A method for improving the production control of head and tail defects of a bar

Abstract

The application discloses a production control method for improving bad material at the head and tail of a rod, which comprises the following steps: 1) water descaling delay setting, 2) increasing the speed of a medium-rolling rolling mill and rolling mill cooling water, and 3) controlling the flow of a water tank, and avoiding the head and tail of an intermediate blank. The application can reduce the length of the bad material at the head and tail by controlling the descaling pump delay, increasing the speed of the medium-rolling rolling mill and avoiding the head and tail of the water tank, thereby greatly improving the yield and surface quality of the material and reducing production failures.

Description

TECHNICAL FIELD

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

[0002] At present, the bar rolling line in China has realized continuous rolling production. Due to the inevitable defects of the billet during steelmaking, cracks and folding defects are easily generated at the head and tail of the intermediate billet during the rolling process, which are usually called bad material. The bad material is cut clean by the flying shear lengthening shear during the production process, which greatly affects the yield rate. If the bad material is not cut clean, it will affect the biting of the rolling mill, cause the billet head to run out of the mill outlet and cause equipment failure during the production process, and also affect the surface quality and mechanical properties of the finished product. SUMMARY

[0003] The present application provides a production control method for improving bad material at the head and tail of a bar, which controls the delay of the descaling pump, increases the speed of the intermediate rolling mill and avoids the head and tail of the water tank, so as to reduce the length of the head and tail bad material, which has great benefits for improving the yield rate and surface quality and reducing production failure.

[0004] Technical scheme: The production control method for improving bad material at the head and tail of a bar, characterized in that it comprises three steps: step 1) water descaling delay setting, step 2) increasing the speed of the intermediate rolling mill and the cooling water of the rolling mill, and step 3) controlling the flow of the water tank through the photoelectric tube delay, and avoiding the head and tail of the intermediate billet.

[0005] In 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 of the billet head is increased, and the scale on the end of the billet and the impurities on the surface of the billet are completely removed.

[0006] In step 2) increasing the speed of the intermediate rolling mill and the cooling water of the rolling mill, the speed of the rolling mill is increased when the billet head enters the intermediate rolling mill, and the cooling water flow rate of the rolling mill gap is increased, so as to avoid folding of the intermediate billet head during the rolling process due to plastic extension.

[0007] In step 3) controlling the flow of the water tank and avoiding the head and tail of the intermediate billet, the flow of the water tank is controlled by the photoelectric tube delay before the intermediate billet enters the water tank, so as to avoid the extension of the bad material at the head and tail of the intermediate billet during the rolling process due to the low temperature of the head and tail.

[0008] The intermediate blank head enters the hole type of the middle rolling A frame rolling mill, the line speed of the middle rolling 4 frame rolling mill is sequentially increased, the cooling water pressure is increased to 0.55MPa-0.60MPa, the head tail oxidation of the intermediate blank is reduced, 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, the speed of the 6 frame is 0.45m / s, so that the head blank between the A-6 frame rolling mills is in a tension state, the folding of the intermediate blank head in the plastic deformation extension process during the rolling process is avoided, the intermediate blank is cut by the 6 frame, and the cutting length is reduced.

[0009] In the step 3), before the intermediate blank head tail enters the water tank, the water tank booster pump is closed, the intermediate blank head tail is empty in the water tank, and after the water tank, the water tank booster pump is opened again.

[0010] Beneficial effects: Compared with the prior art, the present application has the following remarkable advantages: the present application improves the head tail bad material problem of the rod in the rolling process. By controlling the delay of the descaling pump, increasing the speed of the middle rolling mill and avoiding the head tail of the water tank, the length of the head tail bad material is reduced, which is of great benefit to improving the yield and surface quality and reducing production failures. The length of the intermediate blank is reduced, the cutting length of the flying shear is reduced by 66%, the surface quality and mechanical properties are improved, and the production failure caused by the head bad material is reduced. DETAILED DESCRIPTION

[0011] The technical solutions of the present application will be further described below in combination with specific embodiments.

