Multifunctional heat treatment furnace, use method thereof and production line comprising multifunctional heat treatment furnace

Abstract

The invention discloses a multifunctional heat treatment furnace, a use method of the multifunctional heat treatment furnace and a production line comprising the multifunctional heat treatment furnace, and relates to the technical field of steel pipe machining, in particular to an online heat treatment process of steel pipes. The interior of the furnace body is further divided into a plurality of hearths; the adjustable fire barrier is arranged, so that a small high-temperature area can be isolated in the hearth so as to meet the high-temperature requirement required in the online heat treatment quenching process, and when the quenching process is not needed, the height of the adjustable fire barrier can be adjusted, so that a quenching furnace or a tempering furnace is integrally formed in the hearth, and multiple purposes of one furnace are realized. The multifunctional heat treatment furnace can operate in two directions, one furnace can be arranged to be matched with two production lines at the same time when the capacity of a single production line cannot reach full load, then the service life of the heat treatment furnace is greatly prolonged, the equipment investment is reduced, and the cost of a heat treatment procedure is reduced.

Description

Technical Field

[0001] The present invention relates to the field of steel pipe processing equipment, and specifically to a multifunctional heat treatment furnace and a method for using the furnace and a production line including the furnace, in particular to an online heat treatment process for steel pipes. Background Art

[0002] In the steel pipe processing technology, heat treatment is an indispensable link to ensure the physical properties of the steel pipe. The heat treatment process of the steel pipe generally includes quenching, tempering, normalizing and annealing.

[0003] Quenching refers to heating the steel pipe to 30-50℃ (generally around 850℃~950℃) above Ac3 (the final temperature at which all free ferrite is transformed into austenite), keeping it warm for a period of time to make it fully or partially austenitized, and then cooling it to 600℃ or below at a cooling rate greater than the critical cooling rate to transform it into martensite (or bainite). Its purpose is to improve the mechanical properties of metal products or parts, such as improving the hardness and wear resistance of tools and bearings, improving the elastic limit of springs, and improving the comprehensive mechanical properties of shaft parts. Improve the material properties or chemical properties of some special steels, such as improving the corrosion resistance of stainless steel and increasing the permanent magnetism of magnetic steel. The insulation process before quenching is called soaking, the purpose of which is to make the overall temperature of the steel pipe more uniform. Low-grade steel pipes can also be directly quenched without soaking, and the soaking process is generally achieved in a quenching furnace.

[0004] Tempering is to heat the quenched steel pipe to 650℃ to 780℃, keep it warm for a certain period of time, and then slowly cool it in a certain way. The purpose is to reduce internal stress and reduce brittleness. Quenched parts have great stress and brittleness. If they are not tempered in time, they will often deform or even crack. Tempering is used to adjust the hardness, strength, plasticity and toughness to adjust the mechanical properties of the workpiece to meet the different performance requirements of various workpieces; the heating and heat preservation process is tempering, which is generally carried out in a tempering furnace.

[0005] Normalizing is to heat the steel pipe to Ac3+ (30-50℃), keep it warm for a period of time, and then cool it in the air (with water spray) to below 100℃ or to room temperature. The cooling speed is faster than annealing but lower than quenching. The purpose is to eliminate the banded structure in the rolled material and refine the grains. The heat preservation before normalizing is called soaking, just like the heat preservation before quenching, and is carried out in the quenching furnace.

[0006] Annealing is to heat the steel pipe to 650℃ to 780℃, and then slowly cool it, for example, as the furnace temperature decreases. After reaching the required temperature and time, the steel pipe is taken out of the furnace for air cooling, and also cooled to below 100℃ or to room temperature.

[0007] In order to heat treat steel pipes, steel pipe plants use dedicated heat treatment processes and online heat treatment processes: The dedicated heat treatment process is an offline process that can process low, medium and high-grade steel pipes. However, it requires a lot of equipment and a large initial investment in facilities. In addition, since it is an offline process, most steel pipes are at room temperature before quenching and need to be heated from room temperature to Ac3+ (30-50°C) in a quenching furnace. The energy consumption is high and the heat treatment cost is high. If the production load is not full, it is difficult to generate good economic benefits.

[0008] The online heat treatment process is divided into online normalizing treatment, online quenching treatment and online temperature-controlled cooling treatment; online normalizing treatment means that the rough pipe coming off the rolling line is air-cooled to about 600℃ to 650℃ on a small cooling bed, and then enters the reheating furnace (also a quenching furnace) to be reheated to Ac3+ (30~50℃), followed by subsequent high-pressure water descaling and sizing and reducing to obtain high-temperature finished pipes.

[0009] Online quenching means that the high-temperature finished tube (temperature at 850℃ and above) is stripped from the rolling line and enters the quenching furnace (heated to the required temperature in an induction furnace, resistance furnace or stepping furnace, etc., and is stable and uniform), followed by quenching treatment, collection, and then entering the offline tempering furnace to heat the finished tube to 600℃ to 700℃, and then air-cooling.

[0010] Online temperature control cooling refers to online water cooling of high-temperature finished pipes (850°C and above after the sizing mill). Note that the water cooling here only sprays water on the outer surface of the high-temperature finished pipe to reduce it to the required temperature (for example, the surface temperature is 500°C), and then enters the large cooling bed for air cooling to below 100°C or to room temperature.

[0011] In summary, since the online heat treatment process utilizes the temperature of the rough pipe itself and saves the energy consumption of heating from room temperature to 600℃ to 650℃, the cost of the heat treatment process is lower than that of the dedicated line.

[0012] However, online heat treatment still requires the configuration of different furnace bodies such as quenching furnaces and tempering furnaces, which take up a large space. When orders are not saturated, or when there are many small-batch and multi-specification production orders, the utilization rate of each furnace body is still very low. In addition, the existing online heat treatment processes all belong to a single process of heat treatment and cannot directly produce finished pipes. Summary of the invention

[0013] In view of the shortcomings of the above-mentioned prior art, the present invention provides a multifunctional heat treatment furnace to at least partially solve the technical problems mentioned in the background technology. The specific technical solution of the present invention to solve the above-mentioned technical problems is: A multifunctional heat treatment furnace comprises a third furnace, a fourth furnace, a second furnace, and a first furnace which are arranged in sequence; Burner settings: The first furnace is provided with a first burner; the second furnace is provided with a second burner near the first furnace; the third furnace is provided with a third burner; the fourth furnace is provided with a fourth burner near the third furnace; the first burner, the second burner, the third burner and the fourth burner are independently controlled; the independently controlled burners can flexibly adjust the temperature of each furnace according to different heat treatment requirements to meet diversified production requirements; Inlet and outlet settings: The first furnace is provided with a first roller feed and discharge line opening on the side away from the second furnace; the third furnace is provided with a second roller feed and discharge line opening on the side away from the fourth furnace; a bidirectional walking beam is provided between the first roller feed and discharge line opening and the second roller feed and discharge line opening for conveying steel pipes between the furnaces; Slag hopper and smoke exhaust port settings: The first furnace is provided with a first slag hopper and a first smoke exhaust port at the bottom of the side away from the second furnace; the third furnace is provided with a second slag hopper and a second smoke exhaust port at the bottom of the side away from the fourth furnace. The slag hopper is used to collect slag produced during the heat treatment process, and the smoke exhaust port is used to discharge combustion exhaust gas, guide the direction of air flow and control the temperature distribution in the furnace, to ensure environmental stability and safe production in the furnace. The first smoke exhaust port and the second smoke exhaust port are connected to a chimney, so they cannot be used at the same time. When the first smoke exhaust port is in use, the second smoke exhaust port is closed, and when the second smoke exhaust port is in use, the first smoke exhaust port is closed.

[0014] Compared with the prior art, this solution has the following beneficial effects: The heat treatment furnace of the present invention can be used in both directions, and can be used as a quenching furnace or a tempering furnace. In conjunction with a steel pipe conveyor line, it can serve two production lines at the same time, or be used as an online heat treatment furnace for one production line and as an offline heat treatment dedicated line. For production lines with many production specifications and unsaturated orders, one set of heat treatment furnace can be used to meet the processing requirements of two production lines, or when the production line does not need heat treatment, it can be used alone as an offline heat treatment furnace, which can greatly improve the utilization rate of the heat treatment furnace and reduce the cost of the heat treatment process.

