EA027490B1 - Device for thermally processing rails - Google Patents

Abstract

The invention relates to the field of metallurgy and, in particular, to the thermal processing of rails, including railroad rails. The proposed invention for thermally processing rails allows for simultaneously solving the problem of coupling a pipeline and a collector when the coupled surfaces thereof differ in form and achieving a gradual change in speed of a flow of coolant medium at the entrance to the collector, and also allows for dividing the flow of coolant medium inside the collector. Together, these features allow for equally distributing a flow of coolant medium in a collector and for achieving the required (specified) equal distribution of coolant medium on the surface of a rail.

Description

The invention relates to the field of metallurgy, in particular to heat treatment of rails, including railway rails.

State of the art

A known cooling system for a hot-rolled long steel beam, in particular a rail (KI 2450877, \ UO 2009/107639, IPC V21B 45/02), containing many chambers located in the longitudinal direction of the rolled steel beam, each of the many chambers made with a blow hole facing from the chamber to the rolled steel beam for blowing compressed air for cooling introduced into the chamber through a gas inlet connected to the chamber, a nozzle plate with a plurality of nozzle openings located on the blow hole and so that it faces a rolled steel beam, a nozzle for supplying cooling water to the chamber and a straightening plate located between the gas inlet and the nozzle for supplying cooling water and preventing the nozzle plate from directly impacting with compressed gas for cooling introduced through the inlet for gas, while the cooling system is configured to spray the cooling medium obtained by mixing the cooling water supplied through a nozzle for supplying cooling water and compressed ha and for cooling that is introduced through the gas inlet and rectified in the rectifying plate toward the rolled steel bar through the nozzle holes of the nozzle plate for uniform cooling of the surfaces of the rolled steel bar.

This method is characterized in that the heat treatment of the rail is carried out by a medium with constant cooling ability, which does not provide a flexible change in the cooling rate during the heat treatment of one rail to obtain optimal rail characteristics.

The disadvantage of the system is that the nozzles supplying water are located after the straightening plate and supply water directly to the nozzle plates, which does not allow to obtain a fairly uniform distribution of water in the air.

Therefore, an uneven distribution of the cooling medium (air-water mixture) is formed over the nozzle plate. As a result, this leads to uneven spraying of the cooling medium through the nozzle openings and, accordingly, to uneven cooling of the heat-treating surface of the rail (steel beam).

Another disadvantage is the means of achieving uniform distribution of air in the chamber, namely, a straightening plate mounted horizontally in a wide part of the chamber with the formation of such a gap in which compressed gas for cooling, passing between the side edges of the straightening plate and the inner walls of the wide part of the chamber, evenly distributed in the narrow part of the camera. To ensure uniform distribution of air to the installation of a straightening plate, from the point of view of the authors of the claimed invention, high requirements must be imposed, since with slight deviations during installation in the chamber there is a significant redistribution of air in the chamber.

In addition, the achievement of the technical result indicated in this patent is facilitated by the shape of the chamber, which is formed by a wide part, made wide for gas inlet, a narrow part, the width of which is smaller than that of the wide part, and an inclined part that connects the wide and narrow parts, while the blow hole is located at the end of the narrow part.

Such a complex shape of the chambers is a disadvantage in terms of ease of design, layout and installation of devices for heat treatment of rails. Practical experience shows that the shape of the collectors is determined based on the specific conditions of the design of the heat treatment plant and it is advisable to use various forms of the upper, lower, side collectors, for example, for heat treatment of rails of variable and / or asymmetric profile, or long steel profiles, or design of installations in cramped production facilities conditions.

The invention is known A method and a device for heat treatment of a rail (patent KI 2456352, С2Ш 9/04), comprising mechanisms for loading, unloading, positioning and fixing the rail, a turbocharger, a duct system and manifolds with nozzle openings for supplying a cooling medium to the rail head and sole simultaneously , positioning mechanisms for ducts and manifolds with nozzle openings, a cooling medium control system, a temperature control system, characterized in that it has a pulsed quasine system continuous and / or continuous injection of water into an air stream containing a water tank, a system of water pipelines, water flow and pressure regulators in the form of controlled valves and controlled control valves, pulse injectors with a control system for water injection in a pulsed quasi-continuous and / or continuous mode into the air stream with a controlled change in the degree of air humidity and its pressure to ensure changes in the cooling ability of the medium, while the mechanisms of loading, unloading, positioning Hovhan and fixing rails adapted to be positioned during processing of the rail head-down position. The described method allows you to set the cooling mode and control the cooling rate of the rail, but at the inlet of the cooling medium into the collector there appears an uneven flow of the cooling medium due to a sharp change in the flow velocity due to the difference in cross sections (the cross section of the gas pipeline is much smaller than the cross section of the collector), which leads to an insufficiently uniform distribution of the cooling medium inside the collector.

