Production control method for improving bar head and tail blank

Abstract

The invention discloses a production control method for improving bar head and tail bad materials. The production control method comprises the following three steps: (1) setting water descaling delay; (2) increasing the speed of an intermediate rolling mill and cooling water of a roller; and (3) controlling the flow of a water tank and avoiding the head and the tail of an intermediate billet. According to the method, the length of the head and tail bad materials is reduced by controlling the delay of the descaling pump, increasing the speed of the intermediate rolling mill and avoiding the head and the tail of the water tank, and the method has great benefits for improving the yield and the surface quality and reducing production faults.

Description

Technical Field

[0001] The invention relates to the field of steel, and in particular to a production control method for improving the bad material at the head and tail of a bar. Background Art

[0002] At present, domestic bar rolling lines have all achieved continuous rolling production. Due to the inevitable defects of billet during steelmaking, cracks, folds and other defects are easily generated at the head and tail of the intermediate billet during steel rolling. Such defects are usually called bad billets. In the production process, the bad billets will be sheared cleanly by extending the shearing by flying shears, which has a great impact on the yield rate. If the bad billets are not sheared cleanly, it will affect the bite of the rolling mill, causing steel to slip at the exit of the billet head stamping mill and equipment failure during the production process, and will also affect the surface quality and mechanical properties of the finished product. Summary of the invention

[0003] Purpose of the invention: In view of the shortcomings and defects of the prior art, the present invention provides a production control method for improving the bad material at the head and tail of the bar. By controlling the delay of the descaling pump, increasing the speed of the intermediate rolling mill and avoiding the head and tail of the water tank, the length of the bad material at the head and tail can be reduced, which has great benefits for improving the yield rate and surface quality and reducing production failures.

[0004] Technical solution: The present invention provides a production control method for improving the bad material at the head and tail of the bar, which is characterized by comprising the following three steps: step 1) setting the water descaling delay, step 2) increasing the speed of the intermediate rolling mill and the cooling water of the rolls, and step 3) controlling the water tank flow rate through a photoelectric tube delay to avoid the head and tail of the intermediate billet.

[0005] Among them, the step 1) water descaling delay setting: the water pressure is turned on 1.8s in advance before the billet enters the descaling equipment, so that the water descaling pressure at the head of the billet is increased, and the iron oxide scale at the end of the billet and impurities on the surface of the billet are cleaned.

[0006] Among them, the step 2) increases the speed of the intermediate rolling mill and the cooling water of the rolls: the mill speed is increased when the billet head enters the intermediate rolling mill, and the cooling water flow rate of the mill roll gap is increased to avoid folding of the intermediate billet head due to plastic extension during the rolling process.

[0007] Among them, the step 3) controls the water tank flow rate to avoid the head and tail of the intermediate billet: before the intermediate billet enters the water tank, the water tank flow rate is controlled by delaying the photoelectric tube to avoid the head and tail, so as to avoid the low temperature of the head and tail of the intermediate billet, which may cause the head and tail to extend due to bad material during the rolling process of the finishing mill.

[0008] Among them, in the step 2), after the head of the intermediate billet enters the hole type of the intermediate rolling A frame rolling mill, the linear speed of the intermediate rolling 4 frames rolling mill is increased in sequence, and the cooling water pressure is increased to 0.55MPa-0.60MPa to reduce the oxidation of the head and tail of the intermediate billet; the speed of the A frame is 0.22m / s, the speed of the B frame is 0.28m / s, the speed of the 5 frame is 0.36m / s, and the speed of the 6 frame is 0.45m / s, so that the head billet between the A-6 frames rolling mills is in a tension state to avoid folding of the head of the intermediate billet during the rolling process due to plastic deformation and extension. The 6 frame comes out to cut the head and tail of the intermediate billet, reducing the length of the cut head and tail.

[0009] Among them, in the step 3), before the head and tail of the intermediate billet enter the water tank, the water tank booster pump is turned off to allow the head and tail of the intermediate billet to pass through the water tank. After the intermediate billet exits the water tank, the water tank booster pump is turned on again.

[0010] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: The present invention improves the problem of head and tail bad material during the rolling process of the bar. By controlling the delay of the descaling pump, increasing the speed of the intermediate rolling mill and avoiding the head and tail of the water tank, the length of the head and tail bad material can be reduced, which has great benefits for improving the yield rate and surface quality and reducing production failures. The length of the intermediate billet is reduced, and the length of the head and tail of the flying shear is reduced by 66%; the surface quality and mechanical properties are improved; and production failures caused by head bad material are reduced. DETAILED DESCRIPTION

[0011] The technical solution of the present invention is further described below in conjunction with specific implementation methods.

[0012] The production control method for improving the head and tail defective material of the bar material of the present invention comprises:

[0013] Step 1) Delay setting of water descaling: The water pressure is turned on 1.8s before the billet enters the descaling equipment, so that the water descaling pressure at the head of the billet is increased, and the iron oxide at the end of the billet and the impurities on the surface of the billet are cleaned.

