Method for cutting a steel sheet slab

Abstract

The application discloses a steel plate slab cutting method, which comprises the following steps: A selecting a gas source: the cutting gas source uses natural gas, and the natural gas pressure, preheating oxygen pressure and cutting oxygen pressure are controlled; B controlling parameters: when the pulling speed is below 0.8 m / min, if the section surface is 1250 mm, the gun speed is controlled to be 220-260 mm / min, the cutting time is controlled to be 5.6-4.8 min, and the trolley walking time is controlled to be greater than 9.5 min; if the section surface is 1520 mm, the gun speed is controlled to be 220-260 mm / min, the cutting time is controlled to be 6.9-5.9 min, and the trolley walking time is controlled to be greater than 9.5 min; C cutting: the slab head is cut by double guns when starting the machine, and the cutting lines are kept on the same straight line. The application can solve the problems of poor cutting quality of the existing steel plate slab and influence on the next process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of steel manufacturing and its equipment, in particular to a cutting method for cutting steel slab with natural gas. BACKGROUND

[0002] At present, the steel slab cutting in many continuous casting workshops generally uses propane gas as the cutting fuel gas source. Since the pressure of propane gas is unstable when used as the cutting gas source, the personnel operation cannot effectively follow up the cutting, and the cutting slit is large. The large cutting slit is measured by measuring tools, and it is found that the slit width is greater than 5mm-8mm, and the double-gun cutting slit is not flat, forming a misalignment. The slab cutting forms a molten edge, and the above phenomena will affect the processing quality of the next process-rolling, resulting in that the final product quality cannot be well guaranteed. SUMMARY

[0003] The present application solves the problem of providing a steel slab cutting method to solve the poor cutting quality of the existing steel slab and the problem of affecting the next process.

[0004] In order to solve the above problems, the technical scheme of the present application is as follows: the steel slab cutting method includes the following steps:

[0005] A selects the gas source: the cutting gas source uses natural gas, the natural gas pressure is controlled at 0.03-0.05 Mpa, the preheating oxygen pressure is controlled at 0.25-0.4 Mpa, and the cutting oxygen pressure is controlled at 0.9-1.1 Mpa;

[0006] B control parameters: when the pulling speed is below 0.8m / min, if the segment surface is 1250mm, the gun speed is controlled at 220-260mm / min, the cutting time is controlled at 5.6-4.8min, and the trolley walking time is controlled at greater than 9.5min; if the segment surface is 1520mm, the gun speed is controlled at 220-260mm / min, the cutting time is controlled at 6.9-5.9min, and the trolley walking time is controlled at greater than 9.5min;

[0007] when the pulling speed is 0.8-1m / min, if the segment surface is 1250mm, the gun speed is controlled at 260-320mm / min, the cutting time is controlled at 4.8-3.9min, and the trolley walking time is controlled at 9.5-7.6min; if the segment surface is 1520mm, the gun speed is controlled at 260-320mm / min, the cutting time is controlled at 5.9-4.8min, and the trolley walking time is controlled at 9.5-7.6min;

[0008] When the pulling speed is 1.1–1.3 m / min, if the section is 1250 mm, the gun speed should be controlled at 330–350 mm / min, the cutting time at 3.8–3.6 min, and the trolley travel time at 6.9–5.9 min; if the section is 1520 mm, the gun speed should be controlled at 330–350 mm / min, the cutting time at 4.6–4.4 min, and the trolley travel time at 6.9–5.9 min.

[0009] When the pulling speed is 1.4–1.6 m / min, if the section is 1250 mm, the gun speed should be controlled at 360–380 mm / min, the cutting time at 3.5–3.8 min, and the trolley travel time at 5.4–4.7 min; if the section is 1520 mm, the gun speed should be controlled at 360–380 mm / min, the cutting time at 4.3–4.0 min, and the trolley travel time at 5.4–4.7 min.

[0010] When cold-cutting blanks, if the section size is 1250mm, the gun speed should be controlled at 150 mm / min and the cutting time at 8.3min; if the section size is 1520mm, the gun speed should be controlled at 150 mm / min and the cutting time at 10.0min.

[0011] C-cutting: The billet head is cut with two guns at startup, and the cutting lines are kept on the same straight line during dual-gun cutting; normal cutting is mainly done with a single gun; the preheating hot spot is selected in the inner flame.

[0012] A more specific solution to the above technical solution could be: in step B, select a low gun speed for cutting the blank; if an accident occurs or the machine needs to be restarted, use dual gun cutting.

