Anti-caking long-life molten iron ladle stirring head

Abstract

This utility model discloses an anti-slag-caking, long-life molten iron ladle stirring head, belonging to the technical field of iron and steel metallurgical equipment. It aims to solve the problems of easy slag formation and short lifespan of existing molten iron ladle stirring heads. The stirring head includes a stirring shaft and stirring blades. The stirring blades are spirally distributed on the outside of the stirring shaft, and the blade surface has raised guide ridges that can change the direction of molten iron flow and reduce slag adhesion and accumulation. A connecting flange is provided at the top of the stirring shaft, with bolt holes for easy quick assembly and disassembly with the drive device, improving maintenance convenience. The stirring shaft and stirring blade substrate are made of high-chromium-nickel heat-resistant steel, possessing excellent high-temperature strength and corrosion resistance. The working surface of the blades is coated with a wear-resistant, anti-slag-caking coating using plasma spraying technology, further isolating slag erosion and enhancing wear resistance. Simultaneously, the surface of the stirring head undergoes sandblasting, preheating, and slow cooling processes to ensure a stable bond between the coating and the substrate, preventing cracking.

Description

Technical Field

[0001] This utility model relates to the field of iron and steel metallurgical equipment technology, specifically to an anti-slag-caking, long-life molten iron ladle stirring head. Background Technology

[0002] In iron and steel metallurgical production, molten iron pretreatment is a crucial step, and the ladle agitator is a key piece of equipment in this process. Its main function is to agitate the molten iron, ensuring that impurities are fully reacted and removed. However, existing ladle agitators suffer from two major problems during use:

[0003] Easy to slag: When molten iron is at high temperature, the slag in it easily adheres to the surface of the stirring head and forms slag. As the usage time increases, the slag will gradually thicken, which will not only increase the stirring resistance of the stirring head and reduce the stirring efficiency, but also cause uneven heating of the stirring head, affecting the pretreatment effect of molten iron.

[0004] Short lifespan: On the one hand, the high temperature of molten iron will cause strong thermal shock and corrosion to the stirring head, leading to cracks, wear and other damage. On the other hand, the cleaning process after slag formation will damage the surface of the stirring head, further shortening its service life. Existing stirring heads usually need to be replaced every 1-2 months. Frequent replacements not only increase equipment purchase costs but also affect production progress.

[0005] Therefore, this utility model provides an anti-slagging, long-life molten iron ladle stirring head to solve the above problems. Utility Model Content

[0006] To address the shortcomings of existing technologies, this invention provides an anti-slagging, long-life molten iron ladle stirring head, which solves the aforementioned problems.

[0007] To achieve the above objectives, this utility model provides the following technical solution: an anti-slagging, long-life molten iron ladle stirring head, comprising a stirring shaft and stirring blades, wherein the stirring blades are evenly distributed spirally on the outer side of the stirring shaft, and the spiral angle of the stirring blades is 30°-45°; the surface of the stirring blades is provided with several guide ridges extending along their length, the spacing between adjacent guide ridges is 20mm-30mm, and the height of the guide ridges is 5mm-8mm; the base material of the stirring shaft and stirring blades is... The high-chromium-nickel heat-resistant steel has the following chemical composition (mass fraction): C 0.20%-0.30%, Cr 20%-25%, Ni 10%-15%, Si 0.8%-1.2%, Mn 0.5%-1.0%, Mo 1.5%-2.0%, N 0.10%-0.15%, with the remainder being Fe; the working surface of the stirring blade is provided with a wear-resistant and anti-slagging coating with a thickness of 0.5mm-1.0mm, and the wear-resistant and anti-slagging coating material is WC-Co alloy.

[0008] Furthermore, the wear-resistant and anti-slag coating is prepared using plasma spraying technology, with a spraying current of 120A-150A, an arc voltage of 25V-30V, and a spraying speed of 5mm / s-8mm / s.

[0009] Furthermore, the surface of the stirring head (including the stirring shaft and stirring blades) is sandblasted with 80-120 mesh brown corundum and the sandblasting pressure is 0.5MPa-0.8MPa.

[0010] Furthermore, the stirring head is preheated before spraying the wear-resistant and anti-slag coating, with a preheating temperature of 300℃-400℃ and a holding time of 1h-2h; after spraying the wear-resistant and anti-slag coating, it is slowly cooled, with a cooling rate of 50℃ / h-100℃ / h.

[0011] Furthermore, a connecting flange is fixedly provided at the top of the stirring shaft, and 4-6 evenly distributed bolt holes are provided on the connecting flange, with the diameter of the bolt holes being 16mm-20mm.