[0015] Furthermore, a first adjustable fire baffle is provided between the first furnace and the second furnace, and the first adjustable fire baffle extends downward from the top of the furnace; a first push inlet and outlet line opening is provided on the side of the first adjustable fire baffle in the first furnace close to the first adjustable fire baffle; a second push inlet and outlet line opening is provided on the side of the second furnace close to the first adjustable fire baffle.

[0016] A second adjustable fire baffle is provided between the third furnace and the fourth furnace, and the second adjustable fire baffle extends downward from the top of the furnace; a third push inlet and outlet line opening is provided on the side of the third furnace close to the second adjustable fire baffle, and a fourth push inlet and outlet line opening is provided on the side of the fourth furnace close to the second adjustable fire baffle. The setting of the adjustable fire baffle can adjust the heat transfer and airflow distribution between the furnaces, thereby improving the heat treatment effect.

[0017] A first tube-passing inclined frame is detachably provided above the first push inlet and outlet opening or the second push inlet and outlet opening, and a second tube-passing inclined frame is detachably provided above the third push inlet and outlet opening or the fourth push inlet and outlet opening. The tube-passing inclined frame helps the smooth pushing and movement of steel pipes between different furnaces.

[0018] The walking beam includes an independently controlled first walking beam, a common walking beam, and a third walking beam; the first walking beam is arranged in the first furnace, the common walking beam is arranged in the second and fourth furnaces, and the third walking beam is arranged in the third furnace. The independently controlled walking beam can more accurately control the moving speed and position of the steel pipe in each furnace, thereby improving production efficiency and heat treatment quality.

[0019] The beneficial effect of adopting the above further scheme is that, since the soaking process before quenching and normalizing treatment requires the steel pipe to be heated to Ac3+ (30-50°C), and tempering and annealing require the steel pipe to be heated to 650°C to 780°C, the different temperature ranges make it generally necessary for the steel pipe factory to equip two independent heating furnaces, i.e., quenching furnace and tempering furnace, when performing heat treatment on the steel pipe to meet the requirements of different heating temperatures. The multifunctional heat treatment furnace of this scheme, part of the furnace body can be used as a quenching furnace, and part of the furnace body can be used as a tempering furnace, realizing multiple functions of one furnace body, and only one furnace can be set up to realize the functions of the previous quenching furnace and tempering furnace at the same time.

[0020] The present invention also discloses a method for using the multifunctional heat treatment furnace: When used as a single quenching furnace or tempering furnace: When used in the first direction: that is, when the steel pipe enters from the first furnace and exits from the third furnace, the third and fourth burners are working, and the first and second burners are closed; the first and second furnaces are used as preheating sections, the fourth furnace is used as heating section, and the third furnace is used as a soaking section. This setting can fully preheat the steel pipe before entering the heating section, improve heating efficiency and uniformity, and the soaking section ensures that the overall temperature of the steel pipe is uniform, improving the quality of heat treatment.

[0021] When used in the second direction: that is, when the steel pipe enters from the third furnace and exits from the first furnace, the third and fourth burners are closed, and the first and second burners are working; the third and fourth furnaces are used as preheating sections, the second furnace is used as heating sections, and the first furnace is used as soaking sections. By changing the working state of the burners and the functional allocation of each furnace, the two-way use of the heat treatment furnace is realized, which increases the flexibility of the equipment.

[0022] When a fire retaining wall is provided, part of the furnace of the heat treatment furnace of the present invention can be used as a quenching furnace, and part of the furnace can be used as a tempering furnace: When used in the first direction: the length of the first fire baffle wall in the furnace is lengthened, the length of the second fire baffle wall in the furnace is shortened, the first burner and the second burner are working, and the third burner and the fourth burner are closed; the first furnace is used as a quenching furnace, and the third furnace, the fourth furnace and the second furnace are used as tempering furnaces.

[0023] More specifically, the process of heat treatment of steel pipes based on a heat treatment furnace with a fire barrier wall is as follows: the high-temperature finished pipe is pushed into the first furnace from the first push-in and outfeed line port, the first step feed beam lifts the steel pipe and moves it toward the first roller inlet and outfeed line port, and when the steel pipe enters the first roller inlet and outfeed line port, the conveyor roller starts to send it out of the furnace.

[0024] The process of tempering the steel pipe is as follows: the steel pipe to be tempered enters the third furnace of the furnace from the second roller feed and discharge line port, and with the cooperation of the third stepping beam, the second pipe passing inclined frame and the common stepping beam, the steel pipe is moved toward the second push feed and discharge line port. When the steel pipe enters the second push feed and discharge line port, the push rod pushes the steel pipe out of the furnace.

[0025] When used in the second direction: the length of the first fire baffle wall in the furnace is shortened, and the length of the second fire baffle wall in the furnace is lengthened; the first burner and the second burner are closed, and the third burner and the fourth burner are working; the third furnace is used as a quenching furnace, and the first furnace, the second furnace, and the fourth furnace are used as tempering furnaces.

[0026] The process of heat treatment of steel pipes is as follows: the high-temperature finished pipe is pushed into the third furnace from the third push-in and outfeed line, the third stepping beam lifts the steel pipe and moves it toward the second roller inlet and outfeed line. When the steel pipe enters the second roller inlet and outfeed line, the conveyor roller starts to send it out of the furnace.

[0027] The process of tempering the steel pipe is as follows: the steel pipe to be tempered enters the first furnace of the furnace from the first roller feed and discharge line port, and with the cooperation of the first step feed beam, the first pipe inclined frame, and the common step beam, the steel pipe is moved toward the fourth push feed and discharge line port. When the steel pipe enters the fourth push feed and discharge line port, the push rod pushes the steel pipe out of the furnace.

[0028] The present invention also provides two steel pipe online heat treatment production lines: A multifunctional heat treatment furnace comprising at least one furnace without a fire retaining wall; The utility model relates to a multifunctional heat treatment furnace comprising at least one fire-blocking wall.

[0029] By rationally configuring the multifunctional heat treatment furnace, an efficient and flexible online heat treatment production line for steel pipes can be constructed to meet the needs of enterprises of different sizes and production requirements.

[0030] Beneficial effects of the present invention: Functional diversity: This multifunctional heat treatment furnace can be used flexibly in at least two directions. It can flexibly select the inlet and outlet directions of steel pipes according to the production site layout and process flow requirements, which improves the applicability of the equipment and the flexibility of production layout. And because it can be used in both directions, it can serve two production lines at the same time, improve the efficiency of the heat treatment furnace, and reduce the cost of the heat treatment process.

[0031] At the same time, the heat treatment furnace equipped with a fire barrier can be used as a single quenching furnace or tempering furnace, and can also realize the function of part of the furnace chamber as a quenching furnace and part of the furnace chamber as a tempering furnace. One device can meet a variety of heat treatment needs, reducing the company's investment in different types of heat treatment furnaces and reducing equipment purchase costs.

[0032] Precise temperature control: The burners of each furnace are independently controlled, and the setting of the adjustable fire baffle wall can optimize the heat distribution in the furnace and reduce energy consumption. According to different heat treatment process requirements, the temperature of each furnace can be accurately adjusted, which improves the stability of heat treatment quality and product performance and achieves the production goal of energy saving and environmental protection.

[0033] Flexible production line configuration: A variety of configuration solutions for online heat treatment production lines for steel pipes are provided. Enterprises can choose appropriate production line configurations based on their own production scale and needs, which improves the adaptability and economy of the production line. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the structure of a bidirectional multifunctional heat treatment furnace in the present invention; Figure 2 It is a schematic diagram of the structure of a multifunctional heat treatment furnace provided with a fire retaining wall in the present invention; Figure 3 This is a schematic diagram of the layout of a single production line + a dedicated heat treatment line including a bidirectional multifunctional heat treatment furnace; Figure 4 It is a schematic diagram of the layout of a double production line including a bidirectional multifunctional heat treatment furnace; Figure 5 This is a schematic diagram of the layout of a single production line + a dedicated heat treatment line including a multifunctional heat treatment furnace with a fire barrier; Figure 6 A schematic diagram of the dual production line layout including a multifunctional heat treatment furnace with a fire barrier.

