SU1258546A1 - Method of producing small-section rolled stock - Google Patents

Abstract

The method of production of small-section rolled steel was related to the field of wide-angle metallurgy, namely, the processing of bar stock. The aim of the invention is to improve the uniformity of the mechanical properties of the metal in terms of the initial and final sections of the car. The production method involves successively hot production (heat, heat treatment from rolling heating in a sectioned cooling device, in which the cooling intensity is regulated taking into account tailor heating (I split, and winding the peal into the ikxBiiM coil is that the flow rate change from zero to a predetermined value in accordance with the standard Q ,, Q / t ifli - (t - t) 1FN BXipffe initial section of the roll in the initial device n from the specified value <en1 to cool: in response with the dependence QQ / - - ii-t) at the output of the end about the roll section, where Q to Qk is the flow rate of the coolant; Q is the set value for the coolant flow rate; t is the current time; t and t is the start time of the adjustment process at the entrance of the initial section of the roll at the end output, respectively; -the adjustment time; t " K t / V, where K is a coefficient i depending on the type of cooling device, its size, type of cooled stat and the number of rolled cross sections; t is the section length of the cooling device; V - the rate of change ("roll. I l., 1 tab. (O: n X): l E)

Description

The invention relates to ferrous metallurgy, in particular to the processing of bar stock, and can be used in the manufacture of small section steel and rolled wire supplied in coils.

The purpose of the invention is to improve the uniformity of the mechanical properties of the metal along the length of the initial and final parts of the roll.

The drawing shows the functional scheme of the proposed method.

The method of producing small section rolled steel can be realized on a shovel of a continuous small section mill equipped with a device for heat treatment in a stream and coilers, as well as on continuous wire mills.

Using the input data source device 1, information about the brand of rolled steel, the cross-sectional area of rolling, as well as the magnitude of i and K are entered into the control unit 2. After leaving the last stand 3 of the hot rolling mill, the bar is fed A cooling device. The rolling speed sensor 5 anosites the speed information into the control logic device 2, and the photo relay 6 and the temperature sensor 7 record the moment of roll out before the cooling device and its temperature. On the basis of these duns, the control logic device 2, taking into account the transport delay, is controlled by the given dependencies of the flow rate controller 8 of the cooler supplied to the pine station 9 to the control section 10 of its device cooling at the end sections roll. For cooling the device, the sensor P monitors the temperature of the extruding roll, and the latter winds up into a coil on the winder $ 2. The regulator 8 can be made in the form of a valve with a corresponding characteristic

The given dependences of the change in the flow rate of the coolers when passing through the installation of the initial and final sections of the roll are selected based on the temperature distribution along the length of the indicated section. Studies have shown tTo such a distribution

with sufficient accuracy is approximated by the equations

, (t - t, +7 f

dp of the initial section and

t + -

st th

. (t tj

for the final

where T c and T is the current temperature value;

T. - rolled tempers;

TQ is the temperature of the car In its middle part;

t is the current time;

tjj - entry time

the initial part of the rental in the section of the cooling device;

t is the moment of exit

the final section is; kata from the section;

with - the time course of the transition process in the section

./, .. t

t K -,

V

where K is a coefficient that depends on

the type of cooling device, its size, grade of cooled steel and the cross-sectional area of the rolled metal; {- dpina cooling section

devices;

V is the rate of movement of the roll. The above equations are obtained by constant pressure of the chiller in the heat treatment unit when the end sections of the car are processed.

If the corresponding flow rate of the cooler is changed in one or several installation sections during the passage of the initial and final sections of the roll, the overcooling of these sections in the remaining sections is compensated, therefore, the temperature and mechanical properties distribution along the length approach the uniform one at the set values. Number of sections, working

by the specified principle depends on the cooling capacity of each section and on the total number of sections in the heat treatment unit.

Method for the production of mepkosoritogo rolled and rolled wire tested in the production of rolled 014-31 mm from carbon steel grades on a small section mill 250-6 "

In order to reproduce a known production method, a chiller is supplied to the cooling line in advance, and then rental is directed there.

According to the technological design, in the production of a rolled stock at the specified mill, the cooler is supplied to the cooling line 7 seconds after the hire leaves the last stand, which ensures reliable capture of the roll by the reel drum, but forms a 30–60 m long initial section.

The measurement data of temperature differences in the scale of the initial and final sections of the car, as well as the lengths of these sections are given in the table.

As can be seen from table 4, using the jffle of the proposed method compared with K3BecTtQOf virtually eliminates the uneven cooling of the end sections of the roll, which increases the uniformity of the mechanical characteristics along the length of the roll.

The increase in mechanical properties along the length of rolled products reduces the amount of scrap during its production at a metallurgical plant and during processing at metal-smelting plants. In addition, the elimination of supercooled initial sections of the roll makes it possible to reliably capture the latter with a winder drum.

Claims (1)

Invention Formula Method for the production of low-grade rolled products including successively hot rolling, thermal treatment ten 2585464 rolling-up heating in a sectioned coolant device with a cooling intensity and rolling out the roll into a skein, which is due to the fact that, in order to increase the uniformity of the mechanical properties of the metal over the length of the initial and final parts of the roll, the flow rate of the chiller in at least one cooling section the devices are changed from zero to a predetermined value in accordance with the dependence QI  % -4t - (t, ) ; c - / j- V - ( At the entrance of the initial section of the roll and the cooling device and from the given value to zero in accordance with the dependence Q, I At the exit of the final section of the roll, where Q and the current costs of the cooler;  QO - coolant flow rate setpoint; t is the current time; 11, and t | - the time of the beginning of the regulation process at the entrance of the initial section of the roll and at the exit of the final section, respectively; C - adjustment time .t k1 V de K is a coefficient depending on type of cooling device, its size, grade of cooled steel and rolled cross-section; length of the cooling unit; roll speed t - V Known 150-200 1 "0-120 80-120 (iedooh- (overcooling) lazheyiye) Proposed 20-30 20-30 Do O, 13 (within the accuracy of the temperature sensor) G-4 1-4 30-60 1-4 Up to 0.13 Compiled by O. Rum Nceva Editor O. Bugir Tehred I. Veres Proofreader M “Maksikninets 5062/11 Circulation 518 Podpysikoe VShPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab, 4/5 Production and printing company, Uzhgorod, st. Project, 4