Disclosure of invention

The technical result is the simultaneous coupling of mating surfaces of the pipeline and the manifold that differ in shape and a smooth change in the flow rate of the cooling medium at the inlet to the collector, as well as the dissection of the flow of cooling medium inside the collector, which together contributes to a uniform distribution of the flow of cooling medium in the collector and obtain the desired ) uniform distribution of the cooling medium on the rail surface.

The technical result is achieved in a device for heat treatment of a rail containing a system of gas pipelines, water pipelines, a system of pulsed quasi-continuous and / or continuous injection of water into a gas stream, including pulse injectors with a control system for injecting water in a pulsed quasi-continuous and / or continuous mode into a stream gas environment with a controlled change in the degree of humidity of the gas and its pressure to ensure changes in the cooling ability of the medium, cooling modules, each of which contains upper and / or lateral and / or lower manifolds for supplying a cooling medium simultaneously to the rail head and sole, in which according to the invention, the gas supply pipelines are coupled to the manifolds via adapter flanges with integrated injectors, the outlet openings of which are directed into the gas pipelines environment for the formation of a cooling medium, while at least in the upper collectors installed dividers.

Brief Description of the Drawings

FIG. 1 is a schematic view of an arrangement of cooling modules, where:

- rail;

- cooling module;

- top collector;

- lateral collector;

- lower collector.

FIG. 2- schematic view of a cooling module, where:

I - rail;

- top collector;

- lateral collector;

- lower collector;

- gas pipelines;

- water pipelines;

- control system;

- lattice with guide holes;

- adapter flange;

- injector.

FIG. 3 is a schematic view of a manifold with a transition flange (option I), where:

- collector;

- gas supply pipeline;

- water pipelines;

- adapter flange;

II - a hole for entering the cooling medium;

- injector;

- divider

FIG. 4 is a schematic view of a rail with collector grids, where:

- rail;

- lattice;

9a - guide holes.

FIG. 5 is a schematic view of a divider in a collector, where:

- collector;

- lattice;

9a - guide holes;

- divider;

- cooling fluid inlet;

- the width of the ramp of the divider;

φ is the angle between the slopes of the divider;

B is the width of the lattice;

£ is the distance from the divider to the grate; p is the width of the inlet 11 of the collector.

FIG. 6 is a schematic view of a manifold with a transition flange (option II).

- 2 027490

FIG. 7 is a schematic view of a manifold with a transition flange (option III).

FIG. 8 is a schematic view of a manifold with a transition flange (option IV).

FIG. 9 is a schematic view of a manifold with a transition flange (option V).

FIG. 10 is a schematic view of a manifold with a transition flange (option VI).

FIG. 11 is a schematic view of a manifold with a transition flange (option VII).

FIG. 12a, b, c, d - graphs of the distribution of hardness along the length of the rail.

Preferred Embodiment

Along the length of the rail 1 (Fig. 1), cooling modules 2 are arranged in series. The number of cooling modules 2 is determined in such a way as to ensure cooling of the entire length of rail 1. At the same time, each cooling module 2 may contain: an upper 3 collector, and / or one side 4 collector , and / or two lateral 4 collectors and / or lower 5 collector (Fig. 1) located along the respective cooled surfaces of rail 1. Collectors 3, 4, 5 are connected to the piping system 6 of the gas medium connected to the piping system 7 of water. System 8 (Fig. 2) pulsed quasi-continuous and / or continuous injection of water into the gas stream.

