A special heat treatment furnace for low temperature tempering of wear-resistant steel plate and heat treatment method thereof

Abstract

The present invention proposes a special heat treatment furnace for low-temperature tempering of wear-resistant steel plates and a heat treatment method thereof, comprising a loading roller, a centering device, an inlet sealing chamber, a heat treatment furnace body, an outlet sealing chamber, a furnace rear quick cooling system and a discharge roller arranged in sequence along the production line. The heat treatment furnace body is divided into a heating section and a heat preservation section. A temperature-adjusting burner heating system is installed in the heating section and the heat preservation section. A hot air heating system and a circulation system are also provided in the heat preservation section. Flue gas from other heat treatment furnaces is introduced for supplementary heat and temperature adjustment and then sent into the heat preservation section to equalize the heat of the steel plate. The present invention adopts a dual heating system to achieve rapid and uniform heating of the steel plate, thereby improving the temperature uniformity and production efficiency of the low-temperature tempering heat treatment of the steel plate.

Description

Technical Field

[0001] The present application relates to the technical field of heat treatment of steel plates, and in particular to a special heat treatment furnace for low-temperature tempering of wear-resistant steel plates and a heat treatment method thereof. Background Art

[0002] The heat treatment of steel plates is to change the organizational structure of steel plates through normalizing, quenching, annealing, tempering and other processes, so as to obtain different mechanical properties and meet different use requirements. At present, in large steel plate heat treatment workshops, in order to achieve continuous high production, continuous heat treatment furnaces are usually used for batch heating. Among them, the normalizing and quenching heat treatment processes of steel plates use high-temperature continuous heat treatment furnaces with radiant tube heating and controllable furnace atmosphere; while the tempering heat treatment of steel plates is achieved in another continuous heat treatment furnace, which uses self-preheating gas burners / high-speed burners to heat the furnace with open flames, and uses segmented pulse combustion control technology to make the furnace temperature reach the target temperature required for heat treatment of steel plates. However, for some wear-resistant steel plates, when low-temperature tempering heating (steel plate temperature 150~250℃) is required, the furnace temperature is required to be controlled at 160~260℃ and the furnace temperature is required to be uniform. Since the existing low-temperature continuous heat treatment furnace is designed for medium and high temperature tempering, it is difficult to achieve the furnace temperature of 160~260℃ with good uniformity required by the low-temperature heat treatment process. For this reason, some workshops use the method of introducing high-speed airflow into the continuous heat treatment furnace to disturb the furnace to achieve furnace temperature uniformity, but the effect is not good, the structure is complex, and the energy consumption is high.

[0003] In addition, natural cooling is generally adopted for the steel plates coming out of the furnace on a cooling bed. Since the temperature of the low-temperature tempered steel plates themselves is relatively low and the natural convection effect is poor, it usually takes a long time to cool down. The cooling bed has a large area, which restricts the production rhythm.

[0004] Therefore, there is an urgent need for a dedicated low-temperature tempering heat treatment furnace and a heat treatment method thereof to solve the above problems and improve the temperature uniformity and production efficiency of low-temperature tempering heat treatment of steel plates. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a special heat treatment furnace for low temperature tempering of wear-resistant steel plates and a heat treatment method thereof in view of the above-mentioned problems.

[0006] The embodiment of the present application is implemented as follows: The embodiment of the present application provides a special heat treatment furnace for low-temperature tempering of wear-resistant steel plates, which is characterized in that it includes a loading roller, a centering device, an inlet sealing chamber, a heat treatment furnace body, an outlet sealing chamber, a post-furnace rapid cooling system and a unloading roller arranged in sequence along the production line. The heat treatment furnace body is divided into a heating section and a heat preservation section. A temperature-adjusting burner heating system is installed in the heating section and the heat preservation section. A hot air heating system and a circulation system are also provided in the heat preservation section. The flue gas from other heat treatment furnaces is introduced to supplement heat and adjust the temperature before being sent into the heat preservation section to equalize the heat of the steel plate.

[0007] In some optional embodiments, the hot air heating system includes a hot air nozzle, a hot air furnace and an induced draft fan. The hot air nozzle is installed in the insulation section and is connected to the air outlet of the hot air furnace installed outside the furnace through a hot air duct. The air inlet of the hot air furnace is connected to the air outlet of the induced draft fan through an air inlet duct, and the air inlet of the induced draft fan introduces flue gas from other heat treatment furnaces.

[0008] In some optional embodiments, the heat preservation section is connected to a hot air circulation fan through a hot air circulation duct, and the hot air circulation duct on the outlet side of the hot air circulation fan is connected to the air inlet duct.

[0009] In some optional embodiments, the outlet-side air inlet duct of the induced draft fan is connected to the chimney through an exhaust main pipe, and the outlet of the hot air circulation fan is connected to the exhaust main pipe through an exhaust branch pipe.

[0010] In some optional implementation schemes, the hot air duct, air inlet duct, hot air circulation duct, exhaust main pipe and exhaust branch pipe are respectively provided with solenoid valves.