[0035] In the accompanying drawings, the component names represented by the reference numerals are listed as follows: 101, first furnace; 102, second furnace; 103, third furnace; 104, fourth furnace; 201, first burner; 202, second burner; 203, third burner; 204, fourth burner; 301, first roller inlet and outlet; 302, second roller inlet and outlet; 303, first push inlet and outlet; 304, second push inlet and outlet; 305, third push inlet and outlet; 306, fourth push inlet and outlet; 401, first slag hopper; 402, second slag hopper; 403, first smoke exhaust port; 404, second smoke exhaust port; 501, first adjustable fire wall; 502, second adjustable fire wall; 601, first stepping beam; 602, common stepping beam; 603, third stepping beam; 607, loading platform; 608, No. 3 small cooling bed; 609, No. 4 small cooling bed; 610, No. 1 billet; 611, No. 1 piercing machine; 612, No. 1 pipe rolling mill; 613, No. 1 normalizing cooling bed; 614, No. 1 reheating furnace; 615, No. 1 small cooling bed; 616, No. 1 sizing mill; 617, No. 1 sawing; 618, No. 1 water cooling device; 619, No. 3 water cooling device; 620, No. 2 billet; 621, No. 2 piercing machine; 622, No. 2 tube rolling mill; 623, No. 2 normalizing cooling bed; 624, No. 2 reheating furnace; 625, No. 2 small cooling bed; 626, No. 2 sizing mill; 627, No. 2 sawing; 628, No. 2 water cooling device; 629, No. 4 water cooling device; 631. First two-way furnace; 632. Chain conveyor; 633. Normalizing cooling bed; 634. Second two-way furnace; 635. Two-way cooling bed; 636. Multifunctional walking furnace; 6110, the first intermediate cooling bed; 6111, the first straightening machine; 6112, the first large cooling bed; 6210, the second medium cooling bed; 6211, the second straightening machine; 6212, the second large cooling bed. DETAILED DESCRIPTION

[0036] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0037] Embodiment 1: like Figure 1 , which is a schematic diagram of the structure of a multifunctional heat treatment furnace, including a third furnace 103, a fourth furnace 104, a second furnace 102, and a first furnace 101 arranged in sequence; The first furnace 101 is provided with a first burner 201; the second furnace 102 is provided with a second burner 202 near the first furnace 101; the third furnace 103 is provided with a third burner 203; the fourth furnace 104 is provided with a fourth burner 204 near the third furnace 103; the first burner 201, the second burner 202, the third burner 203 and the fourth burner 204 are independently controlled; A first roller feed and discharge line opening 301 is provided on the side of the first furnace 101 away from the second furnace 102; a second roller feed and discharge line opening 302 is provided on the side of the third furnace 103 away from the fourth furnace 104; A first slag hopper 401 and a first smoke exhaust port 403 are provided at the bottom of the first furnace 101 away from the second furnace 102; The bottom of the third furnace 103 away from the fourth furnace 104 is provided with a second slag hopper 402 and a second smoke exhaust port 404; A bidirectional walking beam is provided between the first roller conveyor feed and discharge line opening 301 and the second roller conveyor feed and discharge line opening 302 .

[0038] This heat treatment furnace can be used as a single quenching furnace or tempering furnace. Its characteristic is that it can be used in both directions. Figure 1 In the direction shown, it can work in mode II (i.e., use in the second direction), with the steel pipe moving from left to right, or it can work in mode I (i.e., use in the first direction), with the steel pipe moving from right to left.

[0039] When the furnace operates in mode II, that is, the steel pipe enters from the third furnace 103 and exits from the first furnace 101, the third burner 203 and the fourth burner 204 are closed, and the first burner 201 and the second burner 202 are working; the third furnace 103 and the fourth furnace 104 are used as preheating sections, the second furnace 102 is used as a heating section, and the first furnace 101 is used as a uniform heating section.

[0040] When the furnace operates in mode I, that is, the steel pipe enters from the first furnace 101 and exits from the third furnace 103, the third burner 203 and the fourth burner 204 are in operation, and the first burner 201 and the second burner 202 are closed; the first furnace 101 and the second furnace 102 are used as preheating sections, and the fourth furnace 104 is used as a heating section; the third furnace 103 is used as a uniform heating section.

[0041] The bidirectional movable beam runs through the four furnaces to realize the continuous transportation of steel pipes. In each step of transportation, the steel pipes are rolled and flipped at a certain angle to avoid collapse and bending of the steel pipes due to being at one angle for a long time.

[0042] In this scheme, if Figure 1As shown, there are two smoke exhaust ports, a first smoke exhaust port 403 and a second smoke exhaust port 404, but the two smoke exhaust ports are connected to the same chimney, so the two smoke exhaust ports cannot be used at the same time. When one smoke exhaust port is opened, the other smoke exhaust port must be in a closed state. Specifically, when the furnace works in mode I, that is, when the steel pipe moves from right to left, the first smoke exhaust port 403 is opened and the second smoke exhaust port 404 is closed; when the furnace works in mode II, that is, when the steel pipe moves from left to right, the first smoke exhaust port 403 is closed and the second smoke exhaust port 404 is opened, so that the steel pipe can gradually move from the low temperature zone to the high temperature zone.

[0043] Embodiment 2: like Figure 2 As shown, it is a multifunctional heat treatment furnace with a fire retaining wall, which can be used as a single tempering furnace or a quenching furnace, or part of the furnace chamber can be used as a tempering furnace and part of the furnace chamber can be used as a quenching furnace, and it can be used in both directions; The furnace is an integral walking furnace in appearance, and the interior of the furnace is divided into four parts, namely the third furnace 103, the fourth furnace 104, the second furnace 102, and the first furnace 101; The first furnace 101 is provided with a first burner 201; the second furnace 102 is provided with a second burner 202 near the first furnace 101; the third furnace 103 is provided with a third burner 203; the fourth furnace 104 is provided with a fourth burner 204 near the third furnace 103; The first adjustable fire baffle 501 is disposed between the second furnace 102 and the first furnace 101, and the second adjustable fire baffle 502 is disposed between the third furnace 103 and the fourth furnace 104, and both the first adjustable fire baffle 501 and the second adjustable fire baffle 502 extend downward from the top of the furnace.

[0044] A first roller feed and discharge line opening 301 is provided on the side of the first furnace 101 away from the second furnace 102, a first push feed and discharge line opening 303 is provided on the side of the first furnace 101 close to the first adjustable fire baffle 501, and a second push feed and discharge line opening 304 is provided on the side of the second furnace 102 close to the first adjustable fire baffle 501; a second roller feed and discharge line opening 302 is provided on the side of the third furnace 103 away from the fourth furnace 104, a third push feed and discharge line opening 305 is provided on the side of the third furnace 103 close to the second adjustable fire baffle 502, and a fourth push feed and discharge line opening 306 is provided on the side of the fourth furnace 104 close to the second adjustable fire baffle 502; A first stepping beam 601 is provided at the bottom of the first furnace 101; a third stepping beam 603 is provided at the bottom of the third furnace 103; a common stepping beam 602 is provided in the second furnace 102 and the fourth furnace 104; The first tube-passing inclined frame is detachably disposed above the first push inlet and outlet line opening 303 or the second push inlet and outlet line opening 304 , and the second tube-passing inclined frame is detachably disposed above the third push inlet and outlet line opening 305 or the fourth push inlet and outlet line opening 306 .

[0045] When used as a simple quenching furnace or tempering furnace, Figure 2 In the direction shown, when the steel pipe moves from the third furnace 103 to the first furnace 101, the furnace is said to be working in mode II: In this working mode, the third push inlet and outlet line port 305 and the second push inlet and outlet line port 304 are not used; the third furnace 103 and the fourth furnace 104 together constitute the preheating section II, the second furnace 102 constitutes the heating section II, and the first furnace 101 constitutes the soaking section II. The second tube-passing inclined frame is pushed onto the third push inlet and outlet line port 305, and the first tube-passing inclined frame is pushed onto the second push inlet and outlet line port 304, and then: The steel pipes fed in from the second roller feed and discharge line opening 302 are gradually placed on the second tube-passing inclined frame by the third stepping beam 603, and the steel pipes roll from the second tube-passing inclined frame to the trough of the fourth push feed and discharge line opening 306, and the common stepping beam 602 moves the steel pipes in the trough of the fourth push feed and discharge line opening 306 to the second push feed and discharge line opening 304, and finally places the steel pipes on the first tube-passing inclined frame, and the steel pipes roll from the first tube-passing inclined frame to the trough of the first push feed and discharge line opening 303, and the first stepping beam 601 then moves the steel pipes in the trough of the first push feed and discharge line opening 303 to the first roller feed and discharge line opening 301, and when the steel pipes are placed on the first roller feed and discharge line opening 301, they are transported out of the furnace by the first roller feed and discharge line opening 301.