It is preferable to make the collectors 3, 4, 5 in the form of a longitudinally oriented parallelepiped (Fig. 3) or other (different) types of shapes depending on the types of heat-treating surfaces and the layout conditions of the cooling modules 2. Some possible options are shown in Fig. 6, 7, 8, 9, 10, 11. The collector 3, 4, 5 has an inlet 11 providing an input of cooling medium, and the side facing the surface of the rail 1 is a grating 9 (Fig. 2) with guide holes 9a (Fig. 4, 5) for supplying a cooling medium to the heat-treatable surface of the rail. The area of the inlet 11 of the collector may be less than or equal to the area of the grille 9 of the collector. In addition, the inlet 11 of the collector 3, 4, 5 can be located both parallel and at an angle to the grill 9 with the guide holes 9a. The gas pipeline 6 is interfaced with the manifold 3, 4, 5 by the adapter flange 10 (Fig. 2, 3), which in the best way ensures the connection of the gas pipeline 6 and the manifold 3, 4, 5, which significantly differ in the shape of the mating surfaces, and at the same time provides a smooth change flow rates of the cooling medium at the inlet to the collector.

An injector 12 is integrated in the adapter flange 10, so that its outlet is directed into the gas medium conduit 6 (FIG. 3) to form a cooling medium. In the collector 3, 4, 5, a divider 13 is installed (Fig. 3, 5), which ensures the dissection of the flow of cooling medium inside the collector. The divider 13 is a gable surface (Fig. 5). The length of the divider 13, as a rule, has from 0.5 to 0.9 the length of the collector, the width of 1 slope of the divider is calculated by the formula ρ / (28ίη (φ / 2)) <1 <ϋ / (2δίη (φ / 2)), where ρ is the width of the inlet 11;

φ is the angle between the surfaces of the slope of the divider, with φ <180;

B is the width of the collector.

With a ramp ramp width of 1 = b / (28sh (<p / 2)), the divider will cut off the collector cross-section in full width and the entire coolant flow will be redirected from the manifold inlet 11 only to the end sections of the collector, which will lead to a nonuniform coolant flow to rail surface. For 1 <ρ / (2δίη (φ / 2)), part of the flow of the cooling medium will go directly to the openings of the lattice, which will also lead to inhomogeneity of the flow. This will lead to a higher rate of flow of the cooling medium from the guide holes 9a, as a consequence, to a higher cooling rate of the rail surface in these places, resulting in a heterogeneity of the rail properties along the length.

Installation in the collector of the divider 13 symmetrically with respect to the inlet 11 leads to the separation of the flow into equal parts.

It is possible to use a divider 13 having a surface with round holes and / or grooves of a rectangular and / or other shape. In addition, the surface of the divider 13 in length may have a variable width.

The presence of transitional flanges, gable dividers and gratings with guide holes allow the use of manifolds of various shapes for differentiated heat treatment (in accordance with the types of heat-treated products).

The preferred option for installing the dividers 13 in the collectors 3, 4, 5. Possible device options when the divider 13 can only be installed in the collectors 3 or 4, or 5, or 3 and 4, or 3 and 5, or 4 and 5, which will allow use the proposed device, for example, for rails of variable and / or asymmetric profile or long symmetrical and / or asymmetric steel profiles.

The device operates as follows.

The device allows for adjustable differential cooling in both through-flow and cage modes. In the continuous cooling mode, the rail moves relatively

- 3 027490 cooling modules with programmable speed. In the charge cooling mode, the rail is stationary relative to the cooling modules. Rail 1 with rolling or separate heating is fed into the quenching device, positioned relative to the cooling modules 2. Cooling starts from a temperature not lower than the austenization temperature of the rail.

A turbocharger (not shown in the figure) supplies gas through pipelines 6. The water flowing through pipelines 7, injectors 12, built into the adapter flange 10, are injected into the pipelines 6 of the gas medium, where the mixing of water with gas leads to the formation of a cooling medium. The control system 8, depending on the temperature and humidity of the environment, regulates the flow of the mass gas flow rate, providing a given pressure in the collectors 3, 4, 5, and injected water, adjusting their mass ratio in a given interval to obtain a cooling medium with specified characteristics, which ensures a given (constant / required) flow rate of the coolant flow.

The resulting cooling medium from the pipeline 6 through the adapter flange 10, which helps to reduce the resistance to the flow of the cooling medium, and the inlet 11 enters the collectors 3, 4, 5, where the divider 13 inside the collectors 3,4,5 cuts the flow of the cooling medium and ensures uniform distribution by volume of collectors.

Next, the cooling medium through the guide holes 9a of the lattice 9 of the collectors 3,4,5 is directed to the corresponding cooled surface of the rail 1.

Implementation example.

