Heat treatment furnace for duplex stainless steel

Abstract

The invention discloses a heat treatment furnace for duplex stainless steel. The heat treatment furnace comprises a placement platen, a pull rope and a bunching structure, the placing bedplate is placed on the trolley, the connecting hooks arranged at the two ends of the pull rope are respectively hooked with the hanger arranged on the placing bedplate, and the bunching structure is arranged on the pull rope; the bunching structure comprises a bunching block, a screw rod, a connecting plate, an abutting block A and a nut; a hook is fixed to the top of the bunching block, and the pull rope penetrates through a rope hole formed in the bunching block. The screw rod is fixed to the bottom of the bunching block, the connecting plate is arranged on the screw rod in a sleeving mode and located at the bottom of the bunching block, the nut is connected to the screw rod in a threaded mode and abuts against the connecting plate, and the abutting blocks A sequentially penetrate through a plurality of penetrating holes formed in the bottom of the bunching block. The device has the advantages of efficient batch processing of workpieces, temperature uniformity guarantee and stable hoisting.

Description

Technical Field

[0001] This invention relates to the field of metal processing technology, specifically to a heat treatment furnace for duplex stainless steel. Background Technology

[0002] Duplex stainless steel is renowned for its exceptional strength and excellent corrosion resistance, particularly against pitting and stress corrosion cracking. The term "duplex" refers to its microstructure, which consists of approximately 50% austenite (γ) and 50% ferrite (α) phases.

[0003] Double solution heat treatment is an advanced heat treatment process specifically designed for duplex stainless steels, especially super duplex and premium duplex stainless steels. Its core purpose is to optimize and stabilize the duplex microstructure, ensuring the material achieves optimal overall performance, particularly corrosion resistance and toughness. During manufacturing processes (such as welding and hot forming) or when held within a certain temperature range (approximately 300°C to 1000°C), duplex stainless steel undergoes the precipitation of various harmful secondary phases in its microstructure. These phases primarily include: Sigma phase: A hard and brittle intermetallic compound rich in chromium and molybdenum. It is one of the most harmful phases, severely degrading the toughness and corrosion resistance of materials.

[0004] Chi phase: Similar in properties to σ phase, it is also a harmful phase.

[0005] Nitrogen compounds (such as) ): When precipitated at grain boundaries or phase boundaries, it consumes the surrounding chromium, leading to a decrease in local corrosion resistance.

[0006] A single standard solution treatment is unlikely to simultaneously and effectively eliminate different harmful phases precipitated in all temperature ranges. Dual solution treatment addresses these issues by performing two solution treatment stages at different temperatures.

[0007] The core device for dual solution treatment is a heat treatment furnace, which can be a trolley-type furnace with a movable "trolley" at the bottom. During loading, the trolley is moved out of the furnace, and the workpiece is hoisted onto it by an overhead crane. The trolley then enters the furnace for heating. When removing the workpiece for quenching, a crane and lifting equipment are used to place the workpiece on a sturdy pallet or base, and the lifting equipment directly lifts the entire pallet. This is very effective for irregularly shaped workpieces that are difficult to hang directly.

[0008] However, when processing a large number of workpieces at once, hoisting them one by one for quenching takes a lot of time. Unquenched workpieces are exposed to the elements, causing their temperature to drop. The temperature difference between workpieces quenched at different times directly affects the quenching effect. Furthermore, after the hoisting rope is connected to the overhead crane hook, the midpoint of the hoisting rope is not fixed, resulting in poor hoisting stability.

[0009] In view of this, we propose a heat treatment furnace for duplex stainless steel. Summary of the Invention

[0010] The purpose of this invention is to provide a heat treatment furnace for duplex stainless steel to solve the problems mentioned in the background art.