[0046] When the steel pipe moves in the reverse direction, that is, from the first furnace 101 to the third furnace 103, the furnace is said to be operating in mode I: In this working mode, the first push inlet and outlet line port 303 and the fourth push inlet and outlet line port 306 are not used. Figure 2 As shown, the steel pipe moves from right to left: at this time, the first furnace 101 and the second furnace 102 together constitute the preheating section I, the fourth furnace 104 constitutes the heating section I, and the third furnace 103 constitutes the equalizing section I. The first tube-passing inclined frame is pushed to the first push-in and outfeed line port 303, and the second tube-passing inclined frame is pushed to the fourth push-in and outfeed line port 306; the transportation direction of the steel pipe is exactly opposite to that of working mode II, but the principle is the same and will not be repeated here.

[0047] In this embodiment, two adjustable fire baffles are provided, namely, the first adjustable fire baffle 501 between the first furnace 101 and the second furnace 102 and the second adjustable fire baffle 502 between the third furnace 103 and the fourth furnace 104. By adjusting the height of the fire baffles, the temperature of different furnaces can be controlled, so that part of the furnace of the heat treatment furnace can be used as a quenching furnace and part of the furnace can be used as a tempering furnace. When implementing the soaking quenching + tempering, soaking normalizing + tempering, soaking normalizing processes, the length of the fire baffle on the soaking zone side in the furnace should be increased until it reaches the bottom of the furnace, and the length of the adjustable fire baffle on the low temperature side in the furnace should be shortened, so that the heating chamber in the furnace can strengthen the gathering of high-temperature furnace gas; The pipe inlet and outlet openings, also known as pipe inlet and outlet routing openings in the industry, or simply openings, are set to six in this embodiment, namely the first roller inlet and outlet opening 301, the second roller inlet and outlet opening 302, the first push inlet and outlet opening 303, the second push inlet and outlet opening 304, the third push inlet and outlet opening 305, and the fourth push inlet and outlet opening 306; the first roller inlet and outlet opening 301 and the second roller inlet and outlet opening 302 are for roller conveying steel pipes; the first push inlet and outlet opening 303, the second push inlet and outlet opening 304, the third push inlet and outlet opening 305, and the fourth push inlet and outlet opening 306 are for pushing or ejecting steel pipes with a push rod.

[0048] The multifunctional heat treatment furnace used in this scheme has the following advantages: On the one hand, waste heat is utilized. One furnace has the working modes of equalizing + tempering and tempering of high-temperature finished pipes at the same time, making full use of the waste heat of high-temperature pipes and the waste heat of high-temperature furnace gas when the furnace equalizes the high-temperature steel pipes. Therefore, the heating cost is lower, the investment is more economical, and there is no need to set up other additional equalizing furnaces.

[0049] Embodiment 3: like Figure 3 As shown, it is a schematic diagram of the layout of a single production line + a dedicated heat treatment line including a bidirectional multifunctional heat treatment furnace. This production line includes two bidirectional multifunctional heat treatment furnaces, one of which is called the first bidirectional furnace 631, which is used as a quenching furnace, and the other bidirectional multifunctional heat treatment furnace is called the second bidirectional furnace 634, which is used as a tempering furnace. For low-end and medium-end steel pipes, online heat treatment processes can be performed, specifically: After being pierced by the No. 1 piercing machine 611, the No. 1 billet 610 is rolled by the No. 1 tube rolling mill 612. The No. 1 normalizing cooling bed 613, the No. 1 reheating furnace 614, and the No. 1 small cooling bed 615 are reserved for conventional online heat treatment and can actually be omitted in this embodiment.

[0050] The rolled steel pipe enters the No. 1 sizing mill 616 for sizing. The temperature of the high-temperature finished pipe after the No. 1 sizing mill 616 is about 850°C. It is then divided into two processes according to the steel pipe processing requirements: process A or process B.

[0051] Process A is in the rolling state, which is equivalent to the direct normalizing treatment of the steel pipe. At this time, the steel pipe after the No. 1 sizing mill 616 directly enters the first intermediate cooling bed 6110 along the a1 line, is air-cooled in the first intermediate cooling bed 6110 to complete the normalizing treatment, then enters the first straightening machine 6111 for straightening, and then enters the first large cooling bed 6112 for cooling, and obtains the finished pipe after finishing output; Process B is an online heat treatment process. The steel pipe enters the No. 1 saw 617 to saw the double-length steel pipe into a single-length steel pipe (the "single-length" here refers to the GB / T 5310-2023 "Seamless Steel Pipe for High-Pressure Boiler" which stipulates that the length of the steel pipe is generally 4 to 12 meters, so the industry generally calls a 12-meter-long steel pipe a single-length steel pipe and a 24-meter-long steel pipe a double-length steel pipe. The reason why the double-length steel pipe is sawed into a single-length steel pipe here is that the size of the furnace body itself should not be too large to meet the heat treatment of the single-length steel pipe). If it is a single-length steel pipe, no sawing is required, and then enter one of the following heat treatment processes: Online soaking quenching + tempering process: The high-temperature finished pipe enters the chain conveyor 632, advances to the b1 line, and enters the first two-way furnace 631 along the b1 line for uniform heating. After uniform heating, it is discharged from the furnace along the b2 line and enters the fourth water cooling device 629 for quenching. In this example, the b1 line and the b2 line correspond to the first roller inlet and outlet line port 301 or the second roller inlet and outlet line port 302 of the first two-way furnace 631, respectively. Then, it enters the normalizing cooling bed 633 (the normalizing cooling bed 633 has strong wind and water mist cooling functions, which are only used when normalizing is required). Continue Go to line c2, enter the second two-way furnace 634 along line c2 for tempering treatment, go to line c1, exit the furnace along line c1. In this example, line c1 and line c2 correspond to the first roller inlet and outlet 301 or the second roller inlet and outlet 302 of the second two-way furnace 634 respectively, enter the first intermediate cooling bed 6110, and after the steel pipe is cooled to the required temperature, enter the first straightening machine 6111 for straightening. Then the steel pipe enters the first large cooling bed 6112, air-cooled to below 100°C, and enters the next process. Online soaking normalizing + tempering process: The high-temperature finished pipe enters the chain conveyor 632, advances to the b2 line, and enters the first two-way furnace 631 along the b2 line for uniform heating. After uniform heating, it is discharged from the furnace along the b1 line, crosses the No. 3 water cooling device 619 (the water cooling device can be arranged in three dimensions), enters the normalizing cooling bed 633, and then continues to advance to the c2 line, enters the second two-way furnace 634 along the c2 line for tempering, advances to the c1 line, discharges from the furnace along the c1 line and enters the first intermediate cooling bed 6110, and the subsequent process is the same as the online uniform heating quenching + tempering process; Online soaking and normalizing process: The high-temperature finished pipe enters the chain conveyor 632, advances to the b1 line, and enters the first two-way furnace 631 for uniform heating along the b1 line. After uniform heating, it is discharged from the furnace along the b2 line, crosses the No. 4 water cooling device 629, enters the normalizing cooling bed 633, advances to the d1 line, and enters the first intermediate cooling bed 6110 along the d1 line. The subsequent process is the same as the online uniform heating quenching + tempering process; Online direct quenching + tempering process: The high-temperature finished pipes are quenched along the e1 line in the No. 1 water cooling device 618, and then enter the normalizing cooling bed 633, advance to the c2 line, enter the second two-way furnace 634 along the c2 line for tempering, advance to the c1 line, exit the furnace along the c1 line, and then enter the first intermediate cooling bed 6110. The subsequent process is the same as the online soaking quenching + tempering process; Online direct normalizing + tempering process: The high-temperature finished pipes follow the e1 line, cross the No. 1 water cooling device 618, and then go through the online direct quenching + tempering process; Online direct normalizing process: same as the above process A; The above is based on the online heat treatment process of this production line. This production line can also adapt to the offline processing mode of high-end pipes, as follows: The steel pipes sawn into single lengths are stored on the loading platform 607 and transported to the processing line by the loading platform 607. Specifically, one of the following off-line heat treatment processes is performed: Offline soaking quenching + tempering process: The high-temperature finished pipe enters the chain conveyor 632 from the loading platform 607, advances to the b2 line, and enters the first two-way furnace 631 along the b2 line for uniform heating. After uniform heating, it is discharged from the furnace along the b1 line, enters the No. 3 water cooling device 619 for quenching, and then enters the normalizing cooling bed 633, advances to the c1 line, enters the second two-way furnace 634 along the c1 line for tempering, advances to the c2 line, and discharges from the furnace along the c2 line, and then enters the second intermediate cooling bed 6210. After the steel pipe is cooled to the required temperature, it enters the second straightening machine 6211 for straightening, and then enters the second large cooling bed 6212, air-cooled to below 100°C, and enters the next process; Offline soaking normalizing + tempering process: The high-temperature finished pipe enters the chain conveyor 632 through the loading platform 607, advances to the b1 line, enters the first two-way furnace 631 along the b1 line for soaking, and after soaking, it is discharged from the furnace along the b2 line, crosses the No. 4 water cooling device 629, enters the normalizing cooling bed 633, advances to the c1 line, enters the second two-way furnace 634 along the c1 line for tempering, advances to the c2 line, and is discharged from the furnace along the c2 line and enters the second intermediate cooling bed 6210, and the subsequent steps are the same as the aforementioned offline soaking quenching + tempering process; Offline soaking and normalizing: The high-temperature finished pipe enters the chain conveyor 632, advances to the b2 line, and enters the first two-way furnace 631 along b2 for equalization. After equalization, it is discharged from the furnace along the b1 line, crosses the No. 4 water cooling device 629, enters the normalizing cooling bed 633, advances to the d2 line, and enters the second intermediate cooling bed 6210 along the d2 line. The subsequent process is the same as the aforementioned offline equalization quenching + tempering process.

