CN117862249A

CN117862249A - Method for calculating temperature drop of steel plate in steckel mill rolling process

Info

Publication number: CN117862249A
Application number: CN202410049825.6A
Authority: CN
Inventors: 杜宁宇; 范锦龙
Original assignee: Wisdri Engineering and Research Incorporation Ltd
Current assignee: Wisdri Engineering and Research Incorporation Ltd
Priority date: 2024-01-12
Filing date: 2024-01-12
Publication date: 2024-04-12

Abstract

The invention relates to the technical field of steel processing, in particular to a steel plate temperature drop calculation method in a steckel mill rolling process, which comprises the following steps: according to an empirical formulaCalculating the temperature drop delta T of the steel plate in the ith pass _i Wherein k is an empirical coefficient related to the steel sheet material, H is the distance between two coiling furnaces, v _i A rolling speed preset for the ith pass, h _i T is the average value of the thickness before rolling and the thickness after rolling of the ith pass steel plate _i‑1 The average temperature of the steel plate after the steel plate is subjected to the i-1 th pass rolling. Compared with the prior art, the method can estimate the temperature of the intermediate billet of the steckel rolling pass more conveniently and efficiently, reduce the difficulty of rolling schedule calculation, and provide convenience for the early design of factories.

Description

Method for calculating temperature drop of steel plate in steckel mill rolling process

Technical Field

The disclosure relates to the technical field of steel processing, in particular to a steel plate temperature drop calculation method in a steckel mill rolling process.

Background

In a hot rolling production line, the temperature of a billet is a key parameter set in a rolling process, and is also an important basis for calculating rolling force and motor torque. The rolled piece on the rolling line can only obtain the surface temperature of the billet through the thermometer, and the core temperature detection can not be realized. In current hot rolling line control, the core temperature is typically calculated from the measured surface temperature. When the front-stage design of the medium plate workshop is performed, the approximate calculation of the temperatures of each pass of rolling is required to be completed under the condition that the tapping temperature of a continuous casting blank is known only.

In a steckel rolling line, rolling is required to be performed by a coiling furnace to reduce the temperature drop of an intermediate billet when rolling a thin product. The temperature is calculated in the flat rolling pass before rolling and is the same as that of conventional medium plate rolling, the existing temperature drop approximate calculation formula can be adopted, and the temperature drop calculation in the rolling pass generally adopts a finite element method to carry out simulation calculation on a blank temperature field at present. Therefore, a new method for calculating the temperature drop of the steel plate in the rolling process of the steckel mill is needed to estimate the temperature of the steckel mill rolling pass intermediate billet more conveniently and efficiently, reduce the difficulty of rolling schedule calculation and provide convenience for the early design of factories.

Disclosure of Invention

The invention aims to provide a novel steel plate temperature drop calculation method in the steckel mill rolling process, so that the temperature of a steckel mill rolling pass intermediate blank can be estimated more conveniently and efficiently, the difficulty of rolling schedule calculation is reduced, and convenience is provided for factory early design.

Specifically, the technical scheme of the present disclosure is:

a steel plate temperature drop calculation method in a steckel mill rolling process comprises the following steps:

s1: according to an empirical formulaCalculating the temperature drop delta T of the steel plate in the ith pass _i Wherein k is an empirical coefficient related to the steel sheet material, H is the distance between two coiling furnaces, v _i A rolling speed preset for the ith pass, h _i T is the average value of the thickness before rolling and the thickness after rolling of the ith pass steel plate _i-1 The average temperature of the steel plate after the steel plate is subjected to the i-1 th pass rolling.

In one embodiment, before step S1, the method further includes: the empirical coefficient k is obtained from a pre-established database.

In one embodiment, before step S1, the method further includes: obtaining a preset pre-rolling thickness value and a preset post-rolling thickness value of the ith-pass steel plate, and calculating to obtain h _i 。

In one embodiment, H is in m, v _i In m/s, h _i In mm, T _i-1 Is in units of K.

The beneficial technical effects of the present disclosure are:

the method can estimate the temperature of the intermediate billet of the steckel rolling pass more conveniently and efficiently than the prior art, reduces the difficulty of rolling schedule calculation, and provides convenience for the early design of factories.

Drawings

FIG. 1 is a schematic view of a steckel mill.

Detailed Description

The disclosure is further described in detail below with reference to the drawings and specific examples.

Referring to fig. 1, the rolling process of a steel sheet (not shown) is to perform a number of flat rolling first, i.e., the steel sheet is rolled several times back and forth through the rolling mill 1, but does not enter the coiling furnace 2a and the coiling furnace 2b at both sides of the rolling mill 1. After a plurality of flat rolling, the steel plate reaches a thinner thickness, and then the steel plate is rolled for a plurality of times, namely the steel plate is rolled back and forth through the rolling mill 1 for a plurality of times, and is rolled into a coiling furnace at the corresponding side after being rolled through the rolling mill 1 each time.