[0013] Further steps include maintenance in step D: When replacing the cutting nozzle, use one pipe wrench to hold the cutting gun body and one wrench to remove the cutting nozzle. Since the angles and straightness of the cutting gun have been adjusted, it is strictly forbidden to remove the cutting nozzle directly with one wrench; the distance between the cutting nozzle and the blank surface should be controlled at 60-80mm; avoid deformation of the inner diameter of the cutting gun.

[0014] By adopting the above technical solution, the present invention has the following advantages compared with the prior art:

[0015] The steel slab cutting method uses natural gas as the cutting gas source. With proper parameter control, the cutting operation has been normal since production began, with a kerf of less than 5mm. The use of the cutting nozzle has resulted in stable cutting parameters, while also providing good quality assurance for the next process. Detailed Implementation

[0016] The embodiments of the present invention will be described in further detail below:

[0017] The method for cutting steel plate blanks includes the following steps:

[0018] A. Cutting gas source: natural gas is used for cutting gas source, the pressure of natural gas is controlled at 0.03-0.05 Mpa, the preheating oxygen pressure is controlled at 0.25-0.4 Mpa, and the cutting oxygen pressure is controlled at 0.9-1.1 Mpa; the main and auxiliary guns are ignited at the same time as the criterion; the cutting nozzle is selected from 1.9 type, 2.1 type and 2.3 type.

[0019] B. Control parameters: when the drawing speed is below 0.8 m / min, if the segment surface is 1250 mm, the gun speed is controlled at 220-260 mm / min, the cutting time is controlled at 5.6-4.8 min, and the trolley walking time is controlled at more than 9.5 min; if the segment surface is 1520 mm, the gun speed is controlled at 220-260 mm / min, the cutting time is controlled at 6.9-5.9 min, and the trolley walking time is controlled at more than 9.5 min.

[0020] When the drawing speed is 0.8-1 m / min, if the segment surface is 1250 mm, the gun speed is controlled at 260-320 mm / min, the cutting time is controlled at 4.8-3.9 min, and the trolley walking time is controlled at 9.5-7.6 min; if the segment surface is 1520 mm, the gun speed is controlled at 260-320 mm / min, the cutting time is controlled at 5.9-4.8 min, and the trolley walking time is controlled at 9.5-7.6 min.

[0021] When the drawing speed is 1.1-1.3 m / min, if the segment surface is 1250 mm, the gun speed is controlled at 330-350 mm / min, the cutting time is controlled at 3.8-3.6 min, and the trolley walking time is controlled at 6.9-5.9 min; if the segment surface is 1520 mm, the gun speed is controlled at 330-350 mm / min, the cutting time is controlled at 4.6-4.4 min, and the trolley walking time is controlled at 6.9-5.9 min.

[0022] When the drawing speed is 1.4-1.6 m / min, if the segment surface is 1250 mm, the gun speed is controlled at 360-380 mm / min, the cutting time is controlled at 3.5-3.8 min, and the trolley walking time is controlled at 5.4-4.7 min; if the segment surface is 1520 mm, the gun speed is controlled at 360-380 mm / min, the cutting time is controlled at 4.3-4.0 min, and the trolley walking time is controlled at 5.4-4.7 min.

[0023] When the cold billet is used, if the segment surface is 1250 mm, the gun speed is controlled at 150 mm / min, and the cutting time is controlled at 8.3 min; if the segment surface is 1520 mm, the gun speed is controlled at 150 mm / min, and the cutting time is controlled at 10.0 min.

[0024] C cutting: when the machine starts, the blank head double gun cutting is beneficial to the positioning of the next cutting gun; the cutting line remains in the same straight line when double gun cutting; normal cutting is mainly single gun; because the temperature of the cast blank is lower and the surface of the iron oxide skin is more, the required temperature and preheating time is longer, so the preheating point is selected in the inner flame (inner flame temperature is about 3000 °); confirm the work before starting the machine, confirm the gas, preheat oxygen, cutting oxygen, whether the particle water is normal, firepower, cutting wind line is insufficient, the cutting nozzle needs to be dredged or replaced.

[0025] D maintenance: when replacing the cutting nozzle, a pipe wrench is used to fix the cutting gun body and a wrench is used to remove the cutting nozzle. Since the cutting gun has been adjusted to the right angle and straightness, it is strictly forbidden to remove the cutting nozzle directly with a wrench. The distance between the cutting nozzle and the blank surface is controlled at 60-80 mm. Avoiding the deformation of the cutting gun origin inner diameter, causing the cutting edge line to be unstable and unable to normally cut through the blank. When shift change, ensure that all cutting nozzles are normal (flame does not flicker, has obvious wind line and is straight for normal cutting nozzle); ensure that the cutting gas source parameters are correct, whether the compressed air pressure head has lubricating oil, etc. If the gas source parameters deviate too much, the cutting nozzle must be replaced or the parameters must be adjusted on site. Lubricating oil must be replenished; must ensure that there are 4 complete cutting nozzles.

