Novel air cooling nozzle device for improving mechanical property of on-line heat treatment steel rail

Abstract

The utility model provides a novel air cooling nozzle device for improving the mechanical property of an on-line heat treatment steel rail, which comprises a plurality of nozzles, each nozzle comprises a nozzle body, the nozzle body is provided with a through main air outlet and a plurality of annular air outlets, and the main air outlet is arranged in the center of the nozzle body. The plurality of annular air outlets are uniformly distributed in the outer circumferential direction of the main air outlet; threads are arranged on the outer wall of one end of the nozzle body; the multiple nozzles are arranged on a rail head tread and a rail head side face of a steel rail, and a main air outlet of each nozzle is installed right opposite to the center position of the rail head tread and the center position of the rail head side face. According to the air cooling nozzle structure, the blowing area can be increased to enlarge an effective cooling area on the surface of the steel rail, so that the cooling strength of the rail head part of the steel rail is ensured, and deviation of a target cooling area and an actual cooling area caused by jumping of the steel rail in the online heat treatment process is also avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of metal materials, in particular to a novel air cooling nozzle device for improving the mechanical properties of an online heat-treated rail. Background Art

[0002] The development trend of railways in the world today is towards high speed and heavy load, which will inevitably increase the contact stress between wheels and rails, leading to the increase of contact fatigue and internal damage on the rail surface. Therefore, higher and higher requirements are put forward for the comprehensive performance of rails (especially strength and toughness). Through heat treatment, the tensile strength, elongation and impact toughness of rails can be increased by about 30%, 50% and 133% respectively, and the service life of rails can be at least doubled. The overall air-cooled quenching of rails is currently one of the most effective and economical methods to improve the comprehensive performance of rails.

[0003] For pearlite rails, the pearlite lamellar spacing determines the hardness and mechanical properties of the quenched rails. As the pearlite lamellar spacing decreases, the hardness of the hardened layer increases, and the increase gradually increases. The tensile strength and impact properties also increase as the pearlite lamellar spacing decreases. Therefore, how to obtain pearlite with a smaller lamellar spacing becomes the key to the full-length heat treatment of the rail.

[0004] The air-cooling nozzle device currently used in the rail production process is simple in structure, generally a circular nozzle structure or a contraction nozzle structure, and has only one air outlet, which cannot achieve a large quenching cooling rate and cooling area, resulting in a wide spacing between pearlite lamellae in pearlite rails, and the performance of heat-treated rails needs to be improved. At present, the air jet speed in the rail air-cooling online heat treatment process is subsonic, and the industry has never explored the application of supersonic jet technology in rail air-cooling quenching and the design of rail air-cooling nozzle devices.

[0005] Rail air-cooling quenching is an extremely complex process in which flow field, temperature field, organization field and stress field are coupled with each other. The organization field of heat-treated rails is determined by the temperature field, and the spacing between pearlite lamellae is mainly determined by the cooling rate of the quenching process. The cooling rate and temperature field of rail air-cooling quenching are mainly related to the flow field of the cooling medium, and changing the nozzle structural parameters will affect the external flow field and temperature field of the rail. In addition, with the increase of cooling rate, the spacing between pearlite lamellae gradually decreases, and the organization performance improves. Therefore, the structural design of the new air-cooling nozzle is used to increase the air jet speed and the blowing area to increase the cooling rate and cooling area of ​​quenching, thereby improving the mechanical properties of heat-treated rails.

[0006] The patent document with announcement number CN211160276U discloses a new type of nozzle that improves the performance stability of online heat-treated rails to solve the problem that the target cooling area on the rail head surface is easily deviated from the actual cooling area due to deformation and vibration of the rails. It includes a nozzle body, and the nozzle nozzle is a strip with a length of 10-16mm and an aspect ratio of 1.8 to 2.6. When installed, the length direction of the nozzle nozzles on both sides of the rail head is parallel to the side of the rail head, and the length direction of the nozzle nozzle on the rail head tread is perpendicular to the length direction of the rail. Compared with the circular nozzle, the jet cross-section of the patent is enlarged in the length direction of the nozzle, and only a small amount of medium flow is required to increase. Even if the rails are deviated by vibration, the spray area can cover the surface of the rails, expanding the effective cooling area of ​​the rail surface, eliminating the deviation of the target cooling area from the actual cooling area caused by the unevenness of the rails themselves and the vibration during the travel process, and improving the stability and uniformity of the performance of the rails after heat treatment. However, compared with the circular nozzle, this patent adopts a strip nozzle structure design, and does not adopt a Laval nozzle structure design. It only expands the effective cooling area of ​​the rail surface, but cannot increase the cooling rate of quenching, and therefore cannot improve the mechanical properties of the rail.