[0011] To achieve the above objectives, the present invention provides the following technical solution: a heat treatment furnace for duplex stainless steel, comprising a trolley that travels inside and outside the bottom of the furnace box and a door fixed to the pull end of the trolley, wherein the door and the opening end of the furnace box can be closed, and further comprising a placement platform, a pull rope and a wire harness structure. The placement platform is placed on the trolley, and the connecting hooks at both ends of the pull rope are respectively connected to the hanging frame on the placement platform. The wire harness structure is set on the pull rope. The wire harness structure includes a wire harness block, a screw, a connecting plate, a stop block A, and a nut; A hook is fixed to the top of the cable bundle, and a pull rope passes through a rope hole opened on the cable bundle. In the suspended state: the middle of the pull rope inside the cable tie block is upward and its two sides are downward, and the cable tie block restricts the movement of the pull rope inside it; The screw is fixed to the bottom of the wire harness block, the connecting plate is sleeved on the screw and the connecting plate is located at the bottom of the wire harness block, the nut is threaded onto the screw and the nut abuts against the connecting plate, and several abutment blocks A pass through several through holes opened at the bottom of the wire harness block in sequence; In the suspended state: Block A abuts against the pull rope inside the cable bundle block.

[0012] Preferably, the abutting end of the abutting block A is provided with an abutting groove A, which is arc-shaped and abuts against the inclined end of the pull rope located in the cable bundle block.

[0013] Preferably, several of the abutment blocks A are stacked and distributed along the longitudinal central axis of the rope hole, and the height of the multiple abutment blocks A varies in a stepped manner.

[0014] Preferably, a gap is left between the connecting plate and the bottom of the wire harness block.

[0015] Preferably, the connecting plate has a stop block B fixed at both ends, and the top of the stop block B has a stop groove B. The stop groove B is arc-shaped and abuts against the bottom of the pull rope extending out of the rope hole.

[0016] Preferably, the arc surface of the abutment groove B is inclined outward and downward.

[0017] Preferably, a limiting frame is fixed on the trolley, the inner wall of the limiting frame is inclined to form an inverted trapezoidal cavity, and the outer wall of the placement platform is inclined, with its bottom forming an inverted trapezoidal body.

[0018] Compared with the prior art, the beneficial effects of the present invention are: High-efficiency batch processing: By placing a platform to lift multiple workpieces at once, the workpiece transfer time is significantly shortened, avoiding the temperature difference between workpieces before and after the traditional single lifting method, and ensuring the consistency of quenching quality.

[0019] Temperature uniformity guaranteed: Rapid overall hoisting reduces the exposure time of the workpiece to air, effectively preventing the workpiece temperature from dropping, which is especially suitable for temperature-sensitive duplex stainless steel materials.

[0020] Stable hoisting: The cable harness structure forms a triple protection through V-shaped limiting, multi-point positioning of stop block A, and anti-slip mechanism of stop block B, solving the technical problem of the midpoint of the pull rope not being fixed in traditional hoisting.

[0021] Adaptive adjustment capability: The stepped distribution of abutment blocks A can hold the pull rope in place, while the adjustable design of the nut allows the position of the connecting plate to be adjusted according to actual working conditions, optimizing the constraint effect. Furthermore, the position of the harness block on the pull rope can be adjusted to accommodate possible changes in the lifting midpoint. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the wire harness structure installation of the present invention; Figure 3 This is an exploded view of the wire harness structure of the present invention; Figure 4 This is a schematic cross-sectional view of the wire harness structure of the present invention under normal conditions; Figure 5 This is a cross-sectional view of the wire bundle structure under extrusion conditions according to the present invention; Figure 6 This is a cross-sectional view of the wire harness structure in the loosened state according to the present invention; Figure 7 This is a schematic cross-sectional view of the wire harness block of the present invention; Figure 8 This is a schematic diagram of the placement platform of the present invention.

[0023] In the diagram: 100, furnace box; 200, trolley; 300, box door; 400, limiting frame; 500, placement platform; 600, hanging bracket; 700, connecting hook; 800, pull rope; 900, wire harness structure; 901. Cable bundle; 902. Screw; 903. Connecting plate; 904. Abutment block A; 905. Nut; 906. Abutment block B; 907. Hook; 9011, Rope hole; 9012, Perforation; 9041, Counter-trough A; 9061, Counter-trough B. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] A heat treatment furnace for duplex stainless steel, please refer to Figures 1 to 8 It includes a furnace box 100, a trolley 200, a box door 300, a limiting frame 400, a placement platform 500, a hanging rack 600, a connecting hook 700, a pull rope 800, and a wire harness structure 900. The trolley 200 travels inside and outside the bottom of the furnace box 100. The box door 300 is fixed to the pull-out end of the trolley 200 and can be closed with the open end of the furnace box 100. The pull-out end of the trolley 200 can be connected to an external push-pull machine, which provides power for the trolley 200 to move. The placement plate 500 is placed on the trolley 200 to support the duplex stainless steel workpiece to be processed. A limit frame 400 is fixed on the trolley 200, the inner wall of which is inclined to form an inverted trapezoidal cavity, while the outer wall of the placement plate 500 is correspondingly inclined, forming an inverted trapezoidal body at the bottom. This matching structure ensures the stable positioning of the placement plate 500 on the trolley 200 and prevents it from moving during the movement of the trolley 200.