[0026] The plate slab cutting method of Bensteel adopts natural gas as the cutting gas source, and controls the parameters well. Since the production started, the cutting has been running normally, the cutting gap is less than 5 mm, the use of cutting nozzle, the cutting edge indicators are stable, at the same time also provides good quality guarantee for the next process.

Claims

1. A method of cutting a slab of steel sheet, characterized by It comprises the following steps: A. Selecting gas source: cutting gas source uses natural gas, natural gas pressure is controlled at 0.03-0.05 Mpa, preheating oxygen pressure is controlled at 0.25-0.4 Mpa, and cutting oxygen pressure is controlled at 0.9-1.1 Mpa; B. Controlling parameters: when the drawing speed is below 0.8 m / min, if the segment surface is 1250 mm, the gun speed is controlled at 220-260 mm / min, the cutting time is controlled at 5.6-4.8 min, and the trolley walking time is controlled at more than 9.5 min; if the segment surface is 1520 mm, the gun speed is controlled at 220-260 mm / min, the cutting time is controlled at 6.9-5.9 min, and the trolley walking time is controlled at more than 9.5 min; when the drawing speed is 0.8-1 m / min, if the segment surface is 1250 mm, the gun speed is controlled at 260-320 mm / min, the cutting time is controlled at 4.8-3.9 min, and the trolley walking time is controlled at 9.5-7.6 min; if the segment surface is 1520 mm, the gun speed is controlled at 260-320 mm / min, the cutting time is controlled at 5.9-4.8 min, and the trolley walking time is controlled at 9.5-7.6 min; when the drawing speed is 1.1-1.3 m / min, if the segment surface is 1250 mm, the gun speed is controlled at 330-350 mm / min, the cutting time is controlled at 3.8-3.6 min, and the trolley walking time is controlled at 6.9-5.9 min; if the segment surface is 1520 mm, the gun speed is controlled at 330-350 mm / min, the cutting time is controlled at 4.6-4.4 min, and the trolley walking time is controlled at 6.9-5.9 min; when the drawing speed is 1.4-1.6 m / min, if the segment surface is 1250 mm, the gun speed is controlled at 360-380 mm / min, the cutting time is controlled at 3.5-3.8 min, and the trolley walking time is controlled at 5.4-4.7 min; if the segment surface is 1520 mm, the gun speed is controlled at 360-380 mm / min, the cutting time is controlled at 4.3-4.0 min, and the trolley walking time is controlled at 5.4-4.7 min; when the drawing speed is 1.4-1.6 m / min, if the segment surface is 1250 mm, the gun speed is controlled at 360-380 mm / min, the cutting time is controlled at 3.5-3.8 min, and the trolley walking time is controlled at 5.4-4.7 min; if the segment surface is 1520 mm, the gun speed is controlled at 360-380 mm / min, the cutting time is controlled at 4.3-4.0 min, and the trolley walking time is controlled at 5.4-4.7 min; when the drawing speed is 1.4-1.6 m / min, if the segment surface is 1250 mm, the gun speed is controlled at 360-380 mm / min, the cutting time is controlled at 3.5-3.8 min, and the trolley walking time is controlled at 5.4-4.7 min; if the segment surface is 1520 mm, the gun speed is controlled at 360-380 mm / min, the cutting time is controlled at 4.3-4.0 min, and the trolley walking time is controlled at 5.4-4.7 min; 2. The slab cutting method of the steel sheet according to claim 1, characterized by: C. Cutting: blank head double-gun cutting when starting the machine, and the cutting line is kept in the same straight line when double-gun cutting; normal cutting mainly uses single gun; the preheating point is selected at the inner flame.

3. The steel sheet slab cutting method according to claim 2, characterized by: In step B, low gun speed cutting blank is selected.

4. The slab cutting method of any one of claims 1 to 3, characterized in that: In step B, double-gun cutting is used when accidents occur or the machine starts.

5. The steel sheet slab cutting method according to claim 4, characterized by: It also comprises step D maintenance: when replacing the cutting nozzle, a pipe wrench is used to fix the cutting gun body and a wrench is used to remove the cutting nozzle; since the angles and straightness of the cutting gun have been adjusted, the cutting nozzle must not be directly removed by a wrench. In step D, the distance between the cutting nozzle and the blank surface is controlled at 60-80 mm; and the inner diameter deformation of the cutting gun is avoided.