[0007] The patent document with announcement number CN103131826A discloses a rail online air jet quenching heat treatment simulation experimental device, which is composed of the following structures: Laval type flat slot nozzle system, rail guide system, rack system, valve system, compressed air pipeline system, roller system, detection instrument system, rail heating furnace system, etc. Using the wind, water, heating furnace and roller conditions of the smelting and rolling pilot experiment innovation platform, a rail online air jet quenching heat treatment simulation experimental device is designed and manufactured, and a rail online air jet quenching heat treatment simulation experimental method is developed. The heavy rail full-length online quenching simulation experimental research is carried out. The experimental method is simple and reliable, which can greatly shorten the heavy rail full-length online quenching process research cycle and reduce the process research cost. It is a feasible method for laboratory simulation experimental research at present, and can provide process technology support for the heavy rail online quenching production line. However, this patent mainly describes an online air jet quenching heat treatment simulation experimental device for rails, and cannot be applied to the online heat treatment rail industrial production process. It only describes the use of a Laval type flat slot nozzle system, and does not provide a detailed description of the cooling nozzle structure.

[0008] The patent document with announcement number CN212610798U discloses a nozzle device for the heat treatment process of rails, including a nozzle body, one end of the nozzle body is an air inlet and the other end is an air outlet, the air outlet includes a main air outlet and an auxiliary air outlet, the main air outlet and the auxiliary air outlet are divided inside the nozzle body, wherein each divided air outlet and the dividing end point are conical so that the main and auxiliary air outlets form a certain taper with the internal air inlet. The purpose of this patent is to provide a nozzle device for the heat treatment process of rails to ensure the cooling strength of the triangular rails on the rails. This utility model patent forms a certain taper at the air outlet by dividing the inside of the nozzle body, and does not have a completely new design of the nozzle device structure for the heat treatment process of rails, and cannot achieve an increase in the cooling rate and cooling area of ​​quenching, and thus cannot improve the mechanical properties of the rails.

[0009] The patent document with announcement number CN107130098A discloses a rail heat treatment device and heat treatment method, the device includes a heat treatment mechanism, a water supply mechanism, an air supply mechanism, a main frame and a rail placement mechanism for placing rails; the heat treatment mechanism includes a pressure stabilizing bellows, the pressure stabilizing bellows are respectively connected to the upper bellows, the lower bellows, the left bellows and the right bellows through a small ventilation pipe, and the upper bellows, the lower bellows, the left bellows and the right bellows are all provided with a first nozzle; the first nozzle of the upper bellows is placed just above the rail, the first nozzle of the lower bellows is placed just below the rail, and the central axis of the first nozzle of the upper bellows and the first nozzle of the lower bellows coincide with the central axis of the rail; the first nozzle of the left bellows and the first nozzle of the right bellows are symmetrically arranged on both sides of the rail; the water supply mechanism and the air supply mechanism are respectively connected to the pressure stabilizing risk; the rail placement mechanism is placed in the main frame. The patent is simple and easy to operate, and can ensure the heat treatment effect of the rail. However, this patent mainly describes a rail heat treatment device and a heat treatment method, which adopts a rail heat treatment device and process that combines air cooling and water cooling, which is quite different from the utility model patent applied to the online heat treatment process of the rail with air jet cooling, and does not describe the specific structure of the cooling nozzle in detail. The structure of the nozzle device is unknown. This patent cannot increase the cooling speed and cooling area of ​​the quenching, and therefore cannot improve the mechanical properties of the rail.