[0026] The pull rope 800 has connecting hooks 700 at both ends, which are respectively hooked to the hanging brackets 600 set on the placement platform 500. The cable tie structure 900 is set on the pull rope 800.

[0027] The cable harness structure 900 includes a cable harness block 901, a screw 902, a connecting plate 903, a stop block A 904, a nut 905, a stop block B 906, and a hook 907. The hook 907 is fixed to the top of the cable harness block 901 for connection to an overhead crane or hoist. A pull rope 800 passes through a rope hole 9011 on the cable harness block 901. The screw 902 is fixed to the bottom of the cable harness block 901. The connecting plate 903 is sleeved on the screw 902 and located at the bottom of the cable harness block 901. The nut 905 is threaded onto the screw 902 and abuts against the connecting plate 903, thereby fixing the position of the connecting plate 903. A gap is left between the connecting plate 903 and the bottom of the cable harness block 901 to allow for some adjustment space.

[0028] In the suspended state, the pull rope 800 naturally forms a V-shape within the cable tie block 901, with its middle end facing upwards and both sides downwards. This V-shaped arrangement, combined with the internal structure of the cable tie block 901, significantly increases the contact area and friction between the pull rope 800 and the cable tie block 901. The rope hole 9011 allows the pull rope 800 to pass freely while generating sufficient frictional resistance under stress, effectively preventing accidental slippage of the pull rope 800 during hoisting.

[0029] Several abutment blocks A904 pass sequentially through the through holes 9012 at the bottom of the cable tie block 901. In the suspended state, rotating the nut 905 moves the connecting plate 903 toward the bottom of the cable tie block 901, causing the abutment blocks A904 to press against the pull rope 800 inside the cable tie block 901. The abutment end of the abutment block A904 has an arc-shaped abutment groove A9041. This arc-shaped design perfectly matches the cylindrical shape of the pull rope 800, increasing the contact area and avoiding stress concentration. The multiple abutment blocks A904 are symmetrically distributed around the longitudinal central axis of the rope hole 9011, with their height varying in a stepped manner. This arrangement can accommodate the V-shaped angle of the pull rope 800, achieving multi-point, uniform constraint on the pull rope 800 and effectively preventing lateral swaying of the pull rope 800.

[0030] Abutment blocks B906 are fixed at both ends of the connecting plate 903. The abutment groove B9061 at the top of the abutment block B906 is arc-shaped, with the arc surface tilted outwards and downwards. This unique design allows the abutment block B906 to move with the connecting plate 903 while the abutment block A904 abuts against the pull rope 800 in the suspended state. The abutment block B906 generates an upward force against the pull rope 800 through the abutment groove B9061, forming a vertically misaligned constraint force with the suspended pull rope 800 at the point where it extends out of the cable tie block 901. This mechanical arrangement not only further stabilizes the pull rope 800, but more importantly, effectively prevents the risk of the pull rope 800 slipping out of the cable tie structure 900.

[0031] Workflow: Phase 1: Loading and Primary Heating The duplex stainless steel workpieces to be processed are neatly arranged on the placement platform 500. The trolley 200 is pulled out from the bottom of the furnace chamber 100 by an external push-pull machine, and the placement platform 500 carrying the workpieces is hoisted onto the trolley 200 by an overhead crane. The trapezoidal bottom of the placement platform 500 mates with the trapezoidal cavity of the limiting frame 400 to achieve precise positioning. The trolley 200, carrying the workpieces, drives into the furnace chamber 100, the chamber door 300 closes, and the heating elements of the furnace chamber 100 activate, initiating a heating process.

[0032] Phase Two: Rapid Lifting and Initial Quenching After heat treatment, the trolley 200 is removed from the furnace. The overhead crane and hook 907 are connected to the wire harness structure 900. The connecting hooks 700 at both ends of the pull rope 800 are quickly hooked to the hanger 600 on the platform 500. When lifting begins, the wire harness structure 900 automatically activates. The pull cord 800 forms a stable V-shaped structure within the cable tie block 901.