Full-profile samples of P65-type rails with a length of 1.6 m were subjected to heat treatment, two cooling modules were installed in series along the rail, containing upper, two lateral and lower collectors in order to be able to evaluate the uniformity of flow on the rail surface both along the length of one (any) collector and at the junctions (junctions) of the cooling modules. Samples of rails were selected from one smelting of K76F steel with a chemical composition: 0.78% carbon, 0.93% manganese, 0.36% silicon, 0.077% vanadium, 0.038% chromium, 0.009% phosphorus, 0.004% sulfur. Rail samples were heated in an experimental furnace-type furnace. The temperature of the heating rails for hardening was 850 ° C. The samples were cooled according to the program-defined mode for a given chemical composition of rail smelting according to patent No. 2456352, IPC S2GO 9/04, S2GO 11/00 using the proposed device. The same type of rail samples was tested in a continuous mode in accordance with patent applications KI 2011131883, KI 2011144110.

The macro- and microstructure of heat-treated samples was evaluated on full-profile templates. No dark and light bands were observed in the macrostructure; the microstructure is perlite of varying degrees of dispersion.

The uniformity of the heat treatment of the rails along the length of the collectors was assessed by the hardness of the HB measured on the roll surface of the rail head (PCG) with a pitch of 50 mm, after removing the surface decarburized layer to 0.5 mm. The distribution (values) of Brinell hardness on the tread surface of the rail head are shown in FIG. 12.

a) for the proposed device in the charge mode without adapter flange, but with a divider;

b) for the proposed device in the cage mode with a transitional flange, but without a divider;

c) for the proposed device in the cage mode with an adapter flange and divider.

g) for the proposed device in a continuous mode with an adapter flange and divider.

From the graph in FIG. 12a shows that the spread of hardness is within 25 HB, from the graph in FIG. 12b scatter within 50 HB. The graphs in FIG. 12c, d show that the spread of hardness is less than 10 HB and confirms the best result in the uniformity of cooling of the rail.

Industrial applicability

The proposed device for heat treatment of rails simultaneously solves the problem of pairing mating surfaces of the pipeline and the manifold and smoothly changing the flow rate of the cooling medium at the inlet to the collector, as well as cutting the flow of the cooling medium inside the collector, which together contributes to a uniform distribution of the flow of cooling medium in the collector and obtaining the required (predetermined) uniform distribution of the cooling medium on the rail surface.

Claims (13)

CLAIM 1. Device for heat treatment of a rail, comprising a system of gas pipelines, water pipelines, a system of pulsed quasi-continuous and / or continuous injection of water into a gas stream, including pulse injectors with a control system for injecting water in a pulsed quasi-continuous and / or continuous mode into a gas stream with an adjustable change in the degree of humidity of the gas and its pressure to ensure changes in the cooling ability of the medium, cooling modules, each of which contains a top and / or side, and / or lower manifolds for supplying a cooling medium to the rail head and sole simultaneously, characterized in that the gas supply pipelines are interfaced with the manifolds by means of adapter flanges with - 4 027490 with built-in injectors, the outlet openings of which are directed into the pipelines of the gaseous medium to form a cooling medium, while at least in the upper collectors are installed dividers. 2. The device according to claim 1, characterized in that the collectors are combined in cooling modules, each of which contains at least one upper, two side, one lower collectors. 3. The device according to claim 1, characterized in that the collector preferably has the shape of a longitudinally oriented parallelepiped. 4. The device according to claim 1, characterized in that the inlet of the collector can be located at an angle to the lattice with guide holes. 5. The device according to claim 1, characterized in that the inlet of the collector is equal in area to or less than the area of the collector lattice. 6. The device according to claim 1, characterized in that the transitional flange has the shape of a truncated pyramid that mates the pipeline with the collector. 7. The device according to claim 1, characterized in that the divider has a gable surface. 8. The device according to claim 1, characterized in that the angle between the slopes of the divider is set depending on the width of the inlet, the width of the grate and the distance from the divider to the grate with guide holes. 9. The device according to claim 1, characterized in that the divider has a length of 0.5-0.9 length of the collector and is installed symmetrically with respect to the inlet of the collector. 10. The device according to claim 1, characterized in that the surface of the divider can have round holes and / or grooves of a rectangular or other shape. 11. The device according to claim 1, characterized in that the surface of the divider along the length may have a variable width. 12. The device according to claims 1 and 3, characterized in that the collector can be made in the form of a tank having a circle in cross section. 13. The device according to claims 1, 3, 12, characterized in that the collector can be made in the form of a tank having a polygon in cross section.