[0010] The patent document with announcement number CN108342552A discloses an online heat treatment device and process for rails, including a wind system, a water mist system and a heat treatment machine, the heat treatment machine includes an upper process equalizing pressure box, a lower process equalizing pressure box and a side process equalizing pressure box, the upper process equalizing pressure box, the lower process equalizing pressure box and the side process equalizing pressure box are respectively arranged above, below and on both sides of the rail conveyor line, the lower end face of the upper process equalizing pressure box, the upper end face of the lower process equalizing pressure box and the inner end face of the side process equalizing pressure box are all provided with nozzles, and the upper process equalizing pressure box, the lower process equalizing pressure box and the side process equalizing pressure box are all connected to the wind system and the water mist system. It can effectively control the temperature drop rate of the heat treatment of the rails, significantly improve the product qualification rate, be economical and environmentally friendly, significantly reduce energy consumption, and meet energy-saving requirements; the production process is simple and applicable, saves costs, and can conveniently and stably improve the performance of the rails by accurately controlling quenching cooling. However, the rail heat treatment device and process using a combination of air jet cooling and water mist cooling adopted in this patent are quite different from the utility model patent's application in the online heat treatment process of rails using air jet cooling. In addition, it only describes the use of a circular nozzle structure without a detailed description of the cooling nozzle structure. This patent cannot increase the cooling rate and cooling area of ​​quenching, and therefore cannot improve the mechanical properties of the rails. Utility Model Content

[0011] According to the technical problems raised above, a new air cooling nozzle device is provided to improve the mechanical properties of online heat treated rails. The technical means adopted by the utility model are as follows:

[0012] A novel air cooling nozzle device for improving the mechanical properties of an online heat treated rail comprises a plurality of nozzles, wherein the nozzle comprises a nozzle body, the nozzle body is provided with a through main air outlet and a plurality of annular air outlets, the main air outlet is arranged at the center of the nozzle body, and the plurality of annular air outlets are evenly distributed in the outer circumferential direction of the main air outlet;

[0013] One end of the main air outlet is the main air outlet inlet, and the other end is the main air outlet outlet; one end of the annular air outlet is the annular air outlet inlet, and the other end is the annular air outlet outlet; the main air outlet inlet and the annular air outlet inlet are located on the same side, and the main air outlet inlet and the multiple annular air outlet inlets constitute the air inlet of the nozzle; the main air outlet outlet and the annular air outlet outlet are located on the same side, and the main air outlet outlet and the multiple annular air outlet outlets constitute the air outlet of the nozzle;

[0014] The outer wall of one end of the nozzle body is provided with a thread for connecting with the wind box of the rail online heat treatment unit, and the thread is located on the inlet side of the main air outlet;

[0015] The multiple nozzles are arranged on the tread of the rail head and the side surface of the rail head, and the main air outlet of each nozzle is installed facing the center position of the tread of the rail head and the side surface of the rail head.

[0016] Furthermore, the main air outlet adopts a Laval type nozzle structure.

[0017] Furthermore, the diameter of the main air outlet inlet is 8-10 mm, the diameter of the main air outlet throat is 5-7 mm, and the diameter of the main air outlet outlet is 7-9 mm.

[0018] Furthermore, the annular air outlet adopts a straight nozzle structure.

[0019] Furthermore, there are six annular air outlets, and the angle between two adjacent annular air outlets is 60°.

[0020] Furthermore, the diameter of the annular air outlet is 2-4 mm.

[0021] Furthermore, the distance between the annular air outlet and the main air outlet is 6-8 mm.

[0022] Furthermore, the central axes of the main air outlet and the annular air outlet are parallel.

[0023] Furthermore, the distance between the nozzle and the rail head is 10-30 mm.

[0024] Compared with the prior art, the utility model has the following advantages:

[0025] 1. The utility model provides a new air-cooling nozzle device for improving the mechanical properties of online heat-treated rails. The structural design of the new air-cooling nozzle increases the spraying area to expand the effective cooling area on the rail surface, which not only ensures the cooling intensity of the rail head part, but also avoids the deviation between the target cooling area and the actual cooling area caused by the rail jumping during the online heat treatment process.

[0026] 2. The utility model provides a new air-cooling nozzle device for improving the mechanical properties of online heat-treated rails. The structural design of the new air-cooling nozzle increases the air jet speed to increase the cooling speed of the quenched rails. As the cooling speed increases, the pearlite lamellar spacing gradually decreases, thereby improving the mechanical properties of the heat-treated rails.

[0027] Based on the above reasons, the utility model can be widely promoted in the fields of rail air cooling quenching and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0029] Figure 1 It is the front view of the air-cooling nozzle device of the utility model.

