CN102825073A

CN102825073A - Method for controlling oxide scales on surface of moderate thick plate

Info

Publication number: CN102825073A
Application number: CN2012103576907A
Authority: CN
Inventors: 刘源; 王明林; 于峰; 王若钢; 李新玲; 李靖年; 刘浩岩
Original assignee: Angang Steel Co Ltd
Current assignee: Angang Steel Co Ltd
Priority date: 2012-09-25
Filing date: 2012-09-25
Publication date: 2012-12-19

Abstract

The invention provides method for controlling oxide scales on the surface of a moderate thick plate. The method comprises the following steps that: the heating temperature of a plate blank is controlled in the range of 1150 DEG C to 1200 DEG C; the heating temperature of the plate blank placed in a descaling machine is controlled to be lower than or equal to 1150 DEG C, the descaling machine adopts a single-step descaling mode, and the water pressure is from 18 MPa to 22 MPa; the target temperature of a rough rolling treatment for beginning rolling is controlled to be lower than or equal to 1100 DEG C, wherein the descaling is carried out by the rough rolling and the steel conversion in the first step, and the press-down rate of the rough rolling in the last treatment step is controlled in the range of 8% to 11%; and finally the descaling is carried out after finishing the first step of finish rolling. The method has the advantages of simplicity in treatment, convenience in operation, small investment, rapid effect and high production efficiency. In addition, the formation rate of secondary oxide scales on the high-temperature plate blank after being descaled is decreased; the primary oxide scales generated during the heating are removed; the press-in effect of the oxide scales on the surface is lightened obviously; and the surface defect of a rolled steel plate is lowered from original 7% to 1%, thereby improving the surface quality of the steel plate obviously.

Description

A kind of method of controlling the cut deal scale on surface

Technical field

The invention belongs to the steel rolling process technical field, relate in particular to a kind of production method that reduces low-alloy high-strength medium plate scale on surface.

Background technology

High Strength Low Alloy Medium Plate in actual production process owing to receive factor affecting such as chemical composition, rolling and process for cooling; Usually produce surface quality problems such as iron scale is pressed into; Scale on surface be pressed into the presentation quality that not only has a strong impact on steel plate, and totally unfavorable to the serviceability and the military service performance of steel plate.

At present; Domestic iron and steel enterprises is more on the dimensional accuracy and mechanical property that focus on steel plate paid close attention to; Enough attention that shortage is pressed into iron scale, high temperature hot rolling and heating in short-term wait the extensive use of some power-saving technologies in addition, cause this problem never to be solved completely; Become one of factor of restriction product structure upgrading, perplexing each Heavy Plate Production producer all the time.

Both at home and abroad manufacturer existingly adopts the control heating atmosphere, changes over method such as branch design and solve this type of problem, but all owing to operating difficulties, process is wayward, and production efficiency is low, and effect is also undesirable, thereby in application, is restricted.

Summary of the invention

The present invention is intended to provide a kind of technology simple to the series of the low-alloy high-strength among GB/T1591-2008 cut deal, is convenient to operation, can effectively reduce and remove the cut deal scale on surface, improves the production method of rolling back cut deal surface quality.

For this reason, the technical solution that the present invention taked is:

A kind of method of controlling the cut deal scale on surface, its concrete grammar and step are:

1, slab heating temperature is controlled at 1150-1200 ℃;

2, descaling mill board briquette≤1150 ℃ are gone in control, and descaling mill adopts the single pass de-scaling, and hydraulic pressure is 18-22MPa;

3, roughing open rolling target temperature≤1100 ℃, steel (being that steel billet is turned round to rolling direction in length and breadth) the first passage de-scaling is changeed in the roughing first passage de-scaling, and last percentage pass reduction of roughing is controlled at 8%-11%;

4, carry out de-scaling after finish rolling first passage.

Beneficial effect of the present invention is:

The present invention can slow down the formation speed of high temperature slab secondary oxidation iron sheet after the de-scaling; The once oxidation iron sheet that produces when removing heating; Prevent in a stage scale on surface to be pressed into the iron scale perk phenomenon of treating that warm process light plate surface transition oxidation occurs after rolling significantly to alleviate, add up through The field; Roll back Surface Defects in Steel Plate ratio and be reduced to 1% by original 7%, plate surface quality be improved significantly.Simultaneously, it is simple, easy to operate that the present invention also has technology, small investment, instant effect, and characteristics such as production efficiency height can be widely used in the production of cut deal.

The specific embodiment

Embodiment 1:

The technological process of production is heating-de-scaling-controlled rolling-control cooling-aligning-cutting-warehouse-in.Rolling steel grade is Q345B.

The concrete grammar and the step of control cut deal scale on surface are:

1, slab heating temperature is controlled at 1150 ℃, prevents the too high secondary oxidation iron sheet that after de-scaling, generates rapidly of board briquette.

2, go into the descaling mill board briquette and be controlled at 1100 ℃, de-scaling hydraulic pressure is 19MPa, and descaling mill adopts the single pass de-scaling, so that remove the once oxidation iron sheet that steel slab surface generates when heating.

3, rationally control roughing temperature and de-scaling passage, 1050 ℃ of roughing open rolling target temperatures prevent that the iron scale perk from appearring in slab when a stage rolling end.The roughing first passage de-scaling is changeed the steel first passage de-scaling, all the other all not de-scalings of passage.Control roughing last percentage pass reduction is 8%, to guarantee the glacing flatness of plate shape, avoids occurring the nose phenomenon and influences phosphor-removing effect.

4, carry out de-scaling after finish rolling first passage; Remove the iron scale of treating that thermophase surface generates, all the other all not de-scalings of passage, the anti-stage here causes de-scaling incomplete owing to steel plate composition or microstructure segregation; Cause iron scale to be pressed into surface of steel plate, guarantee to roll the fineness of back surface of steel plate.

All the other adopt common process.

Embodiment 2:

The technological process of production is heating-de-scaling-controlled rolling-control cooling-aligning-cutting-warehouse-in.Rolling steel grade is Q460C.

The concrete grammar and the step of control cut deal scale on surface are:

1, slab heating temperature is controlled at 1200 ℃, prevents the too high secondary oxidation iron sheet that after de-scaling, generates rapidly of board briquette.

2, go into the descaling mill board briquette and be controlled at 1150 ℃, de-scaling hydraulic pressure is 22MPa, and descaling mill adopts the single pass de-scaling, so that remove the once oxidation iron sheet that steel slab surface generates when heating.

3, rationally control roughing temperature and de-scaling passage, 1090 ℃ of roughing open rolling target temperatures prevent that the iron scale perk from appearring in slab when a stage rolling end.The roughing first passage de-scaling is changeed the steel first passage de-scaling, all the other all not de-scalings of passage.Control roughing last percentage pass reduction is 11%, to guarantee the glacing flatness of plate shape, avoids occurring the nose phenomenon and influences phosphor-removing effect.

All the other adopt common process.

Claims

1. a method of controlling the cut deal scale on surface is characterized in that, concrete grammar and step are:

(1), slab heating temperature is controlled at 1150-1200 ℃;

(2), control goes into descaling mill board briquette≤1150 ℃, descaling mill adopts the single pass de-scaling, hydraulic pressure is 18-22MPa;

(3), roughing open rolling target temperature≤1100 ℃, the steel first passage de-scaling is changeed in the roughing first passage de-scaling, last percentage pass reduction of roughing is controlled at 8%-11%;

(4), carry out de-scaling after finish rolling first passage.