[0052] Embodiment 4: like Figure 4 As shown, it is a schematic diagram of a dual production line layout including a bidirectional multifunctional heat treatment furnace. This production line layout can meet the production needs of two production lines. Especially when one production line cannot produce at full capacity, using one set of heat treatment system to adapt to two production lines can improve the utilization rate of the heat treatment system.

[0053] The production line above the figure is Line I, and its workflow is as follows: The process before the sizing machine is the same as that in Example 3, and will not be described in detail here. The temperature of the high-temperature finished pipe after the No. 1 sizing machine 616 is about 850° C., and then enters the A process or the B process; A process is rolling state: The steel pipe directly enters the first intermediate cooling bed 6110 along the a1 line for air cooling, then enters the first straightening machine 6111 for straightening, enters the first large cooling bed 6112 for cooling, and then is finished to produce the finished product; Process B requires online heat treatment: The steel pipe enters the No. 1 sawing 617, which saws the double-length steel pipe into a single-length steel pipe; if it is a single-length steel pipe, no sawing is required; then it enters one of the following heat treatment processes: Soaking quenching + tempering: The high-temperature finished pipe enters the chain conveyor 632, advances to the b1 line, enters the first two-way furnace 631 along the b1 line for uniform heating, and after uniform heating, it is discharged from the furnace along the b2 line, enters the No. 4 water cooling device 629 for quenching treatment, enters the normalizing cooling bed 633, advances to the c2 line, and enters the second two-way furnace 634 along the c2 line for tempering treatment. The steel pipe advances to the c1 line, is discharged from the furnace along the c1 line and enters the first intermediate cooling bed 6110. When the steel pipe is cooled to the required temperature, it enters the first straightening machine 6111 for straightening, and then enters the first large cooling bed 6112. After air cooling to below 100°C, it enters the next process; Normalizing + tempering: The high-temperature finished pipe enters the chain conveyor 632, advances to the b2 line, and enters the first two-way furnace 631 along the b2 line for equalization. After equalization, it is discharged from the furnace along the b1 line, crosses the No. 3 water cooling device 619, enters the normalizing cooling bed 633, advances to the c2 line, enters the second two-way furnace 634 along the c2 line for tempering, advances to the c1 line, and is discharged from the furnace along the c1 line and enters the first intermediate cooling bed 6110. The steel pipe is cooled to the required temperature and enters the first straightening machine 6111 for straightening, and then enters the first large cooling bed 6112. After air cooling to below 100°C, it enters the next process; Normalizing: The high-temperature finished pipe enters the chain conveyor 632, advances to the b1 line, and enters the first two-way furnace 631 along the b1 line for equalization. After equalization, it is discharged from the furnace along the b2 line, crosses the No. 4 water cooling device 629, enters the normalizing cooling bed 633, advances to the d1 line, and enters the first intermediate cooling bed 6110 along the d1 line. When the steel pipe is cooled to the required temperature, it enters the first straightening machine 6111 for straightening, and then enters the first large cooling bed 6112. After air cooling to below 100°C, it enters the next process; Direct quenching + tempering: The high-temperature finished pipes are quenched in the No. 1 water cooling device 618 along the e1 line, and then enter the normalizing cooling bed 633, advance to the c2 line, enter the second two-way furnace 634 along the c2 line for tempering, advance to the c1 line, and enter the first intermediate cooling bed 6110 along the c1 line. After the steel pipes are cooled to the required temperature, they enter the first straightening machine 6111 for straightening, and then enter the first large cooling bed 6112. After air cooling to below 100°C, they enter the next process; Direct normalizing + tempering: The high-temperature finished pipes go along the e1 line, cross the No. 1 water cooling device 618, enter the normalizing cooling bed 633, advance to the c2 line, enter the second two-way furnace 634 for tempering along the c2 line, advance to the c1 line, exit the furnace along the c1 line and enter the first intermediate cooling bed 6110. After the steel pipes are cooled to the required temperature, they enter the first straightening machine 6111 for straightening, and then enter the first large cooling bed 6112. After air cooling to below 100°C, they enter the next process; The process of direct normalizing is the same as that of process A above; For the lower line II, the No. 2 billet 620 is pierced by the No. 2 piercing machine 621 and then rolled by the No. 2 tube rolling mill 622. The No. 2 normalizing cooling bed 623, the No. 2 reheating furnace 624, and the No. 2 small cooling bed 625 are also equipment reserved for conventional online heat treatment and can also be omitted in this embodiment.

[0054] Specifically, the workflow of line II is as follows: The temperature of the high-temperature finished pipe after the No. 2 sizing and reducing mill 626 is about 850℃, and then enters the A process or B process; A process is rolling state: The steel pipe directly enters the second intermediate cooling bed 6210 along line a2 for air cooling to complete normalizing, then enters the second straightening machine 6211 for straightening treatment, enters the second large cooling bed 6212, is cooled to below 100℃, and is output after finishing; Process B is an online heat treatment process: The steel pipe enters the second sawing 627, which saws the double-length steel pipe into a single-length steel pipe. If the steel pipe is already a single-length steel pipe, no sawing is required. Then, according to the process requirements, one of the following processes is entered: Soaking quenching + tempering: The high-temperature finished pipe enters the chain conveyor 632, advances to the b2 line, and enters the first two-way furnace 631 along the b2 line for equalization. After equalization, it is discharged from the furnace along the b1 line, enters the No. 3 water cooling device 619 for quenching, enters the normalizing cooling bed 633, advances to the c1 line, enters the second two-way furnace 634 along the c1 line for tempering, advances to the c2 line, and enters the second intermediate cooling bed 6210 along the c2 line. After the steel pipe is cooled to the required temperature, it enters the second straightening machine 6211 for straightening, and then enters the second large cooling bed 6212. After air cooling to below 100°C, it enters the next process; Normalizing + tempering: The high-temperature finished pipe enters the chain conveyor 632, advances to the b1 line, and enters the first two-way furnace 631 along the b1 line for equalization. After equalization, it is discharged from the furnace along the b2 line, crosses the fourth water cooling device 629, enters the normalizing cooling bed 633, advances to the c1 line, enters the second two-way furnace 634 along the c1 line for tempering, advances to the c2 line, and is discharged from the furnace along the c2 line and enters the second intermediate cooling bed 6210. After the steel pipe is cooled to the required temperature, it enters the second straightening machine 6211 for straightening, and then enters the second large cooling bed 6212. After air cooling to below 100°C, it enters the next process; Normalizing: The high-temperature finished pipe enters the chain conveyor 632, advances to the b2 line, enters the first two-way furnace 631 along b2 for equalization, and after equalization, exits the furnace along the b1 line, crosses the No. 4 water cooling device 629, enters the normalizing cooling bed 633, advances to the d2 line, and enters the second intermediate cooling bed 6210 along the d2 line. After the steel pipe cools to the required temperature, it enters the second straightening machine 6211 for straightening, and then enters the second large cooling bed 6212. After air cooling to below 100°C, it enters the next process; Direct quenching + tempering: The high-temperature finished pipes are quenched in the No. 2 water cooling device 628 along the e2 line, and then enter the normalizing cooling bed 633, advance to the c1 line, enter the second two-way furnace 634 along the c1 line for tempering, advance to the c2 line, and exit the furnace along the c2 line and enter the second intermediate cooling bed 6210. After the steel pipes are cooled to the required temperature, they enter the second straightening machine 6211 for straightening, and then enter the second large cooling bed 6212, air-cooled to below 100°C, and enter the next process; Direct normalizing + tempering: The high-temperature finished pipes go along the e2 line, cross the second water cooling device 628, enter the normalizing cooling bed 633 for normalizing, advance to the c1 line, enter the second two-way furnace 634 for tempering, advance to the c2 line, exit the furnace along the c2 line and enter the second intermediate cooling bed 6210. After the steel pipes are cooled to the required temperature, they enter the second straightening machine 6211 for straightening, and then enter the second large cooling bed 6212. After air cooling to below 100°C, they enter the next process; The process of direct normalizing is the same as that of process A above.

