CN103170507A

CN103170507A - Method for preventing surface of strip steel from being scratched when strip steel passes through finishing mill

Info

Publication number: CN103170507A
Application number: CN2013100970412A
Authority: CN
Inventors: 范细忠; 杨旭; 何士国; 张勇
Original assignee: Angang Steel Co Ltd
Current assignee: Angang Steel Co Ltd
Priority date: 2013-03-26
Filing date: 2013-03-26
Publication date: 2013-06-26
Anticipated expiration: 2033-03-26
Also published as: CN103170507B

Abstract

The invention provides a method for preventing surface scratches of strip steel when a finishing mill passes through the air, which enlarges the roll gap of the air-passing rolling mill by quickly opening a hydraulic AGC cylinder of the rolling mill and reducing part of an upper step cushion plate; the angle of the front loop and the rear loop is calibrated again, and the height of the loop for supporting the strip steel is increased; meanwhile, the temperature of the roller is reduced by controlling the input of oil and water, and the 'lubrication' condition between the strip steel and the roller is improved, so that the problem that the roller or a protective plate scratches the surface of the strip steel when the strip steel passes through the air is thoroughly solved, the quality qualification rate of the strip steel is greatly improved, the quality qualification rate of the strip steel is improved from 75% to 95%, and the smooth production is ensured.

Description

A kind of preventing with the method for steel at the empty out-of-date surface tear of finishing mill

Technical field

The invention belongs to the hot-rolled sheet strip steel technology field, particularly a kind of hot-strip that solves is in the method for the empty out-of-date generation surface tear defective of finishing mill.

Background technology

In the hot-strip production process, when situations such as significant trouble appears in finishing mill, and are as abnormal in motor, reductor, gear-box, the damage of AGC hydraulic cylinder or magnetic scale feedback, when causing certain rolling mill normally not drop into, rolled piece just need to be from the empty mistake of this rolling mill.The empty milling train of crossing can not rotate because of motor, and is usually out-of-date at the rolled piece sky so the upper and lower working roll of this milling train of packing into is also to keep not turning state, and the empty roll gap of crossing milling train need to be opened to certain gap values between rollers.

but, out-of-date at certain rolling mill sky, because of rolling working conditions change, before can occurring being with the scratching of steel lower surface and wiping stroke bottom working roll and sky to cross milling train according to former explained hereafter, the phenomenon of rear transition backplate, namely work as certain rolling mill sky out-of-date, before sky is crossed milling train, the rear portion kink all can not drop into, under the impact with steel weight, the empty anterior band of the milling train steel lower surface of crossing will scratching arrive bottom working roll, empty cross the milling train rear portion have the risk of scratching backplate with the steel lower surface, the rolled piece sky is out-of-date in addition, the empty bottom working roll of crossing milling train is in and does not turn state, therefore very easily cause being with steel to occur scratching, hang the defectives such as cured even iron sheet is pressed into, have a strong impact on the surface quality of product, reduce the strip quality qualification rate.

Summary of the invention

Purpose of the present invention is intended to eliminate defects, and then provide a kind of and can effectively solve the empty out-of-date roll of finishing mill or backplate scratches belt steel surface, thereby improve the strip quality qualification rate, guarantee the method that prevents the empty out-of-date surface tear of hot-strip finishing mill of production direct motion.

For reaching this purpose, the technical solution that the present invention takes is:

A kind ofly prevent that its concrete grammar and step are with the method for steel at the empty out-of-date surface tear of finishing mill:

1, sky is crossed the rolling mill AGC hydraulic cylinder and is opened soon, make the empty roll gap of crossing milling train than normal when rolling the roll gap maximum increase by 20～30mm;

2, guaranteeing that in outlet, water discharging board is adjacent under the prerequisite of roll, the upper step pad backing plate of sky being crossed milling train manually removes at least 1, make the empty roll gap of crossing milling train than normal when rolling the roll gap maximum increase by 34～68mm;

3, manually demarcate the empty anterior kink of milling train of crossing by operation screen, anterior kink angle is raised 2 °～3 ° than normal when rolling, make the band steel raise 30～40mm;

4, manually again demarcate the empty milling train rear portion kink of crossing by operation screen, rear portion kink angle is raised 1 °～2 ° than normal when rolling, make the band steel raise 15～30mm;

5, sky is crossed the milling train hot-rolling oil and set and to be adjusted into zero or sky is crossed milling train hot-rolling oil oil pump close, keep the sustained firing of hot rolling cooling water, reduce the temperature of roll gap place roll;

6, when rolling gap, continue manually to cross rolling mill roll to sky and spray cooling water, until manual-lock cooling water again before lower piece steel rolling.

