CN118341827A - Intermediate billet treatment method generated in rough rolling process - Google Patents

Abstract

The invention discloses a method for processing an intermediate billet generated in a rough rolling process, which belongs to the technical field of steel rolling and comprises the following steps: s1, returning an intermediate billet generated in one rough rolling pass or an intermediate billet generated in two rough rolling passes to a plate blank library when a production line is interrupted, and cutting the intermediate billet after the intermediate billet is cooled; s2, inputting the cut intermediate blank into a plate blank warehouse system; s3, after the production line is restored, waiting for the quantity of intermediate blanks in the plate blank warehouse system to be greater than M, and executing S4; m is a natural number greater than 5; s4, heating and rough rolling M intermediate blanks; the method comprises the following steps: heating: firstly, mixing and arranging M intermediate slabs and normal slabs so that a vacancy of 6-8M is kept between the intermediate slabs and the normal slabs, and then heating according to each section of temperature system of a heating furnace; rough rolling, namely, rolling the heated intermediate billet for three times; and S5, utilizing the heat preservation cover to preserve heat of the intermediate blank, and carrying out subsequent production procedures.

Description

Intermediate billet treatment method generated in rough rolling process

Technical Field

The invention belongs to the technical field of steel rolling, and particularly relates to a method for processing an intermediate billet generated in a rough rolling procedure.

Background

In the hot continuous rolling process, after a plate blank with the thickness of 230mm is subjected to rough rolling for five or seven passes in a rough rolling process, an intermediate blank with the thickness of 40-50 mm is formed, and the intermediate blank enters a finish rolling process, so that subsequent production is completed. Due to some faults, the rough rolling process is interrupted, and an intermediate billet which is rolled by one pass (thickness 180 mm) and by two passes (thickness 130 mm) and by multiple passes (thickness less than 130 mm) is produced. Because the thickness of the intermediate blanks which are not finished in subsequent production is relatively small, if the intermediate blanks are heated again, uneven deformation can occur, and the initiated uneven deformation is easy to form warping or buckling defects at two ends of the intermediate blanks. When the buckling head is serious, the head of the intermediate billet can collide with the roller way or even flush into the bottom of the roller way; if the warping is serious, the slab possibly collides with an instrument device above the roller way and cannot be bitten into production accidents such as a rolling mill roll gap, so that normal tissue production cannot be realized, and the slab can be cut and returned to the furnace for re-refining for reproduction. Not only reduces the yield of the steel coil, but also increases the process cost for the regeneration of the steel coil. The intermediate blank with multiple passes (thickness less than 130 mm) can only be used as a scrap blank due to the excessively small thickness.

For the first-pass intermediate blank and the second-pass intermediate blank, the heating system of the heating furnace and the reduction system of rough rolling can be improved, the first-pass intermediate blank and the second-pass intermediate blank are reused for rolling again, the consumption is reduced, the comprehensive yield is improved, and the economic loss caused by rough rolling faults is reduced.

Disclosure of Invention

The invention aims to provide a method for processing an intermediate billet generated in a rough rolling process, which aims to solve the problems of processing the intermediate billet generated in one rough rolling process and the intermediate billet generated in two rough rolling processes when a production line is interrupted.

In order to achieve the above object, the present invention provides the following technical solutions:

a method of processing an intermediate billet produced in a rough rolling process, comprising:

s1, returning an intermediate billet generated in one rough rolling pass or an intermediate billet generated in two rough rolling passes to a plate blank library when a production line is interrupted, and cutting the intermediate billet after the intermediate billet is cooled;

s2, inputting the cut intermediate blank into a plate blank warehouse system;

s3, after the production line is restored, waiting for the quantity of intermediate blanks in the plate blank warehouse system to be greater than M, and executing S4; m is a natural number greater than 5;

S4, heating and rough rolling M intermediate blanks; the method comprises the following steps:

heating: firstly, mixing and arranging M intermediate slabs and normal slabs so that a vacancy of 6-8M is kept between the intermediate slabs and the normal slabs, and then heating according to each section of temperature system of a heating furnace;

rough rolling, namely, rolling the heated intermediate billet for three times;

And S5, utilizing the heat preservation cover to preserve heat of the intermediate blank, and carrying out subsequent production procedures.

Preferably, the original thickness of the plate blank is 230mm, the thickness of the intermediate blank of the first rough rolling pass is 180mm, and the thickness of the intermediate blank of the second rough rolling pass is 130mm.

Preferably, the length of the cut is 100mm greater than the width of the water beam.

Preferably, in S2, the planning is performed in accordance with a final thickness specification in the range of 4.75mm to 5.75 mm.

Preferably, the temperature system of each section of the heating furnace is as follows:

Stage(s)	Hearth temperature	At the time of the furnace
			First heating stage	750～1010℃	40min
Second heating stage	1100～1200℃	40min
			Third heating stage	1200～1300℃	50min
Soaking stage	1200～1280℃	30min

。

Preferably, during the heating of S4, the intermediate blank needs to be positioned.