[0055] Embodiment 5: like Figure 5 As shown, it is a schematic diagram of the layout of a single production line including a multifunctional heat treatment furnace provided with a fire retaining wall; Similarly, the process before the sizing machine is the same as that in Example 3, and will not be described in detail. The high-temperature finished pipe after the No. 1 sizing machine 616 is about 850°C, and then enters the A process or the B process; A process is rolling state: The steel pipe directly enters the first intermediate cooling bed 6110 along the a1 line for air cooling and normalizing, then enters the first straightening machine 6111, the first large cooling bed 6112, and finally finished output; Process B is an online heat treatment process: Enter the No. 1 sawing 617 to saw the multi-length steel pipe into a single-length steel pipe. If it is a single-length steel pipe, no sawing is required; then enter one of the following heat treatment processes: Soaking quenching + tempering: The high-temperature finished pipe enters the No. 4 small cooling bed 609 along the b1 line, and then along the e1 line to send the steel pipe to the entrance of the multifunctional walking furnace 636. The e1 line corresponds to the first push inlet and outlet line port 303. The high-temperature finished pipe enters the high-temperature equalizing zone of the multifunctional walking furnace 636. After equalizing, it is discharged from the furnace along the c1 line. The c1 line corresponds to the first roller inlet and outlet line port 301, and enters the No. 1 water cooling device 618 for quenching treatment. After cooling to the required temperature, the steel pipe enters the bidirectional cooling bed 635 along the d1 line. It is sent to the c2 line at the entrance of the multifunctional walking furnace 636, and the c2 line corresponds to the second roller feed and discharge line port 302. After the steel pipe is heated and tempered in the low temperature zone of the multifunctional walking furnace 636, it is discharged from the furnace along the f1 line, and the f1 line corresponds to the second push feed and discharge line port 304, and enters the first intermediate cooling bed 6110. The steel pipe is cooled to the required temperature and enters the first straightening machine 6111 for straightening treatment. The steel pipe enters the first large cooling bed 6112, is cooled to below 100°C, and enters the next process; Normalizing + tempering: The high-temperature finished pipe enters the No. 4 small cooling bed 609 along the b1 line, and then along the e1 line, the steel pipe is sent to the entrance of the multifunctional walking furnace 636. The high-temperature finished pipe enters the high-temperature equalizing zone of the multifunctional walking furnace 636 for equalizing, and then is discharged from the furnace along the c1 line. The steel pipe enters the two-way cooling bed 635 along the d1 line for normalizing. After air cooling to the required temperature, it is sent to the c2 line at the entrance of the multifunctional walking furnace 636. After the steel pipe is heated and tempered in the low-temperature zone of the furnace, it is discharged from the furnace along the f1 line and enters the first intermediate cooling bed 6110. The steel pipe is cooled to the required temperature and enters the first straightening machine 6111 for straightening treatment. The steel pipe enters the first large cooling bed 6112, is cooled to below 100°C, and enters the next process; Normalizing: The high-temperature finished pipe enters the No. 4 small cooling bed 609 along the b1 line, and then along the e1 line, the steel pipe is sent to the entrance of the multifunctional walking furnace 636. The high-temperature finished pipe enters the high-temperature equalizing zone of the multifunctional walking furnace 636. After equalizing, it is discharged from the furnace along the c1 line and enters the first intermediate cooling bed 6110 for normalizing treatment. The steel pipe is cooled to the required temperature and enters the first straightening machine 6111 for straightening treatment. The steel pipe enters the first large cooling bed 6112, is cooled to below 100°C, and enters the next process; Direct quenching + tempering: The high-temperature finished pipe passes through the b1 line and enters the first water cooling device 618 for quenching treatment. After cooling to the required temperature, the steel pipe enters the two-way cooling bed 635 along the d1 line and is sent to the c2 line at the entrance of the multifunctional step furnace 636. After the steel pipe is heated and tempered in the low-temperature zone of the furnace, it is taken out of the furnace along the c1 line and enters the first intermediate cooling bed 6110. The steel pipe is cooled to the required temperature and enters the first straightening machine 6111 for straightening. Then, it enters the first large cooling bed 6112, cools to below 100°C, and enters the next process. Direct normalizing + tempering: The high-temperature finished pipe enters the bidirectional cooling bed 635 for normalizing, air-cooling to 500-650℃, and the steel pipe is sent to the entrance c2 line of the multifunctional walking furnace 636. The steel pipe enters the low-temperature zone of the multifunctional walking furnace 636, and gradually moves to the high-temperature zone to achieve heating and tempering. After being heated to the required temperature, it is discharged from the furnace along the c1 line. The steel pipe enters the first intermediate cooling bed 6110. The steel pipe is cooled to the required temperature and enters the first straightening machine 6111 for straightening treatment. The steel pipe enters the first large cooling bed 6112, cools to below 100℃, and enters the next process; The process flow of direct normalizing is the same as that of process A above and will not be repeated here.

[0056] This production line is also suitable for offline heat treatment line processes: Figure 5 Show the following part: Soaking quenching + tempering: The finished pipe at room temperature enters the third small cooling bed 608 from the loading platform 607 along the b2 line, and then along the e2 line to send the steel pipe to the entrance of the multifunctional walking furnace 636. The e2 line corresponds to the third push inlet and outlet line port 305. The high-temperature finished pipe enters the high-temperature equalizing zone of the multifunctional walking furnace 636. After equalizing, it is discharged from the furnace along the c2 line and enters the second water cooling device 628 for quenching. After cooling to the required temperature, the steel pipe enters the two-way cooling bed 635 along the d2 line and is sent to the entrance c1 line of the multifunctional walking furnace 636. After the steel pipe is heated and tempered in the low-temperature zone of the furnace, it is discharged from the furnace along the f2 line. The f2 line corresponds to the fourth push inlet and outlet line port 306 and enters the second intermediate cooling bed 6210. The steel pipe is cooled to the required temperature and enters the second straightening machine 6211 for straightening. Then it enters the second large cooling bed 6212, air-cooled to below 100°C, and enters the next process. Normalizing + tempering: The high-temperature finished pipe enters the No. 3 small cooling bed 608 along the b2 line, and then along the e2 line, the steel pipe is sent to the entrance of the multifunctional walking furnace 636. The high-temperature finished pipe enters the high-temperature equalizing zone of the multifunctional walking furnace 636. After equalizing, it is discharged from the furnace along the c2 line. The steel pipe enters the two-way cooling bed 635 along the d2 line for normalizing. After air cooling to the required temperature, it is sent to the entrance c1 line of the multifunctional walking furnace 636. After the steel pipe is heated and tempered in the furnace, it is discharged from the furnace along the f2 line and enters the second intermediate cooling bed 6210. The steel pipe is cooled to the required temperature and enters the second straightening machine 6211 for straightening. Then it enters the second large cooling bed 6212, air-cooled to below 100°C, and enters the next process. Normalizing: The high-temperature finished pipe enters the No. 3 small cooling bed 608 along the b2 line, and then along the e2 line, the steel pipe is sent to the entrance of the multifunctional walking furnace 636. The high-temperature finished pipe enters the high-temperature equalizing zone of the multifunctional walking furnace 636. After equalizing, it is discharged from the furnace along the c2 line and enters the second intermediate cooling bed 6210 for normalizing. The steel pipe is cooled to the required temperature and enters the second straightening machine 6211 for straightening. Then it enters the second large cooling bed 6212, air-cooled to below 100°C, and enters the next process. Direct quenching + tempering: The high-temperature finished pipe passes through the b2 line and enters the second water cooling device 628 for quenching. After cooling to the required temperature, the steel pipe enters the two-way cooling bed 635 along the d2 line and is sent to the c1 line at the entrance of the multifunctional step furnace 636. After the steel pipe is heated and tempered in the low-temperature zone of the furnace, it is discharged from the furnace along the c2 line and enters the second intermediate cooling bed 6210 for normalizing. After the steel pipe cools to the required temperature, it enters the second straightening machine 6211 for straightening, and then enters the second large cooling bed 6212 for air cooling to below 100°C and enters the next process; Direct normalizing + tempering: The high-temperature finished pipe enters the bidirectional cooling bed 635 for normalizing, air-cooling to 500 to 650°C, and sends the steel pipe to the entrance c1 line of the multifunctional walking furnace 636. The steel pipe enters the low-temperature zone of the multifunctional walking furnace 636, and gradually moves to the high-temperature zone to achieve tempering. After being heated to the required temperature, it is discharged from the furnace along the c2 line. The steel pipe enters the second intermediate cooling bed 6210, cools to the required temperature, enters the second straightening machine 6211 for straightening, and then enters the second large cooling bed 6212, air-cooling to below 100°C, and enters the next process; The process steps of direct normalizing are the same as those of process A and will not be repeated here.