[0014] Step 2) Increase the speed of the intermediate rolling mill and the cooling water of the rolls: Increase the mill speed when the billet head enters the intermediate rolling mill, and at the same time increase the cooling water flow rate of the mill roll gap to avoid folding of the intermediate billet head due to plastic extension during the rolling process.

[0015] After the head of the intermediate billet enters the hole pattern of the intermediate rolling mill A, the linear speeds of the 4 intermediate rolling mills are increased in sequence, and the cooling water pressure is increased to 0.55MPa-0.60MPa to reduce the oxidation of the head and tail of the intermediate billet; the speed of the A frame is 0.22m / s, the speed of the B frame is 0.28m / s, the speed of the 5 frame is 0.36m / s, and the speed of the 6 frame is 0.45m / s, so that the head billet between the A-6 rolling mills is in a tension state to avoid folding of the head of the intermediate billet due to plastic deformation and extension during the rolling process. The 6 frame comes out to cut the head and tail of the intermediate billet, reducing the length of the cut head and tail.

[0016] Step 3) Control the water tank flow to avoid the head and tail of the intermediate billet: Before the intermediate billet enters the water tank, turn off the water tank booster pump to allow the head and tail of the intermediate billet to pass through the water tank. After it exits the water tank, turn on the water tank booster pump again; control the water tank flow by delaying the photoelectric tube to avoid the head and tail, so as to avoid the low temperature of the head and tail of the intermediate billet, which may cause the head and tail to extend during the rolling process of the finishing mill.

[0017] The present invention reduces the length of bad material at the head and tail of the intermediate billet by adjusting the delay of the descaling pump, speeding up the intermediate rolling mill and avoiding the head and tail of the water tank, so that the cutting length of the intermediate billet is reduced from 350mm to 120mm. It is of great benefit to improving the finished product yield and surface quality and reducing production failures caused by bad material at the head.

[0018] The present invention improves the problem of head and tail bad material during the rolling process of the bar. By controlling the time delay of the descaling pump, increasing the speed of the intermediate rolling mill and avoiding the head and tail of the water tank, the length of the head and tail bad material is reduced, which has great benefits for improving the yield rate and surface quality and reducing production failures. The length of the intermediate billet is reduced, and the length of the head and tail of the flying shear is reduced by 66%; the surface quality and mechanical properties are improved; and the production failures caused by head bad material are reduced.

Claims

1. A production control method for improving the head and tail defects of bar materials, characterized in that: The method comprises the following three steps: 1) setting a water descaling delay, 2) increasing the speed of the intermediate rolling mill and the cooling water of the rolling rolls, and 3) controlling the flow of the water tank by delaying a photoelectric tube and avoiding the head and tail of the intermediate billet.

2. The production control method for improving the head and tail defect of the bar according to claim 1 is characterized by: The step 1) water descaling delay setting: the water pressure is turned on 1.8s before the billet enters the descaling equipment, so that the water descaling pressure at the head of the billet is increased, and the iron oxide scale at the end of the billet and impurities on the surface of the billet are cleaned.

3. The production control method for improving the head and tail defect of the bar according to claim 2 is characterized in that: The step 2) increases the speed of the intermediate rolling mill and the cooling water of the rolls: when the billet head enters the intermediate rolling mill, the mill speed is increased, and at the same time, the cooling water flow rate of the mill roll gap is increased to avoid folding of the intermediate billet head due to plastic extension during the rolling process.

4. The production control method for improving the head and tail defective material of the bar according to claim 3 is characterized in that: The step 3) controls the water tank flow to avoid the head and tail of the intermediate billet: before the intermediate billet enters the water tank, the water tank flow is controlled by delaying the photoelectric tube to avoid the head and tail, so as to avoid the low temperature of the head and tail of the intermediate billet, which may cause the head and tail to extend due to bad material during the rolling process of the finishing mill.

5. The production control method for improving the head and tail defect of the bar according to claim 3 is characterized in that: In the step 2), after the head of the intermediate billet enters the hole type of the intermediate rolling mill A, the linear speeds of the intermediate rolling mills 4 are increased in sequence, and the cooling water pressure is increased to 0.55MPa-0.60MPa to reduce the oxidation of the head and tail of the intermediate billet; the speed of the A frame is 0.22m / s, the speed of the B frame is 0.28m / s, the speed of the 5 frame is 0.36m / s, and the speed of the 6 frame is 0.45m / s, so that the head billet between the A-6 frames is in a tension state to avoid folding of the head of the intermediate billet during the rolling process due to plastic deformation and extension. The 6 frame comes out to cut the head and tail of the intermediate billet, reducing the length of the cut head and tail.

6. The production control method for improving the head and tail defect of the bar according to claim 4 is characterized in that: In the step 3), before the head and tail of the intermediate billet enter the water tank, the water tank booster pump is turned off, and the head and tail of the intermediate billet are allowed to pass through the water tank through a delay of the photoelectric tube. After the intermediate billet exits the water tank, the water tank booster pump is turned on again.