[0012] The production control method for improving the head tail bad material of the rod comprises:

[0013] Step 1) water descaling delay setting: the water pressure is turned on 1.8s in advance before the blank enters the descaling equipment, so that the water descaling pressure of the blank head is increased, and the scale on the end of the blank and the impurities on the surface of the blank are completely removed

[0014] Step 2) increase the speed of the middle rolling mill and the cooling water of the roller: the speed of the middle rolling mill is increased when the blank head enters the middle rolling mill, and the cooling water flow rate of the roller gap is increased, so that the folding of the intermediate blank head in the plastic extension during the rolling process is avoided.

[0015] After the intermediate billet head enters the hole pattern of the intermediate rolling A frame rolling mill, the wire speed of the intermediate rolling 4 frame rolling mill is increased in turn, and the cooling water pressure is increased to 0.55MPa-0.60MPa, so as 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, the folding of the intermediate billet head in the plastic deformation extension process during the rolling process is avoided, the intermediate billet is cut at the head and tail by the 6 frame, and the length of the head and tail cutting is reduced.

[0016] Step 3) Control the water tank flow, and avoid the head and tail of the intermediate billet: before the intermediate billet enters the water tank, the water tank booster pump is closed, so that the head and tail of the intermediate billet are empty in the water tank, and after the water tank, the water tank booster pump is opened again; the head and tail are avoided by delaying the water tank flow through the photoelectric tube, so as to avoid the extension of the head and tail in the rolling process of the finishing rolling mill due to the low temperature of the head and tail of the intermediate billet.

[0017] By adjusting the descaling pump delay, the intermediate rolling mill speed and the water tank head and tail avoidance, the length of the head and tail of the intermediate billet is reduced, and the cutting length of the intermediate billet is reduced from 350mm to 120mm; it is of great benefit to improve the finished product yield, surface quality and reduce the production failure caused by the head and tail.

[0018] The application improves the head and tail problem of the rod in the rolling process. By controlling the descaling pump delay, increasing the intermediate rolling mill speed and avoiding the water tank head and tail, the length of the head and tail is reduced, which is of great benefit to improve the yield and surface quality and reduce the production failure. The length of the intermediate billet is reduced, the length of the flying shear cutting head and tail is reduced by 66%; the surface quality and mechanical properties are improved; the production failure caused by the head and tail is reduced.

Claims

1. A method of improving the production control of head and tail off material from a bar, characterized by: The method comprises steps 1) water descaling delay setting, 2) increasing the speed of the intermediate rolling mill and the roller cooling water, and 3) controlling the water tank flow through a photoelectric tube delay, and avoiding the intermediate blank head and tail. The step 1) water descaling delay setting: the water pressure is turned on 1.8 s in advance before the blank enters the descaling equipment, so that the water descaling pressure of the blank head is increased, and the scale on the blank end and the impurities on the blank surface are removed. The step 2) increasing the speed of the intermediate rolling mill and the roller cooling water: the speed of the intermediate rolling mill is increased when the blank head enters the intermediate rolling mill, and the cooling water flow rate of the rolling mill gap is increased, so that the intermediate blank head is prevented from being folded due to plastic extension during the rolling process; after the intermediate blank head enters the hole type of the intermediate rolling mill A frame, the wire speed of the intermediate rolling mill 4 frame is sequentially increased, the cooling water pressure is increased to 0.55-0.60 MPa, and the oxidation of the intermediate blank head and tail is reduced; the speed of the A frame is 0.22 m / s, the speed of the B frame is 0.28 m / s, the speed of the 5 frame is 0.36 m / s, and the speed of the 6 frame is 0.45 m / s, so that the blank head between the A-6 frames is in a tension state, the intermediate blank head is prevented from being folded due to plastic deformation extension during the rolling process, the intermediate blank is cut at the head and tail after the 6 frame, and the cutting length of the head and tail is reduced. The step 3) controlling the water tank flow, and avoiding the intermediate blank head and tail: before the intermediate blank enters the water tank, the water tank flow is controlled through a photoelectric tube delay to avoid the head and tail of the intermediate blank, so that the head and tail of the intermediate blank are prevented from being damaged and extended during the rolling process of the finishing rolling mill group; before the intermediate blank head and tail enter the water tank, the water tank booster pump is closed, the intermediate blank head and tail are made to be empty in the water tank through a photoelectric tube delay, and after the intermediate blank head and tail exit the water tank, the water tank booster pump is turned on again.