[0030] Figure 2 It is a left view of the air-cooling nozzle device of the utility model.

[0031] Figure 3 This is a schematic diagram of the installation of the air-cooling nozzle device of the utility model.

[0032] In the figure: 01, main air outlet; 02, ring-shaped air outlet; 1, main air outlet inlet; 2, main air outlet outlet; 3, ring-shaped air outlet outlet; 4, ring-shaped air outlet inlet; 5, thread; 6, rail head. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0034] In order to solve the practical problem that the pearlite lamellar spacing of pearlite rails is wide and the performance of heat-treated rails still has room for improvement, the utility model increases the air jet speed and the blowing area through the structural design of the new air-cooling nozzle device to increase the cooling speed and cooling area of ​​quenching, thereby improving the mechanical properties of heat-treated rails. The utility model provides important reference value for exploring the application of supersonic jet technology in rail air-cooling quenching and the design of rail air-cooling nozzle devices, which is of great significance to improving the quality and comprehensive performance of heat-treated rails, and will also generate considerable economic benefits for rail manufacturing companies.

[0035] The utility model provides a novel air-cooling nozzle device for improving the mechanical properties of online heat-treated rails, including a plurality of nozzles, and the nozzle includes a nozzle body. One end of the nozzle is an air inlet and the other end is an air outlet, including a through main air outlet 01 and a plurality of annular air outlets 02 provided on the nozzle body, the central axis of the main air outlet 01 and the annular air outlet 02 are parallel; the main air outlet 01 is a Laval-type nozzle, one main air outlet 01 is arranged at the center of the nozzle, mainly to improve the quenching air jet cooling speed; the annular air outlet 02 is a straight-cylinder nozzle, a total of 6 are set, and are arranged around the main air outlet 01 at equal angles and distances, mainly to increase the quenching spray area. One end of the main air outlet 01 is the main air outlet inlet 1, and the other end is the main air outlet outlet 2; one end of the annular air outlet 02 is the annular air outlet inlet 4, and the other end is the annular air outlet outlet 3; the main air outlet inlet 1 and the annular air outlet inlet 4 are located on the same side, and the main air outlet inlet 1 and the multiple annular air outlet inlets 4 constitute the air inlet of the nozzle. The main air outlet outlet 2 and the annular air outlet outlet 3 are located on the same side, and the main air outlet outlet 2 and the multiple annular air outlet outlets 3 constitute the air outlet of the nozzle.

[0036] The diameter of the nozzle main air outlet inlet 1 is 8-10mm; the diameter of the nozzle main air outlet 01 is 5-7mm; the diameter of the nozzle main air outlet outlet 2 is 7-9mm; the diameter of the annular air outlet 02 is 2-4mm; the distance between the annular air outlet 02 and the main air outlet 01 is 6-8mm; the angle between two adjacent annular air outlets 02 is 60°. The thread 5 is processed on the outside of the nozzle body on one side of the air inlet, which is convenient for installation on the wind box of the rail online heat treatment unit (existing equipment). The nozzle is arranged on the tread of the rail head and the two sides of the rail head (existing equipment), and the main air outlet 01 of the nozzle is installed at the center of the tread of the rail head and the side of the rail head.

[0037] Example 1

[0038] like Figure 1 , Figure 2As shown, the utility model divides the nozzle air outlet into a main air outlet 01 and an annular air outlet 02. The main air outlet 01 is set at the center of the nozzle body, and there are 6 annular air outlets 02, which are evenly distributed in the outer circumferential direction of the main air outlet 01. The diameter of the main air outlet inlet 1 is 8-10mm; the diameter of the throat of the main air outlet 01 is 5-7mm; the diameter of the main air outlet outlet 2 is 7-9mm; the diameter of the annular air outlet 02 is 2-4mm; the distance between the annular air outlet 02 and the main air outlet 01 is 6-8mm; the angle between adjacent annular air outlets 02 is 60°. The specific size of the nozzle is designed according to the cross-section specifications of the rail. In this embodiment, for a 60kg / m rail, the nozzle is designed to have a main air outlet inlet 1 with a diameter of 8mm; a main air outlet 01 throat with a diameter of 5mm; a main air outlet outlet 2 with a diameter of 7mm; an annular air outlet 02 with a diameter of 2mm; a distance between the annular air outlet 02 and the main air outlet 01 of 6mm; and an angle of 60° between two adjacent annular air outlets 02.

