Ceramic cast steel composite reamer tooth

Abstract

The invention discloses a ceramic cast steel composite reamer tooth and relates to the technical field of alloy cast steel matrix and random ceramic compositing, the reamer tooth is manufactured through a ceramic particle shaping process and a molten metal pouring process, and the ceramic particle shaping process comprises the steps of metallization pretreatment of ceramic particles, mixing of the ceramic particles, a binder and metal powder and the like; the molten metal pouring process comprises the steps of molten metal gravity pouring, high-temperature quenching and tempering heat treatment and the like. Compared with the prior art, the composite reamer tooth is formed by staggering the alloy cast steel base body and the random ceramic composite body, under the same working condition, the abrasion resistance of the reamer tooth for the dredger can be improved, the service life of the reamer tooth is prolonged by more than two times, the operation cost is reduced, and the working efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of alloy cast steel matrix and conformal ceramic composite, in particular to a ceramic cast steel composite reamer tooth. Background Art

[0002] Cutter suction dredger is a widely used engineering vessel in dredging construction, especially in rock dredging projects. The working principle is: the dredged medium (mud, sand, stone, etc.) is excavated and loosened by the rotary cutting of the auger, and mixed with water to form mud, and the filling operation is completed through the mud pump system and pipeline system. As an important component of the auger, the auger tooth is the only part of the auger to achieve cutting and excavation of the dredged medium. Its wear resistance directly affects the overall life of the auger. During dredging, the auger teeth complete the cutting and excavation of the dredged medium on the one hand, and realize the anti-wear protection of the auger body on the other hand. Therefore, the wear of the auger teeth is the main form of auger failure, but wear is also an inevitable situation in the use of auger teeth. During construction, auger teeth often break and excessive wear occurs, which reduces the effective excavation efficiency of the auger to a certain extent. At the same time, due to factors such as the large amount of auger teeth replacement, high work intensity, and long time required, the production capacity of the auger suction dredger is affected to a certain extent.

[0003] In production practice, reamer teeth are mainly made of medium carbon alloy steel precision casting, and the tooth hardness reaches 45~52HRC after heat treatment. In order to improve the wear resistance of reamer teeth, some companies adopt the method of surfacing anti-wear layer on the tooth surface, but this method is time-consuming and labor-intensive, and the surfacing layer is prone to cracks and peeling during use, which increases the number of repairs and replacements, increases the cost of use, and is not conducive to promotion and use. Some companies also use liquid-solid composite casting technology. This method sets high-chromium cast iron molten blocks on the tooth surface for composite casting. It has high requirements for working condition adaptability and does not meet the reality of the changing working conditions on the seabed. Especially when there are rocks in the construction area, its wear-resistant layer is fragile and easy to fall off. Some companies also use the method of inlaying carbide rods on the core of reamer teeth. The wear of the teeth starts from the tooth surface. After the matrix of the carbide wrapped around the tooth core is worn, the tooth core lacks the necessary support and is very easy to break and fall off, and cannot play a wear-resistant role.

[0004] Therefore, how to solve the above technical problems by improving the existing reamer tooth production method, enhancing wear resistance, and reducing the risk of reamer tooth breakage has become a technical challenge in this field. Summary of the invention

[0005] In response to the above technical problems, the present invention provides a ceramic cast-steel composite reamer tooth. The composite impeller blade surface is composed of high-chromium wear-resistant cast iron and metal-ceramic composite materials, which can completely solve the problems of poor wear resistance and short service life of existing reamer teeth.

[0006] The present invention solves the above problems by the following technical means: A ceramic cast steel composite reamer tooth, characterized in that it is made through a ceramic particle shaping process and a metal liquid pouring process, wherein: The ceramic particle shaping process comprises the following steps: 1) Surface roughening and metallization pretreatment of ceramic particles with a particle size of 1 mm to 3 mm; 2) The pretreated ceramic particles are uniformly mixed with a binder and a metal powder to obtain a particle mixture, wherein: the amount of the binder added is 2% to 10% of the mass of the ceramic particles, the particle size of the metal powder is 100 to 600 meshes, and the amount of the metal powder added is 2% to 8% of the mass of the particle mixture; 3) The particle mixture is uniformly loaded into a ceramic preform mold, and is pressed and heated. After demolding, a honeycomb or grid-shaped ceramic preform is obtained. The ceramic preform is a hollow cone, a hollow cuboid or a hollow truncated cone; The molten metal pouring process comprises the following steps: 4) Fixing the dried ceramic preform at the positioning point in the reamer tooth casting mold cavity and then closing the box; 5) Melt the cast steel material to form molten metal. Before casting, inspect the composition of the molten metal to ensure that the composition is C: 0.26~0.34%; Si: 0.4~1.2%; Mn: 0.4~1.2%; P: <0.035%; S: <0.035%; Cr: 1.2~1.8% ; Mo: 0.3~0.5%; Ni: 0.3~1.5%.