[0057] Embodiment 6: like Figure 6 As shown, it is a schematic diagram of the dual production line layout including a multifunctional heat treatment furnace with a fire barrier. One furnace can meet the production needs of both production lines I and II. Similarly, when a single production line cannot run at full capacity, a set of heat treatment system is used to adapt to the two production lines. The heat treatment system can only serve one production line at the same time and cannot serve two production lines at the same time.

[0058] For the production of Line I located at the top of the diagram: The high-temperature finished pipe after the No. 1 sizing and reducing mill 616 generally has a temperature of 850℃ or above, and may then enter process A or process B; A process is rolling state: The steel pipe is normalized in the first intermediate cooling bed 6110, then passes through the first straightening machine 6111, and then enters the first large cooling bed 6112 to be cooled to below 100°C, and then is finished and output; Process B is a heat treatment process: The steel pipe enters the No. 1 sawing 617. If it is a multi-length steel pipe, it will be sawn into a single length to adapt to the size of the heat treatment furnace; if it is a single length, it does not need to be sawed and passes directly; then it enters one of the following processes: Soaking quenching + tempering: The high-temperature finished pipe enters the No. 4 small cooling bed 609 along the b1 line, and then along the e1 line, the steel pipe is sent to the entrance of the multifunctional walking furnace 636. The high-temperature finished pipe enters the high-temperature equalizing zone (corresponding to the equalizing section) of the multifunctional walking furnace 636. After equalizing, it is discharged from the furnace along the c1 line and enters the No. 1 water cooling device 618 for quenching. After cooling to the required temperature, the steel pipe enters the two-way cooling bed 635 along the d1 line and is sent to the c2 line at the entrance of the multifunctional walking furnace 636. After the steel pipe is tempered in the low-temperature zone (corresponding to the preheating section and the heating section) in the multifunctional walking furnace 636, it is discharged from the furnace along the f1 line and enters the first intermediate cooling bed 6110. The steel pipe is cooled to the required temperature and enters the first straightening machine 6111. The steel pipe enters the first large cooling bed 6112, air-cooled to below 100°C, and enters the next process; Normalizing + tempering: The high-temperature finished pipe enters the No. 4 small cooling bed 609 along the b1 line, and then along the e1 line, the steel pipe is sent to the entrance of the multifunctional walking furnace 636, enters the high-temperature equalizing zone of the multifunctional walking furnace 636, and after equalizing, it is discharged from the furnace along the c1 line. The steel pipe enters the two-way cooling bed 635 along the d1 line for normalizing. After air cooling to the required temperature, it is sent to the c2 line at the entrance of the multifunctional walking furnace 636. After the steel pipe is tempered in the low-temperature zone of the multifunctional walking furnace 636, it is discharged from the furnace along the f1 line and enters the first intermediate cooling bed 6110. The steel pipe is cooled to the required temperature and enters the first straightening machine 6111. The steel pipe enters the first large cooling bed 6112, air-cooled to below 100°C, and enters the next process; Normalizing: The high-temperature finished pipe enters the No. 4 small cooling bed 609 along the b1 line, and then along the e1 line, the steel pipe is sent to the entrance of the multifunctional walking furnace 636. The high-temperature finished pipe enters the high-temperature equalizing zone of the multifunctional walking furnace 636. After equalizing, it is discharged from the furnace along the c1 line and enters the first intermediate cooling bed 6110 for normalizing. The steel pipe is cooled to the required temperature and enters the first straightening machine 6111. The steel pipe enters the first large cooling bed 6112, air-cooled to below 100°C, and enters the next process; Direct quenching + tempering: The high-temperature finished pipe passes through the b1 line and enters the first water cooling device 618 for quenching. After cooling to the required temperature, the steel pipe enters the two-way cooling bed 635 along the d1 line and is sent to the c2 line at the entrance of the multifunctional step furnace 636. After tempering in the low-temperature zone of the furnace, the steel pipe is discharged from the furnace along the c1 line and enters the first intermediate cooling bed 6110. After the steel pipe cools to the required temperature, it enters the first straightening machine 6111, and the steel pipe enters the first large cooling bed 6112, air-cooled to below 100°C, and enters the next process; Direct normalizing + tempering: The high-temperature finished pipe enters the bidirectional cooling bed 635 for normalizing, air-cooling to 500-650℃, and sends the steel pipe to the entrance c2 line of the multifunctional walking furnace 636. The steel pipe enters the low-temperature zone of the multifunctional walking furnace 636 and gradually moves to the high-temperature equalizing zone to complete tempering. After being heated to the required temperature, it is discharged from the furnace along the c1 line, and the steel pipe enters the first intermediate cooling bed 6110. The steel pipe is cooled to the required temperature and enters the first straightening machine 6111. The steel pipe enters the first large cooling bed 6112, air-cooling to below 100℃, and enters the next process; The direct normalizing process is the same as the aforementioned process A; For the production of Line II shown below: Similarly, the high-temperature finished pipe after the No. 2 sizing mill 626 is around 850℃, and then enters process A or process B: A process is rolling state: The steel pipe directly enters the second intermediate cooling bed 6210 along the a2 line for air cooling, then enters the second straightening machine 6211, and is fully cooled on the second large cooling bed 6212 before being finished to produce finished pipes; Process B is an online heat treatment process: The steel pipe enters the second saw cut 627 and then enters one of the following heat treatment processes: Soaking quenching + tempering: The high-temperature finished pipe enters the No. 3 small cooling bed 608 along the b2 line, and then along the e2 line, the steel pipe is sent to the entrance of the multifunctional walking furnace 636. The high-temperature finished pipe enters the high-temperature equalizing zone of the multifunctional walking furnace 636. After equalizing, it is discharged from the furnace along the c2 line and enters the No. 2 water cooling device 628 for quenching. After cooling to the required temperature, the steel pipe enters the two-way cooling bed 635 along the d2 line and is sent to the entrance c1 line of the multifunctional walking furnace 636. After the steel pipe is tempered in the low-temperature zone of the multifunctional walking furnace 636, it is discharged from the furnace along the f2 line and enters the second intermediate cooling bed 6210 for air cooling, and then enters the second straightening machine 6211, and then cooled to below 100°C on the second large cooling bed 6212, and enters the next process; Normalizing + tempering: The high-temperature finished pipe enters the No. 3 small cooling bed 608 along the b2 line, and then along the e2 line, the steel pipe is sent to the entrance of the multifunctional walking furnace 636, enters the high-temperature equalizing zone of the multifunctional walking furnace 636, and after equalizing, it is discharged from the furnace along the c2 line. The steel pipe enters the two-way cooling bed 635 along the d2 line for normalizing. After air cooling to the required temperature, it is sent to the c1 line at the entrance of the multifunctional walking furnace 636. After tempering in the low-temperature zone of the multifunctional walking furnace 636, the steel pipe is discharged from the furnace along the f2 line, enters the second intermediate cooling bed 6210 for air cooling, and then enters the second straightening machine 6211, and then cools to below 100°C on the second large cooling bed 6212, and enters the next process; Normalizing: The high-temperature finished pipe enters the No. 3 small cooling bed 608 along the b2 line, and then along the e2 line, the steel pipe is sent to the entrance of the multifunctional walking furnace 636. The high-temperature finished pipe enters the high-temperature equalizing zone of the multifunctional walking furnace 636. After equalizing, it is discharged from the furnace along the c2 line and enters the second intermediate cooling bed 6210 for air cooling, and then enters the second straightening machine 6211, and then cools to below 100°C on the second large cooling bed 6212, and enters the next process; Direct quenching + tempering: The high-temperature finished pipe passes through line b2 and enters the second water cooling device 628 for quenching. After cooling to the required temperature, the steel pipe enters the two-way cooling bed 635 along line d2 and is sent to the entrance line c1 of the multifunctional walking furnace 636. After tempering in the low-temperature zone of the multifunctional walking furnace 636, the steel pipe is discharged from the furnace along line c2 and enters the second intermediate cooling bed 6210 for air cooling, then enters the second straightening machine 6211, and then cools to below 100°C on the second large cooling bed 6212 to enter the next process; Direct normalizing + tempering: The high-temperature finished pipe enters the bidirectional cooling bed 635 for normalizing, air-cooling to 500-650℃, and then the steel pipe is sent to the entrance c1 line of the multifunctional walking furnace 636. The steel pipe enters the low-temperature zone of the multifunctional walking furnace 636 and gradually moves to the high-temperature zone to complete tempering. After being heated to the required temperature, it is discharged from the furnace along the c2 line and enters the second intermediate cooling bed 6210 for air cooling, then enters the second straightening machine 6211, and then cools to below 100℃ on the second large cooling bed 6212 to enter the next process; The process of direct normalizing is the same as step A above.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A multifunctional heat treatment furnace, characterized in that: It comprises a third furnace (103), a fourth furnace (104), a second furnace (102), and a first furnace (101) which are arranged in sequence; A first burner (201) is provided in the first furnace (101); a second burner (202) is provided in the second furnace (102) near the first furnace (101); a third burner (203) is provided in the third furnace (103); a fourth burner (204) is provided in the fourth furnace (104) near the third furnace (103); the first burner (201), the second burner (202), the third burner (203) and the fourth burner (204) are independently controlled; A first roller conveyor inlet and outlet opening (301) is provided on the side of the first furnace (101) away from the second furnace (102); a second roller conveyor inlet and outlet opening (302) is provided on the side of the third furnace (103) away from the fourth furnace (104); A bidirectional walking beam is provided between the first roller conveyor inlet and outlet opening (301) and the second roller conveyor inlet and outlet opening (302); A first slag hopper (401) and a first smoke exhaust port (403) are provided at the bottom of the first furnace (101) away from the second furnace (102); A second slag hopper (402) and a second smoke exhaust port (404) are provided at the bottom of the third furnace (103) on a side away from the fourth furnace (104).