The purpose of the present disclosure is to provide a simple calculation method for calculating the temperature drop of a steel plate during rolling. Verified that the temperature drop of the steel plate in the rolling process approximately meets the empirical formula ΔT _i For the temperature drop of the steel plate in the ith pass, k is an empirical coefficient related to the steel plate material, H is the distance between two coiling furnaces, v _i For the ith passA preset rolling speed h _i T is the average value of the thickness before rolling and the thickness after rolling of the ith pass steel plate _i-1 The average temperature of the steel sheet after the i-1 th pass rolling (i.e., before the i-th pass rolling) is given to the steel sheet. Since there are several passes of flat rolling before rolling, i is typically an integer greater than 1.

For easy calculation, H is given in m (meters), v _i In m/s (meters/second), h _i In mm (millimeters), T _i-1 In K (Kelvin), K being in mm/(sxK) ³ ) The value range of k is 5-30. In other embodiments, the above parameters may also be other units, e.g., H may be in mm, T _i-1 Can be in units of C, h _i The unit of (c) may be m, and a person skilled in the art may adjust the formula according to the variation of the unit of parameter to obtain a formula substantially equivalent to the above-mentioned empirical formula.

The empirical coefficient k is related to the steel plate material, and the empirical coefficients k of the steel plates of different materials are different, for example, the k value of 304 stainless steel is 13, and the k value of AH36 ship plate steel is 19. Before the temperature drop is calculated by using the above empirical formula, the empirical coefficient k of the steel plate needs to be known. The empirical coefficient k is obtained by H, v in the rolling process _i 、h _i 、T _i Data are fitted to obtain experience coefficients k of corresponding steel plate materials, the experience coefficients k are input into a database, the names of the steel plate materials in the database correspond to the experience coefficients k one by one, and the experience coefficients k are conveniently obtained according to the material names of rolled steel plates to calculate temperature drop delta T _i . Wherein, the temperature data T of the steel plate after each pass of rolling is obtained _i The method comprises measuring temperatures at multiple different positions on the steel plate after each pass of rolling, taking average value as average temperature T of the steel plate after the pass of rolling _i ，ΔT _i ＝T _i -T _i-1 。

The thickness before rolling and the thickness after rolling of the ith pass steel plate are preset, namely the rolling thickness of each pass of rolling mill 1 is preset, and the temperature drop delta T is calculated _i The preset rolling thickness of the ith pass and the preset rolling thickness of the ith-1 pass are read before, and the average value is calculated to obtain h _i . Rolling speed v of each pass mill 1 _i Is also preset.

The following are two groups of the above empirical formulasThe temperature drop data obtained by calculation is verified to be basically consistent with the actual data, and the validity of the empirical formula of the disclosure can be proved. Wherein Z is _i ＝H/v _i In s, deltaT _i 、T _i The units of (2) are changed from K to C.

When the first group of data is to roll 304 stainless steel, the thickness of a continuous casting blank is 220mm when the thickness of the product is 4.6mm, and the rolling schedule sets 7-pass flat rolling and 5-pass steckel rolling. The line layout H is about 12m, the k value is 13, and the above empirical formula is adoptedThe approximate calculation was performed and the temperature drop calculation results are shown in table 1.

Table 1304 stainless steel temperature drop calculation results

When the second group of data is to roll AH36 ship plate steel, the thickness of a continuous casting blank is selected to be 150mm when the thickness of the product is 8mm, and the rolling schedule sets 6-pass flat rolling and 5-pass steckel rolling. The line layout H is about 15m, the k value is 19, and the above empirical formula is adoptedThe approximate calculation was performed and the temperature drop calculation results are shown in table 2.

Table 2 results of calculation of AH36 ship plate steel temperature drop

The foregoing description is only of the preferred embodiments of the present disclosure and is not intended to limit the present disclosure. It should be noted that any modifications, equivalent substitutions, improvements, etc. made by those skilled in the art after reading the present specification, which are within the spirit and principles of the present disclosure, are intended to be included within the scope of the present disclosure.

Claims

1. The method for calculating the temperature drop of the steel plate in the rolling process of the steckel mill is characterized by comprising the following steps of:

2. The method for calculating the temperature drop of a steel plate in a steckel mill rolling process according to claim 1, further comprising, before step S1: the empirical coefficient k is obtained from a pre-established database.

3. The method for calculating the temperature drop of a steel plate in a steckel mill rolling process according to claim 1, further comprising, before step S1: obtaining a preset pre-rolling thickness value and a preset post-rolling thickness value of the ith-pass steel plate, and calculating to obtain h _i 。

4. The method for calculating the temperature drop of the steel plate in the rolling process of the steckel mill according to claim 1, wherein the method comprises the following steps: h has the unit of m, v _i In m/s, h _i In mm, T _i-1 Is in units of K.