SU734298A1 - Arrangement for resistance thermal treatment of rods - Google Patents

Description

(54) UNIT FOR ELECTROCONTACT HEAT TREATMENT OF BARS

one

The invention relates to metallurgy, in particular to electrical equipment, and can be used in heat treatment (tempering, normalizing, hardening, improving, correcting carbide mesh, etc.) hot rolled and calibrated. bath rods, as well as during heating for the recrystallization of calibrated rods in the thermal-calibration production.

The unit can be used in the engineering industry for the heat treatment of long metal products.

A known automatic installation for electrical contact heating and cooling of pipes, comprising a heating device, a quenching tank with a sliding platform and a cooling device installed under it, made in the form of a perforated pipe and a hydraulic nozzle for supplying a cooling medium to the outer and inner surface of the products 1.

The disadvantage of this setup is the narrow field of application (mainly for quenching); impossibility

control of the cooling mode in the middle limits; the inability to provide a combined cooling mode (air and water) without reducing the performance.

The closest in the technical essence of the invention is a unit for electrocontact thermal bar processing, which contains series-connected transport devices with a device for loading, heating, hardening, cooling, heating for tempering and withdrawing 15 2.

On the unit during its normal operation, it is possible to perform tempering, normalization, quenching, improvement, recrystallization of a bar-shaped

20 lengths. In this case, the rods are successively passed through all devices of the installation.

The disadvantages of the known installation are low productivity.

25 installation, due to incomplete use of heating power during the execution, thermal modes,. associated only with heating, tempering, normalization, recrystallization, when one of the heating

devices disabled; including slow cooling, delaying the operation of the initial heating of each subsequent bar (for example, cooling in still air or intermittent forced cooling. Lrie correction of the carbide mesh in the structure of a whole series of steels;

- increased scatter of mechanical properties of heat-treated rods along their length due to uneven cooling in the bath due to uneven distribution of the steam jacket along the length of the rod, uneven flow of the cooling medium in the bath; reducing the cooling rate of the sections of the rods in contact with the supports and grips of the cooling device.

The aim of the invention is to increase productivity and expand the technological capabilities of the unit for the electrocontact heat treatment of rods, to improve the quality of the heat-treated rods.

The goal is achieved by supplying the unit with a refrigerator installed between the heating devices for quenching and cooling, and additional transporting devices connecting the refrigerator, cooling and heating devices for tempering.

In this case, the cooling device is made in the form of a sprayer, and the heating device for tempering is equipped with devices for loading and unloading.

Nd FIG. 1 shows the proposed unit, a top view; FIG. 2 is a section A-A in FIG. 1; in fig. 3 shows a section BB in FIG. one; in fig. 4 shows a section B-B in FIG. 2; in fig. 5 is a section of YYD in FIG. 2

The unit consists of two loading tables 1, parallel to the loading tables are mechanisms 2 of the cross feed of bars, behind the mechanisms and parallel to them are heating devices (quenching and heating) 3, 4, which are equipped with contacts 5 mounted on carts 6, under heating devices ; roller table 7 installed, and under it 8 lifting and lowering mechanisms 8, a shut-off device 9 is located along the roll table and a cut-off device 9 is located behind the first contact unit and a refrigerator 10 is parallel to it, an additional shipping device is installed parallel to the refrigerator for longitudinal conveyor and a heating device is installed unloading devices - containers 12 of finished products, the longitudinal conveyor rolling table

rods and rolls of the second heating unit, there is a sprayer device consisting of a frame with a drive 13, a wheel roller table 14, annular sprayers, sections 15, a locking device 16. The unit works as follows.

When performing modes of hardening, improvement, correction of the carbide mesh, normalization, followed by tempering, etc. interconnected and sequentially operated from heating devices 3 and 4 together with sprayer sections 15 on or off.

5, the wheel conveyor 14 is in operation, and the container 12 of the heating device 3 and the loading table 1 of the heating device 4 remain empty.

0 The rods are fed by a crane to the loading table 1 of the heating device 3, one by one through the mechanism 2 are fed to the live rolls 7 of the heating device 3 and

5 are fixed in the contacts 5 on the carriages 6 by means of the mechanism 8 for raising and lowering. After heating in the contacts, the next bar is lowered by the mechanism 8 and through the cutter 9, it is transferred to the refrigerator 10, which is a conveyor with an electromechanical drive with a large depth of speed control and serves to set it up

t necessary (based on the duration of the cooling) of the stock of heated rods, which ensures the operation of the heating device 3 without reducing its performance.

From the conveyor of the refrigerator 10, the rods alternately roll onto a longitudinal roller table 11, made in the form of drive rollers with a large depth of speed control, which, in synchronization with the wheel roller table 14, provides the required speed of movement of the rod and sprayer sections 15 in accordance with the cooling mode. Wheel roller 14 simultaneously with the movement of the bar

. ensures its rotation around its axis, which further improves the conditions for uniform cooling

f of the bar, and also protects it from bending. The pairs of wheels of the roller table 14 are located between the annular sprayer sections 15.

Bar cooling mode in a multi-position sprayer

0 Can be established with a sufficiently high degree of accuracy as follows:

a) switching on and off a series of sections 15 (depending on the required number and duration of intermittent cooling intervals or continuous cooling mode);

b) switching on and off the locking devices 16, which, with intermittent cooling, prevent the outflow of a cooler (for example, water) from the sprayer sections to the outside while the rod is moving;

c) the speed of movement of the rod through the sprayer device;

d) the flow rate, pressure of the cooling medium entering through the spray sections;

e) the ratio of the components of the cooling medium (for example, the vapor-air mixture).

From the sprayer the bar enters the heating device 4, which, like the heating device, the device 3 works without delays, since the cooling time of the rod in the sprayer is usually less than the heating time.

After heating, the bar through the cutter 9 enters the mechanism -2 of the transverse supply of the bars and then into the container of the heating device 4.

When executing the regimes of leave, normalization, recrystallization, etc. heating devices 3 and 4 operate independently of each other. Sprayer disconnected.

The rods are loaded by a crane onto the loading tables 1 of both heaters and, after heating, enter both containers 12. Thus, both heating devices of the unit are fully loaded.

The use of the unit will increase the productivity of labor, expand the technological capabilities of the application of electrocontact

heating for heat treatment of metal products, to improve the quality of machined rods.

According to calculations, the performance of such a unit compared to the possible capacity of the prototype unit with the same installed power of heating devices can be increased by at least 2 times.

ten

Claims (1)

1. USSR author's certificate number 396377, cl. From 21 And 1/40, .1968. 2, USSR Author's Certificate No. 203183, cl. E 04 C 5/00, 1962. (prototype).