[0011] In some optional embodiments, the circulation system includes multiple groups of clockwise rotating circulation fans and counterclockwise rotating circulation fans installed on the top of the insulation section furnace, and the clockwise rotating circulation fans and counterclockwise rotating circulation fans are arranged alternately.

[0012] In some optional embodiments, the post-furnace rapid cooling system includes spray boxes or nozzles symmetrically arranged corresponding to the upper and lower surfaces of the steel plate. The spray boxes or nozzles are connected to the rapid cooling fan through a rapid cooling pipe to spray high-speed airflow to cool the steel plate.

[0013] A method for using a special heat treatment furnace for low temperature tempering of wear-resistant steel plates, characterized in that it includes the following contents: The heat-treated steel plate passes through a certain speed into the heat treatment furnace, and runs continuously to the unloading area according to the predetermined time in the furnace. During this period, the heating is completed by the temperature-adjusting burner heating system installed in the furnace. The flue gas from other heat treatment furnaces is supplemented with heat to the target temperature through the hot air heating system and the circulation system, and then sent into the heat treatment furnace to complete the equalization of the steel plate. Finally, the steel plate runs to the quick cooling system after the furnace until it drops to the target temperature.

[0014] The beneficial effects of the present application are as follows: the present application provides a special heat treatment furnace for low-temperature tempering of wear-resistant steel plates and a heat treatment method thereof, which adopts a dual heating system to achieve rapid and uniform heating of the steel plates, and can simultaneously introduce flue gas from other heat treatment furnaces to directly heat the steel plates to save energy, and adopts a post-furnace fast cooling device to replace the traditional cooling bed to improve the production rhythm. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 A schematic diagram of a special heat treatment furnace for low temperature tempering of wear-resistant steel plates according to an embodiment of the present application; Figure 2 Schematic diagram of a hot air heating system according to an embodiment of the present application. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0018] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0019] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0020] In the description of the present application, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the application is usually placed when in use. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, terms such as "horizontal", "vertical", and "overhanging" do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0021] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0022] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0023] The features and performance of the present application are further described in detail below in conjunction with the embodiments.

[0024] like Figure 1 , Figure 2 As shown, the present invention proposes a special heat treatment furnace for low-temperature tempering of wear-resistant steel plates, comprising a loading roller 1, a centering device 2, an inlet sealing chamber 3, a heat treatment furnace body 4, an outlet sealing chamber 5, a post-furnace fast cooling system 6 and a discharge roller 7 arranged in sequence along the production line. The heat treatment furnace body is divided into a heating section 8 and a heat preservation section 9. A temperature-adjusting burner heating system 10 is installed in the heating section and the heat preservation section. A hot air heating system 11 and a circulation system are also provided in the heat preservation section. The flue gas from other heat treatment furnaces is introduced into the heat preservation section for supplementary heat and temperature adjustment, and then sent to the heat preservation section to equalize the heat of the steel plate.

[0025] The temperature-controlled burner heating system is installed in the heating section and the insulation section, and adopts a large air-fuel ratio mode, which is used for low-temperature tempering rapid heating and uniform heating in non-smoke heating mode.

[0026] The hot air heating system includes a hot air nozzle 10.1, a hot air furnace 10.2 and an induced draft fan 10.3. The hot air nozzle is installed in the heat preservation section and is connected to the air outlet of the hot air furnace installed outside the furnace through a hot air duct 10.4. The air inlet of the hot air furnace is connected to the air outlet of the induced draft fan through an air inlet duct 10.5. The air inlet of the induced draft fan introduces the flue gas of other heat treatment furnaces. The induced draft fan introduces the flue gas of other heat treatment furnaces into the heat preservation section to heat the steel plate, thereby saving energy consumption.

[0027] The heat preservation section is connected to the hot air circulation fan 10.7 through the hot air circulation duct 10.6, and the hot air circulation duct on the outlet side of the hot air circulation fan is connected to the air inlet duct. The flue gas in the heat preservation section enters the hot air furnace again through the circulation duct and the hot air circulation fan, and enters the heat preservation section again after being reheated and heated, and the cycle repeats until the flue gas heating is completed.

[0028] The air inlet duct at the outlet side of the induced draft fan is connected to the chimney 10.9 through the exhaust main pipe 10.8, and the outlet of the hot air circulation fan is connected to the exhaust main pipe through the exhaust branch pipe 10.10. At the same time, solenoid valves are respectively provided on the hot air duct, air inlet duct, hot air circulation duct, exhaust main pipe and exhaust branch pipe.

[0029] The on and off of each pipeline is controlled by the solenoid valve to realize the flue gas heating and non-flue gas heating modes, as follows: In the non-smoke mode, the insulation section uses a temperature-controlled burner heating system installed on the furnace body to complete the uniform heating of the steel plate. The flue gas heating system closes the solenoid valves on the hot air furnace and the hot air duct, and the furnace gas and flue gas are sent into the chimney through the exhaust branch pipe through the hot air circulation fan and discharged outside the workshop.

