 外 =1:1;Q 内 :Q 侧 =1:2;

[0120] Distribution ratio of secondary cooling water to each zone:

[0121] The water flow rates of the first to fifth cooling zones are Q1, Q2, Q3, Q4, and Q5, respectively, in m3 / h; the flow rates are 20, 15, 4, 3, and 3.

[0122] The bulge on the left and right sides of the ingot produced at a pulling speed of 3.8m / min is about 8mm.

[0123] Comparative Example 6:

[0124] Secondary cooling water distribution ratio:

[0125] The water flow rate of the combined spray pipe 8 on the left and right sides is defined as Q 侧 The water flow rate of the inner arc spray pipe 6 is defined as Q 内 The water flow rate of the outer arc spray line 7 is defined as Q 外 , with Q 内 As the benchmark, Q 内 :Q 外 =1:1;Q 内 :Q 侧 =1:2;

[0126] Distribution ratio of secondary cooling water to each zone:

[0127] The water flow rates of the first to fifth cooling zones are Q1, Q2, Q3, Q4, and Q5, respectively, in m3 / h; the flow rates are 22, 20, 8, 4, and 3;

[0128] The bulge on the left and right sides of the ingot produced at a pulling speed of 3.8m / min is about 8mm.

[0129] Comparative Example 7:

[0130] Secondary cooling water distribution ratio:

[0131] The water flow rate of the combined spray pipe 8 on the left and right sides is defined as Q 侧 The water flow rate of the inner arc spray pipe 6 is defined as Q 内 The water flow rate of the outer arc spray line 7 is defined as Q 外 , with Q 内 As the benchmark, Q 内 :Q 外 =1:1;Q 内 :Q 侧 =1:2;

[0132] Distribution ratio of secondary cooling water to each zone:

[0133] The water flow rates of the first to fifth cooling zones are Q1, Q2, Q3, Q4, and Q5, respectively, in m3 / h; the flow rates are 25, 20, 10, 4, and 3.

[0134] The bulge on the left and right sides of the ingot produced at a pulling speed of 3.8m / min is about 7mm.

[0135] Comparative Example 8:

[0136] Secondary cooling water distribution ratio:

[0137] The water flow rate of the combined spray pipe 8 on the left and right sides is defined as Q 侧 The water flow rate of the inner arc spray pipe 6 is defined as Q 内 The water flow rate of the outer arc spray line 7 is defined as Q 外 , with Q 内 As the benchmark, Q 内 :Q 外 =1:1;Q 内 :Q 侧 =1:2;

[0138] Distribution ratio of secondary cooling water to each zone:

[0139] The water flow rates of the first to fifth cooling zones are Q1, Q2, Q3, Q4, and Q5, respectively, in m3 / h; the flow rates are 28, 20, 10, 4, and 4.

[0140] The bulge on the left and right sides of the ingot produced at a pulling speed of 4.0m / min is about 8mm.

[0141] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A method for secondary cooling and water distribution of a billet under high drawing speed, characterized in that: The following steps are involved: Step 1: Set water pipes on the left side, right side, inner arc and outer arc of the billet respectively, and merge the left and right water pipes; Step 2: Divide the cooling zones through which the billet passes into five zones, and set the water flow ratio of the inner arc pipeline to the outer arc pipeline, the water flow ratio of the inner arc pipeline to the combined pipelines on both sides, and the total flow of each cooling zone based on the water flow of the inner arc pipeline in each cooling zone; so that the bulging amount on both sides of the billet at different drawing speeds is less than the set threshold.

2. The method for secondary cooling and water distribution of a billet under high drawing speed according to claim 1, characterized in that: The total flow of the five cooling zones includes: the flow of the foot roller cooling zone Q1 has a value range of [15, 28], the flow of the second cooling zone 1 Q2 has a value range of [15, 20], the flow of the second cooling zone 2 Q3 has a value range of [4, 10], the flow of the second cooling zone 3 Q4 has a value range of [3, 4], and the flow of the second cooling zone 4 Q4 has a value range of [2, 4], unit m 3 / h.

3. The method for secondary cooling and water distribution of a billet under high drawing speed according to claim 2, characterized in that: Water flow ratio Q of inner arc pipeline and outer arc pipeline 内 :Q 外 =1: A; water flow ratio Q of the inner arc pipe and the combined pipes on both sides 内 :Q 侧 =1:B; where the value range of A is [2, 3], and the value range of B is [3, 6].

4. The method for secondary cooling and water distribution of a billet under high drawing speed according to claim 3, characterized in that: The total flow rate of each cooling zone is Q = Q 内 +Q 侧 +Q 外 .

5. The method for secondary cooling and water distribution of a billet under high drawing speed according to claim 1, characterized in that: The pulling speed range is [3, 3.8], unit is m / min.

6. The method for secondary cooling and water distribution of a billet under high drawing speed according to claim 1, characterized in that: The threshold for bulging is 4 mm.

7. The secondary cooling water distribution system for the billet under high drawing speed is characterized by: include: a memory for storing instructions executable by a processor; A processor, used for executing instructions to implement the method for secondary cooling water distribution of a flat billet at a high drawing speed as described in any one of claims 1-6.

8. A computer readable medium storing a computer program code, characterized in that: The computer program code, when executed by a processor, implements the method for secondary cooling water distribution of a flat billet at a high drawing speed as described in any one of claims 1 to 6.

Images