[0033] Rotate nut 905, and connecting plate 903 moves toward the bottom of cable bundle 901. Abutment block A904 presses against the pull rope 800 inside cable bundle 901 to prevent slippage.

[0034] Block B906 acts synchronously to hold the pull rope 800 in place, creating a staggered constraint force.

[0035] The entire placement platform 500 and all workpieces are lifted at once and quickly transferred to the quenching medium.

[0036] Phase 3: Reset Preparation After quenching, the placement plate 500 is hoisted back onto the trolley 200, and the connecting hook 700 is removed to prepare for the next round of heat treatment.

[0037] Fourth stage: Secondary heating The trolley 200 carries the workpiece into the furnace box 100, the box door 300 is closed, and the heating components of the furnace box 100 start the secondary heating process.

[0038] Fifth stage: Secondary quenching In the second stage, the entire placement platform 500 and all workpieces are lifted out and quickly transferred to the quenching medium.

[0039] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A heat treatment furnace for duplex stainless steel, comprising a trolley (200) running in the bottom of a furnace chamber (100) and a chamber door (300) fixed to the pulling end of the trolley (200), the chamber door (300) being closable to the opening end of the furnace chamber (100), characterized in that: It also includes a placing platform (500), a pull rope (800) and a binding structure (900); The placing platform (500) is placed on the trolley (200), the connecting hooks (700) provided at the two ends of the pull rope (800) are respectively hooked with the hanging racks (600) provided on the placing platform (500), and the binding structure (900) is provided on the pull rope (800); The binding structure (900) comprises a binding block (901), a screw rod (902), a connecting plate (903), a resisting block A (904) and a nut (905); The hook (907) is fixed at the top of the binding block (901), and the pull rope (800) passes through the rope hole (9011) provided in the binding block (901); In the lifting state, the middle end of the pull rope (800) in the binding block (901) is upward, and the two sides are downward, and the binding block (901) limits the movement of the pull rope (800) in it; The screw rod (902) is fixed at the bottom of the binding block (901), the connecting plate (903) is sleeved on the screw rod (902), and the connecting plate (903) is located at the bottom of the binding block (901), the nut (905) is threadedly connected on the screw rod (902), and the nut (905) abuts against the connecting plate (903), and the plurality of resisting blocks A (904) pass through the plurality of through holes (9012) provided at the bottom of the binding block (901) in sequence; In the lifting state, the resisting block A (904) abuts against the pull rope (800) in the binding block (901).

2. The heat treatment furnace for duplex stainless steel according to claim 1, characterized in that: The abutting end of the resisting block A (904) is provided with a resisting groove A (9041), the resisting groove A (9041) is arc-shaped, and the resisting groove A (9041) is in abutting cooperation with the inclined end of the pull rope (800) in the binding block (901).

3. A heat treatment furnace for duplex stainless steel according to claim 2, characterized in that: The plurality of resisting blocks A (904) are distributed in the longitudinal central axis of the rope hole (9011), and the heights of the plurality of resisting blocks A (904) change in a stepped manner.

4. The heat treatment furnace for duplex stainless steel according to claim 1, characterized in that: The connecting plate (903) and the bottom of the binding block (901) are provided with a gap.

5. The heat treatment furnace for duplex stainless steel according to claim 3, characterized in that: The two ends of the connecting plate (903) are respectively fixed with the resisting block B (906), the top end of the resisting block B (906) is provided with the resisting groove B (9061), the resisting groove B (9061) is arc-shaped, and the resisting groove B (9061) is in abutting cooperation with the bottom of the pull rope (800) extending out of the rope hole (9011).

6. A heat treatment furnace for duplex stainless steel according to claim 5, characterized in that: The arc surface of the resisting groove B (9061) is outwardly inclined and downwardly arranged.

7. The heat treatment furnace for duplex stainless steel according to claim 1, characterized in that: The trolley (200) is fixed with a limiting frame (400), the inner wall of the limiting frame (400) is inclined to form an inverted trapezoidal cavity, and the outer wall of the placing platform (500) is inclined, and the bottom thereof forms an inverted trapezoidal body.

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