Beneficial effect of the present invention is:

Because the present invention takes finishing mill hydraulic AGC cylinder to open soon and reduces the upper step pad backing plate of part, strengthened the empty roll gap of crossing milling train, reduced the probability of scratching; Again kink angle before and after demarcating has improved kink and has propped height with steel, decrease with steel lower surface scratching roll and backplate may; Spray the cooling water measure by input and the rolling gap of controlling oil, water, reduce roller temperature, improved with " lubricating " condition between steel and roll.Thereby thoroughly solved the problem with the empty out-of-date roll of steel or backplate scuffing belt steel surface, greatly improved the strip quality qualification rate, made with the up-to-standard rate of steel and bring up to more than 95% by 75%, guaranteed carrying out smoothly of production.

The specific embodiment

The present invention prevents with the method for steel at the empty out-of-date surface tear of finishing mill, is mainly by the opening soon and reduce the upper step pad backing plate of part of finishing mill hydraulic AGC cylinder, strengthens the empty roll gap of crossing milling train; Again kink angle before and after demarcating, the raising kink is propped the height with steel; By controlling the input of oil, water, reduce roller temperature simultaneously, improve lubricating condition.Below, cross as example so that the 4th finishing mill (F4 milling train) is empty, the invention will be further described.

1, the AGC hydraulic cylinder of F4 milling train is opened soon, is strengthened the roll gap of F4 milling train, the roll gap that makes the F4 milling train by normal when rolling roll gap maximum 60mm increase to 85mm.

2, guaranteeing that in outlet, water discharging board is adjacent under the prerequisite of roll, the upper step pad backing plate of F4 milling train manually removed 2, again to increase roll gap, the roll gap that makes the F4 milling train by normal when rolling roll gap maximum 60mm increase to 110mm.

3, again manually demarcate kink (L3 kink) between the 3rd finishing mill of F4 milling train (F3 milling train) by operation screen, L3 kink angle is transferred to than normal raise 2.5 ° when rolling, thereby when the L3 kink lifts, can raise 35mm than in the past by the band steel.

4, again manually again demarcate kink (L4 kink) between F4 milling train and the 5th finishing mill (F5 milling train) by operation screen, L4 kink angle is transferred to than normal raise 1.6 ° when rolling, make it when the L4 kink lifts, the band steel can be raised 19mm again.

5, the setting of F4 milling train hot-rolling oil is adjusted into zero (certainly, also can take to close the mode of F4 milling train hot-rolling oil oil pump), namely do not drop into hot-rolling oil, only drop into cooling water, the sustained firing that keeps hot rolling cooling water, thereby the temperature of reduction F4 mill roll-gap place roll makes cooling water play the effect of " lubricating " to the band steel simultaneously, alleviates frictional resistance.

6, when rolling gap, continue manually to spray cooling water to the roll of F4 milling train, breaker roll is lowered the temperature, until manual-lock cooling water again before lower piece steel rolling.

Claims

1. one kind prevents from it is characterized in that with the method for steel at the empty out-of-date surface tear of finishing mill:

(1), AGC hydraulic cylinder that sky is crossed milling train opens soon, make the empty roll gap of crossing milling train than normal when rolling the roll gap maximum increase by 20～30mm;

(2), guaranteeing that in outlet, water discharging board is adjacent under the prerequisite of roll, the upper step pad backing plate of sky being crossed milling train manually removes at least 1, make the empty roll gap of crossing milling train than normal when rolling the roll gap maximum increase by 34～68mm;

(3), manually demarcate the empty anterior kink of milling train of crossing by operation screen, anterior kink angle is raised 2 °～3 ° than normal when rolling, make the band steel raise 30～40mm;

(4), manually again demarcate the empty milling train rear portion kink of crossing by operation screen, rear portion kink angle is raised 1 °～2 ° than normal when rolling, make the band steel raise 15～30mm;

(5), sky is crossed the milling train hot-rolling oil set and to be adjusted into zero or sky is crossed milling train hot-rolling oil oil pump close, keep the sustained firing of hot rolling cooling water, reduce the temperature of roll gap place roll;

(6), when rolling gap, continue manually to cross rolling mill roll to sky and spray cooling water, until manual-lock cooling water again before lower piece steel rolling.