[0012] Furthermore, the connecting flange and the stirring shaft are integrally cast structures, the thickness of the connecting flange is 20mm-30mm, and the outer diameter of the connecting flange is 50mm-80mm larger than the outer diameter of the stirring shaft.

[0013] Beneficial effects

[0014] This invention provides an anti-slagging, long-life molten iron ladle stirring head. Compared with the prior art, it has the following advantages:

[0015] 1. This anti-slag, long-life molten iron ladle stirring head, through the structural design of spiral stirring blades and guide ribs, changes the flow state of molten iron and slag, reducing the adhesion and accumulation of slag on the surface of the stirring head; at the same time, the wear-resistant and anti-slag coating can effectively isolate the slag from the contact between the slag and the stirring head substrate, further reducing the probability of slag formation.

[0016] 2. This anti-slagging, long-life molten iron ladle stirring head features a high-chromium-nickel heat-resistant steel substrate with excellent high-temperature performance, capable of withstanding high-temperature erosion from molten iron. The wear-resistant and anti-slagging coating enhances the stirring head's wear resistance and corrosion resistance, significantly reducing equipment replacement frequency and production costs. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a perspective view of the external structure of this utility model;

[0019] Figure 2 This is the utility model Figure 1 Enlarged view of the structure at point A in the middle;

[0020] Figure 3 This is a three-dimensional view of the bottom structure of this utility model.

[0021] In the diagram: 1. Stirring shaft; 2. Stirring blades; 3. Guide ribs; 4. Connecting flange; 5. Bolt holes; 6. Wear-resistant and anti-slagging coating. Detailed Implementation

[0022] It should be noted that in the description of the embodiments of this application, the terms "front," "rear," "left," "right," "up," "down," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. The terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0023] The present application will be further described in detail below with reference to the accompanying drawings and embodiments.

[0024] Reference Figures 1 to 3 This application provides an anti-slagging, long-life molten iron ladle stirring head, comprising a stirring shaft 1 and stirring blades 2. The stirring blades 2 are evenly distributed in a spiral shape on the outer side of the stirring shaft 1, and the spiral angle of the stirring blades 2 is 30°-45°. The surface of the stirring blades 2 is provided with a plurality of guide ribs 3 extending along their length direction, the spacing between adjacent guide ribs 3 is 20mm-30mm, and the height of the guide ribs 3 is 5mm-8mm. The base material of the stirring shaft 1 and the stirring blades 2 is a high-chromium nickel resistant... The hot steel has the following chemical composition by mass fraction: C 0.20%-0.30%, Cr 20%-25%, Ni 10%-15%, Si 0.8%-1.2%, Mn 0.5%-1.0%, Mo 1.5%-2.0%, N 0.10%-0.15%, with the remainder being Fe; the working surface of the stirring blade 2 is provided with a wear-resistant and anti-slagging coating 6, the thickness of which is 0.5mm-1.0mm, and the material of the wear-resistant and anti-slagging coating 6 is WC-Co alloy.

[0025] The wear-resistant and anti-slag-caking coating 6 is prepared using plasma spraying technology. The spraying current is 120A-150A, the arc voltage is 25V-30V, and the spraying speed is 5mm / s-8mm / s. The surface of the stirring head, including the stirring shaft 1 and the stirring blades 2, is sandblasted with 80-120 mesh brown corundum abrasive particles at a pressure of 0.5MPa-0.8MPa. The stirring head is preheated before spraying the wear-resistant and anti-slag-caking coating 6 at a temperature of 300℃-400℃ for 1-2 hours. After spraying the wear-resistant and anti-slag-caking coating 6, it undergoes slow cooling at a rate of 50℃ / h-100℃ / h. A connecting flange 4 is fixedly installed at the top of the stirring shaft 1. The connecting flange 4 has 4-6 evenly distributed bolt holes 5 with a diameter of 16mm-20mm. The connecting flange 4 and the stirring shaft 1 are integrally cast structures. The thickness of the connecting flange 4 is 20mm-30mm, and the outer diameter of the connecting flange 4 is 50mm-80mm larger than the outer diameter of the stirring shaft 1.

[0026] Example 1

[0027] Preparation of the stirring head base: According to the chemical composition requirements of high chromium nickel heat-resistant steel, molten steel is smelted in an electric arc furnace, and then the stirring shaft 1, stirring blade 2 and connecting flange 4 blanks are made by casting process. The stirring blade 2 is spiral in shape with a spiral angle of 30°. Four bolt holes 5 with a diameter of 16mm are opened on the connecting flange 4. After that, the blanks are machined to ensure the dimensional accuracy of each component.

[0028] Surface sandblasting treatment: 80-mesh brown corundum abrasive particles are selected and sandblasted at a sandblasting pressure of 0.5MPa to remove surface oxide scale and oil stains from the surface of the stirring head, including the stirring shaft 1 and the stirring blades 2.