2. The multifunctional heat treatment furnace according to claim 1, characterized in that: A first adjustable fire baffle (501) is provided between the first furnace (101) and the second furnace (102), and the first adjustable fire baffle (501) extends downward from the top of the furnace; a first push inlet and outlet line opening (303) is provided on the side of the first furnace (101) close to the first adjustable fire baffle (501); and a second push inlet and outlet line opening (304) is provided on the side of the second furnace (102) close to the first adjustable fire baffle (501); A second adjustable fire baffle (502) is provided between the third furnace (103) and the fourth furnace (104), and the second adjustable fire baffle (502) extends downward from the top of the furnace; a third push inlet and outlet line opening (305) is provided on the side of the third furnace (103) close to the second adjustable fire baffle (502), and a fourth push inlet and outlet line opening (306) is provided on the side of the fourth furnace (104) close to the second adjustable fire baffle (502); A first tube-passing inclined frame is detachably provided above the first push inlet and outlet line opening (303) or the second push inlet and outlet line opening (304), and a second tube-passing inclined frame is detachably provided above the third push inlet and outlet line opening (305) or the fourth push inlet and outlet line opening (306); The walking beam comprises an independently controlled first walking beam (601), a common walking beam (602), and a third walking beam (603); the first walking beam (601) is arranged in a first furnace (101), the common walking beam (602) is arranged in the second furnace (102) and the fourth furnace (104); and the third walking beam (603) is arranged in a third furnace (103).

3. A method for using the multifunctional heat treatment furnace according to claim 1 or 2, characterized in that: Used as a single quenching furnace or tempering furnace: When used in the first direction, that is, when the steel pipe enters the first furnace and exits the third furnace (103), the third burner (203) and the fourth burner (204) are in operation, and the first burner (201) and the second burner (202) are closed; the first furnace (101) and the second furnace (102) are used as preheating sections, and the fourth furnace (104) is used as a heating section; and the third furnace (103) is used as a soaking section; When used in the second direction, that is, when the steel pipe enters from the third furnace (103) and exits from the first furnace (101), the third burner (203) and the fourth burner (204) are closed, and the first burner (201) and the second burner (202) are in operation; the third furnace (103) and the fourth furnace (104) are used as a preheating section, the second furnace (102) is used as a heating section, and the first furnace (101) is used as a soaking section.

4. The method for using the multifunctional heat treatment furnace according to claim 3, characterized in that: Part of the furnace is used as a quenching furnace, and part of the furnace is used as a tempering furnace; When used in the first direction, the length of the first fire baffle wall in the furnace is lengthened, the length of the second fire baffle wall in the furnace is shortened, the first burner (201) and the second burner (202) are in operation, and the third burner (203) and the fourth burner (204) are closed; the first furnace (101) is used as a quenching furnace, and the third furnace (103), the fourth furnace (104) and the second furnace (102) are used as a tempering furnace; When used in the second direction, the length of the first fire baffle wall in the furnace is shortened, and the length of the second fire baffle wall in the furnace is lengthened; the first burner (201) and the second burner (202) are closed, and the third burner (203) and the fourth burner (204) are in operation; the third furnace (103) is used as a quenching furnace, and the first furnace (101), the second furnace (102), and the fourth furnace (104) are used as tempering furnaces.

5. The method for using the multifunctional heat treatment furnace according to claim 4, characterized in that: When used in the first direction, the process of performing a heat treatment on the steel pipe is as follows: the high-temperature finished pipe is pushed into the first furnace (101) from the first push feed line opening (303), the first step feed beam (601) lifts the steel pipe and moves it toward the first roller feed line opening (301), and when the steel pipe enters the first roller feed line opening (301), the conveyor roller starts to send it out of the furnace; The process of tempering the steel pipe is as follows: the steel pipe to be tempered enters the third furnace (103) of the furnace from the second roller feed and discharge line port (302), and the steel pipe is moved toward the second push feed and discharge line port (304) under the cooperation of the third stepping beam (603), the second pipe passing inclined frame, and the common stepping beam (602). When the steel pipe enters the second push feed and discharge line port (304), the push rod pushes the steel pipe out of the furnace.

6. The method for using the multifunctional heat treatment furnace according to claim 4, characterized in that: When used in the second direction, the process of performing heat treatment on the steel pipe is as follows: the high-temperature finished pipe is pushed into the third furnace (103) from the third push feed and discharge line opening (305), the third stepping beam (603) lifts the steel pipe and moves it toward the second roller feed and discharge line opening (302), and when the steel pipe enters the second roller feed and discharge line opening (302), the conveying roller starts to send it out of the furnace; The process of tempering the steel pipe is as follows: the steel pipe to be tempered enters the first furnace (101) of the furnace from the first roller feed and discharge line port (301), and with the cooperation of the first stepping beam (601), the first pipe passing inclined frame, and the common stepping beam (602), the steel pipe is moved toward the fourth push feed and discharge line port (306). When the steel pipe enters the fourth push feed and discharge line port (306), the push rod pushes the steel pipe out of the furnace.

7. A steel pipe online heat treatment production line, characterized in that: It comprises at least one multifunctional heat treatment furnace as claimed in claim 1.

8. A steel pipe online heat treatment production line, characterized in that: It comprises at least one multifunctional heat treatment furnace as claimed in claim 2.

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