[0030] In the flue gas heating mode, the exhaust fan sends the flue gas from other heat treatment furnaces into the hot air furnace. After the hot air furnace supplements heat and adjusts the temperature, it is sent to the hot air nozzle to equalize the steel plate, and then the hot air circulation fan extracts it into the chimney and discharges it outside the workshop. In addition, by controlling the opening of the solenoid valve, the flue gas at the outlet of the hot air circulation fan can be partially returned to the hot air furnace for heating.

[0031] The circulation system includes a plurality of groups of clockwise rotating circulation fans 12 and counterclockwise rotating circulation fans 13 installed on the top of the insulation section furnace. The clockwise rotating circulation fans and the counterclockwise rotating circulation fans are arranged alternately to fully disturb the flue gas and evenly heat the steel plate.

[0032] The post-furnace rapid cooling system includes spray boxes or nozzles 14 symmetrically arranged corresponding to the upper and lower surfaces of the steel plate. The spray boxes or nozzles are connected to the rapid cooling fan through a rapid cooling pipeline to spray high-speed airflow to cool the steel plate, eliminate the cooling bed equipment, reduce the unit footprint, and improve the production rhythm.

[0033] The method for using the above heat treatment furnace for low temperature tempering of wear-resistant steel plates includes the following contents: The heat-treated steel plate enters the heat treatment furnace at a speed of 10-30m / min, and runs continuously to the unloading area according to the predetermined time in the furnace. During this period, the heating is completed by the temperature-adjusting burner heating system installed in the furnace; the flue gas from other heat treatment furnaces is supplemented with heat to the target temperature (for example, 150-250℃) through the hot air heating system and the circulation system, and then sent into the heat treatment furnace to complete the steel plate uniform heating; finally, the steel plate runs to the quick cooling system after the furnace until it drops to the target temperature.

Claims

1. A special heat treatment furnace for low temperature tempering of wear-resistant steel plates, characterized in that: It includes a loading roller, a centering device, an inlet sealing chamber, a heat treatment furnace body, an outlet sealing chamber, a rear-furnace quick cooling system and a discharge roller which are sequentially arranged along the production line. The heat treatment furnace body is divided into a heating section and a heat preservation section. A temperature-adjusting burner heating system is installed in the heating section and the heat preservation section. A hot air heating system and a circulation system are also provided in the heat preservation section. The flue gas from other heat treatment furnaces is introduced to supplement heat and adjust the temperature before being sent into the heat preservation section to soak the steel plate.

2. A special heat treatment furnace for low temperature tempering of wear-resistant steel plates according to claim 1, characterized in that: The hot air heating system comprises a hot air nozzle, a hot air furnace and an induced draft fan. The hot air nozzle is arranged in the insulation section and is connected with the air outlet of the hot air furnace arranged outside the furnace through a hot air duct. The air inlet of the hot air furnace is connected with the air outlet of the induced draft fan through an air inlet duct, and the air inlet of the induced draft fan introduces flue gas from other heat treatment furnaces.

3. A special heat treatment furnace for low temperature tempering of wear-resistant steel plates according to claim 2, characterized in that: The heat preservation section is connected to the hot air circulation fan through a hot air circulation pipeline, and the hot air circulation pipeline at the outlet side of the hot air circulation fan is connected to the air inlet pipeline.

4. A special heat treatment furnace for low temperature tempering of wear-resistant steel plates according to claim 3, characterized in that: The air inlet duct at the outlet side of the induced draft fan is connected to the chimney through an exhaust main pipe, and the outlet of the hot air circulation fan is connected to the exhaust main pipe through an exhaust branch pipe.

5. A special heat treatment furnace for low temperature tempering of wear-resistant steel plates according to claim 4, characterized in that: The hot air duct, the air inlet duct, the hot air circulation duct, the exhaust main pipe and the exhaust branch pipe are respectively provided with electromagnetic valves.

6. A special heat treatment furnace for low temperature tempering of wear-resistant steel plates according to claim 5, characterized in that: The circulation system comprises a plurality of groups of clockwise rotating circulation fans and counterclockwise rotating circulation fans installed on the top of the heat preservation section furnace, and the clockwise rotating circulation fans and counterclockwise rotating circulation fans are arranged alternately.

7. A special heat treatment furnace for low temperature tempering of wear-resistant steel plates according to claim 1 or 6, characterized in that: The post-furnace rapid cooling system comprises spray boxes or nozzles symmetrically arranged corresponding to the upper and lower surfaces of the steel plate. The spray boxes or nozzles are connected to the rapid cooling fan through a rapid cooling pipeline to spray high-speed airflow to cool the steel plate.

8. A method for using the special heat treatment furnace for low temperature tempering of wear-resistant steel plates according to claim 7, characterized in that: It includes the following: The heat-treated steel plate passes through a certain speed into the heat treatment furnace, and runs continuously to the unloading area according to the predetermined time in the furnace. During this period, the heating is completed by the temperature-adjusting burner heating system installed in the furnace. The flue gas from other heat treatment furnaces is supplemented with heat to the target temperature through the hot air heating system and the circulation system, and then sent into the heat treatment furnace to complete the equalization of the steel plate. Finally, the steel plate runs to the quick cooling system after the furnace until it drops to the target temperature.

Images