[0039] The nozzle body is provided with a thread 5 on the outside of the air inlet side, and is installed on the wind box of the rail online heat treatment unit (existing equipment). The distance between the nozzle and the rail head 6 is adjusted by the wind box of the rail online heat treatment unit. The adjustment distance is generally 10-30mm. The nozzle is arranged on the tread and side of the rail head, and the main air outlet 01 of the nozzle is installed facing the center of the tread and side of the rail head. Figure 3 shown.

[0040] Compared with the traditional contraction type nozzle, the air cooling nozzle of the utility model increases the effective cooling area of ​​the rail surface by increasing the spraying area through the annular air outlet 02, thereby ensuring the cooling intensity of the rail head part (rail head 6), and avoiding the deviation between the target cooling area and the actual cooling area caused by the rail jumping during the online heat treatment process; the cooling speed of the quenched rail is increased by the injection intensity of the main air outlet 01, thereby improving the mechanical properties of the heat treated rail.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the utility model.

Claims

1. A new type of air cooling nozzle device for improving the mechanical properties of online heat treated rails, characterized in that: The nozzle comprises a plurality of nozzles, wherein the nozzle comprises a nozzle body, wherein the nozzle body is provided with a through main air outlet (01) and a plurality of annular air outlets (02), wherein the main air outlet (01) is arranged at the center of the nozzle body, and the plurality of annular air outlets (02) are evenly distributed in the outer circumferential direction of the main air outlet (01); One end of the main air outlet (01) is the main air outlet inlet (1), and the other end is the main air outlet outlet (2); one end of the annular air outlet (02) is the annular air outlet inlet (4), and the other end is the annular air outlet outlet (3); the main air outlet inlet (1) and the annular air outlet inlet (4) are located on the same side, and the main air outlet inlet (1) and the plurality of annular air outlet inlets (4) constitute the air inlet of the nozzle; the main air outlet outlet (2) and the annular air outlet outlet (3) are located on the same side, and the main air outlet outlet (2) and the plurality of annular air outlet outlets (3) constitute the air outlet of the nozzle; The outer wall of one end of the nozzle body is provided with a thread (5) for connecting to the wind box of the rail online heat treatment unit, and the thread (5) is located on one side of the main air outlet inlet (1); The plurality of nozzles are arranged on the tread surface and the side surface of the rail head, and the main air outlet (01) of each nozzle is installed facing the center position of the tread surface and the side surface of the rail head.

2. The novel air cooling nozzle device for improving the mechanical properties of online heat treated rails according to claim 1 is characterized in that: The main air outlet (01) adopts a Laval type nozzle structure.

3. The novel air cooling nozzle device for improving the mechanical properties of online heat treated rails according to claim 1 or 2, characterized in that: The diameter of the main air outlet inlet (1) is 8-10 mm, the diameter of the throat of the main air outlet (01) is 5-7 mm, and the diameter of the main air outlet outlet (2) is 7-9 mm.

4. The novel air cooling nozzle device for improving the mechanical properties of online heat treated rails according to claim 1 is characterized in that: The annular air outlet (02) adopts a straight-cylinder nozzle structure.

5. The novel air cooling nozzle device for improving the mechanical properties of online heat treated rails according to claim 1 or 4, characterized in that: There are six annular air outlets (02), and the angle between two adjacent annular air outlets (02) is 60°.

6. The novel air cooling nozzle device for improving the mechanical properties of online heat treated rails according to claim 1 or 4, characterized in that: The diameter of the annular air outlet (02) is 2-4 mm.

7. The novel air cooling nozzle device for improving the mechanical properties of online heat treated rails according to claim 1 is characterized in that: The distance between the annular air outlet (02) and the main air outlet (01) is 6-8 mm.

8. The novel air cooling nozzle device for improving the mechanical properties of online heat treated rails according to claim 1 is characterized in that: The central axes of the main air outlet (01) and the annular air outlet (02) are parallel.

9. The novel air cooling nozzle device for improving the mechanical properties of online heat treated rails according to claim 1, characterized in that: The distance between the nozzle and the rail head (6) is 10-30 mm.

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