[0029] Preheating treatment: Place the sandblasted stirring head into a heating furnace and heat it to 300℃ at a rate of 100℃ / h, and keep it at that temperature for 1 hour.

[0030] Plasma spray coating: Using plasma spray welding equipment, the spray welding current is set to 120A, the arc voltage to 25V, and the spray welding speed to 5mm / s. A wear-resistant and anti-slag coating 6WC-Co alloy is sprayed onto the working surface of the stirring blade 2. The thickness of the wear-resistant and anti-slag coating 6 is 0.5mm.

[0031] Slow cooling treatment: After the spray welding is completed, the stirring head is placed in the heat preservation furnace and cooled to room temperature at a cooling rate of 50℃ / h to obtain an anti-slag long-life molten iron ladle stirring head.

[0032] The stirring head was applied to the molten iron pretreatment operation of a steel plant. After 6 months of use, the amount of slag on the surface of the stirring head was small, and only the stirring blade 2 showed slight wear. It can still meet the stirring requirements normally. Its service life is 3 times longer than that of the ordinary stirring head previously used by the plant. Moreover, each maintenance can be completed within 30 minutes through the connecting flange 4 and bolt holes 5, saving more than 1 hour of maintenance time compared to ordinary stirring heads.

[0033] Example 2

[0034] Preparation of the stirring head base: The same high-chromium-nickel heat-resistant steel material and casting and machining process as in Example 1 are used. The helix angle of the stirring blade 2 is 45°, and 6 bolt holes 5 with a diameter of 20mm are opened on the connecting flange 4.

[0035] Surface sandblasting treatment: 120-mesh brown corundum abrasive particles are selected and sandblasted on the surface of the stirring head, including the stirring shaft 1 and the stirring blades 2, under a sandblasting pressure of 0.8MPa.

[0036] Preheating treatment: Place the sandblasted stirring head into a heating furnace and heat it to 400℃ at a heating rate of 150℃ / h, and keep it at that temperature for 2 hours.

[0037] Plasma spray coating: The spray welding current is set to 150A, the arc voltage to 30V, and the spray welding speed to 8mm / s. The wear-resistant and anti-slag coating 6WC-Co alloy is sprayed onto the working surface of the stirring blade 2. The thickness of the wear-resistant and anti-slag coating 6 is 1.0mm.

[0038] Slow cooling treatment: After the spray welding is completed, the stirring head is placed in the heat preservation furnace and cooled to room temperature at a cooling rate of 100℃ / h.

[0039] After being used in a steel plant for 8 months, the agitator showed no obvious slag buildup or severe wear on its surface. The wear-resistant and anti-slag coating 6 on the agitator blades 2 remained in good condition, and the agitation efficiency remained at a high level. Its service life was extended by 4 times compared to existing ordinary agitators. During maintenance, the disassembly and assembly time via the connecting flange 4 and bolt holes 5 was only 25 minutes, further improving production efficiency.

[0040] Furthermore, all contents not described in detail in this specification are existing technologies known to those skilled in the art, and all electrical components mentioned in this document are powered by external power supply lines.

[0041] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0042] Although embodiments of this application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A long-life, anti-slagging stirring head for molten iron ladles, comprising a stirring shaft (1) and stirring blades (2), characterized in that: The stirring blades (2) are evenly distributed in a spiral shape on the outside of the stirring shaft (1), and the spiral angle of the stirring blades (2) is 30°-45°; the surface of the stirring blades (2) is provided with a number of guide ribs (3) extending along its length direction, the distance between adjacent guide ribs (3) is 20mm-30mm, and the height of the guide ribs (3) is 5mm-8mm; the base material of the stirring shaft (1) and the stirring blades (2) is high chromium nickel heat-resistant steel; the working surface of the stirring blades (2) is provided with a layer of wear-resistant and anti-slagging coating (6), the thickness of the wear-resistant and anti-slagging coating (6) is 0.5mm-1.0mm, and the material of the wear-resistant and anti-slagging coating (6) is WC-Co alloy.

2. The anti-slagging, long-life molten iron ladle stirring head according to claim 1, characterized in that: The top end of the stirring shaft (1) is fixedly provided with a connecting flange (4), and the connecting flange (4) has 4-6 evenly distributed bolt holes (5), the diameter of which is 16mm-20mm.

3. The anti-slagging, long-life molten iron ladle stirring head according to claim 2, characterized in that: The connecting flange (4) and the stirring shaft (1) are integrally cast structures. The thickness of the connecting flange (4) is 20mm-30mm, and the outer diameter of the connecting flange (4) is 50mm-80mm larger than the outer diameter of the stirring shaft (1).

Images