Compared with the prior art, the invention has the beneficial effects that:

By adopting the processing method, when the production line is interrupted, the intermediate blank generated in the first rough rolling pass and the intermediate blank generated in the second rough rolling pass can be reasonably and effectively processed, and furnace return reconstruction is avoided.

Detailed Description

The technical solutions of the embodiments of the present invention will be clearly and completely described in the following in conjunction with the embodiments of the present invention, and all other embodiments obtained by those skilled in the art without making any creative effort based on the embodiments of the present invention are within the protection scope of the present invention.

A method of processing an intermediate billet produced in a rough rolling process, comprising:

S1, returning an intermediate billet generated in one rough rolling pass or an intermediate billet generated in two rough rolling passes to a plate blank library when a production line is interrupted, and cutting the intermediate billet after the intermediate billet is cooled; in this embodiment, the original thickness of the slab may be 230mm, the thickness of the intermediate slab in the first rough rolling pass may be 180mm, and the thickness of the intermediate slab in the second rough rolling pass may be 130mm; cutting the intermediate blank according to the arrangement condition of the water beam of the heating furnace and the dimension of the water beam width plus 100mm, wherein the cutting surface is required to be smooth and free of quality defects such as burrs;

s2, inputting the cut intermediate blank into a plate blank warehouse system;

S3, after the production line is restored, waiting for the quantity of intermediate blanks in the plate blank warehouse system to be greater than M, and executing S4; m is a natural number greater than 5; the method specifically comprises the following steps: the plate blank size is recorded according to the plate blank size after cutting, and planning is carried out according to the thickness specification of the finished product within the range of 4.75 mm-5.75 mm. The intermediate plate blanks of the first pass and the second pass are rolled in a concentrated mode, and are organized according to a minimum of six blocks each time; (in the case of insufficient mill train stock, concentrated tissue production reduces the effect on normal production).

S4, heating and rough rolling M intermediate blanks; the method comprises the following steps:

Heating: firstly, mixing and arranging M intermediate slabs and normal slabs so that a vacancy of 6-8M is kept between the intermediate slabs and the normal slabs, and then heating according to each section of temperature system of a heating furnace; the temperature of each section of the heating furnace is heated according to the lower limit of the temperature (40 ℃ lower than the temperature of each section of the heating furnace for normal slab heating).

Table 1: temperature system of each section of heating furnace

Stage(s)	Hearth temperature	At the time of the furnace
			First heating stage	750～1010℃	40min
Second heating stage	1100～1200℃	40min
			Third heating stage	1200～1300℃	50min
Soaking stage	1200～1280℃	30min

When the intermediate plate blank is heated in the heating furnace, the thickness of the intermediate plate blank is smaller than that of a normal plate blank, and the position of the intermediate plate blank needs to be confirmed and adjusted;

Rough rolling, namely, rolling the heated intermediate billet for three times; the five-pass rolling of rough rolling is adjusted to three-pass rolling, so that the phenomenon that the intermediate slab is seriously buckled and warped in the rolling process due to the fact that the pass rolling reduction is too small is prevented;

And S5, utilizing the heat preservation cover to preserve heat of the intermediate billet, reducing the cooling rate of the intermediate billet, improving the initial rolling temperature of finish rolling, and carrying out subsequent production procedures.

The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the invention.

Claims (6)

1. A method for processing an intermediate billet produced in a rough rolling process, comprising:

s1, returning an intermediate billet generated in one rough rolling pass or an intermediate billet generated in two rough rolling passes to a plate blank library when a production line is interrupted, and cutting the intermediate billet after the intermediate billet is cooled;

s2, inputting the cut intermediate blank into a plate blank warehouse system;

s3, after the production line is restored, waiting for the quantity of intermediate blanks in the plate blank warehouse system to be greater than M, and executing S4; m is a natural number greater than 5;

S4, heating and rough rolling M intermediate blanks; the method comprises the following steps:

heating: firstly, mixing and arranging M intermediate slabs and normal slabs so that a vacancy of 6-8M is kept between the intermediate slabs and the normal slabs, and then heating according to each section of temperature system of a heating furnace;

rough rolling, namely, rolling the heated intermediate billet for three times;

And S5, utilizing the heat preservation cover to preserve heat of the intermediate blank, and carrying out subsequent production procedures.

2. The method of claim 1, wherein the initial thickness of the slab is 230mm, the thickness of the first rough pass intermediate is 180mm, and the thickness of the second rough pass intermediate is 130mm.

3. The method of claim 1, wherein the cut length is 100mm greater than the water beam width.

4. The method for processing an intermediate billet in the rough rolling process according to claim 1, wherein the planning is performed in S2 in accordance with the thickness of the finished product ranging from 4.75mm to 5.75 mm.

5. The method for processing an intermediate billet produced in a rough rolling process according to claim 1, wherein the temperature schedule of each section of the heating furnace is:

Stage(s) Hearth temperature At the time of the furnace First heating stage 750～1010℃ 40min Second heating stage 1100～1200℃ 40min Third heating stage 1200～1300℃ 50min Soaking stage 1200～1280℃ 30min

。

6. The method of claim 1, wherein the intermediate billet is positioned during the heating step S4.