[0007] 6) Gravity pouring of molten metal at a pouring temperature of 1550°C to 1600°C is used, and the molten metal is cast and infiltrated into the composite body to obtain local ceramic particles to form alloy steel composite reamer teeth; 7) The formed alloy steel composite reamer teeth are subjected to high temperature quenching and tempering heat treatment, the quenching temperature is 890°C to 1080°C, and the tempering temperature is 320°C to 500°C.

[0008] Preferably, the metallization pretreatment step comprises: The surface of the ceramic particles is coated with a layer of nickel-based or titanium-based low-melting-point alloy material with a thickness of 0.05-0.2um by chemical plating or magnetron sputtering.

[0009] Preferably, the ceramic particles are one of aluminum oxide ceramic particles, silicon carbide ceramic particles, silicon nitride ceramic particles, and zirconium oxide ceramic particles, or a combination of any of them.

[0010] Preferably, the binder is one of sodium silicate, potassium silicate, silica sol, or a combination of any two of them.

[0011] Preferably, the metal powder is one of nickel powder, iron powder, aluminum powder and titanium powder, or a combination of any of them.

[0012] Preferably, the thickness of the honeycomb or grid-shaped ceramic preform is 5 mm to 20 mm.

[0013] Preferably, the cast steel material is ZG30CrNiMo material.

[0014] Preferably, a connecting hole is provided at the bottom of the reamer tooth, and the connecting hole is installed on a connecting boss of the base, the connecting boss is a polygonal frustum, a positioning plate is provided on the side of the connecting hole, two positioning teeth are provided at the end of the positioning plate, and a positioning platform is provided at the root of the connecting boss, and the positioning platform is used to contact the limit positioning plate.

[0015] Preferably, the reamer teeth are installed on the spiral cutter arm, the rake angle of the reamer teeth is 25° to 32°, the placement angle of the reamer teeth in the radial cross-sectional view is 30° to 40°, and the wrap angle of the reamer teeth in the axial cross-sectional view is designed to be 60° to 90°.

[0016] Preferably, the number of the spiral cutter arms is six or eight, and the spiral cutter arms are symmetrically installed between the cutter ring and the central sleeve, and six or eight cutter teeth are correspondingly arranged on the outer ring of the cutter ring.

[0017] The ceramic cast steel composite reamer tooth of the present invention has the following beneficial effects: 1) Through metallurgical composite technology, ceramic particles are embedded into the metal matrix, and the ceramic layer is composited with the metal matrix to give full play to the hardness advantage of ceramics while maintaining the toughness of metal materials, significantly improving the comprehensive performance of the material, thereby solving the problems of cracking, falling off, and matrix failure in existing technical solutions. In application, ceramic composite wear-resistant materials can effectively extend the service life of teeth by more than 2 times, reduce downtime caused by wear, improve work efficiency, reduce the frequency of tool replacement, and reduce operating costs.

[0018] 2) For the new reamer teeth, the tooth layout and spatial installation position were redesigned, the angular relationship between the rake angle, placement angle and wrap angle was improved, and the excavation efficiency was significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the implementation mode will be briefly introduced below. Obviously, the drawings described below are only some implementation modes of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 It is a schematic diagram of the structure of the ceramic preform of the present invention; Figure 2 It is a physical diagram of the present invention; Figure 3 It is a schematic diagram of the installation of the reamer teeth of the present invention; Figure 4 It is a schematic diagram of the cooperation between the reamer teeth and the base of the present invention; Figure 5 It is a schematic diagram of the layout of the reamer teeth of the present invention; Figure 6 It is a schematic diagram of the spiral blade arm structure of the present invention; Figure 7 It is a schematic diagram of the structure of the center sleeve of the present invention.

[0021] Among them, 1-cutting cutter teeth, 101-connecting hole, 102-positioning plate, 2-base, 201-connecting boss, 202-positioning platform, 3-spiral cutter arm, 4-cutting cutter ring, 5-center sleeve. DETAILED DESCRIPTION

[0022] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. The terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0023] The present invention will be described in detail below with reference to the accompanying drawings.

[0024] Ceramic composite materials, as a material with excellent hardness and wear resistance, have received extensive attention in recent years. In practical applications, ceramic materials have become an ideal choice to solve the problem of insufficient wear resistance of traditional materials due to their high hardness, low friction coefficient and excellent corrosion resistance. However, ceramic materials themselves are relatively brittle and easily break under impact or high stress environments. Therefore, in practical applications, the high hardness of ceramics and the toughness of other metal materials should be effectively combined, and the complete metallurgical coating of ceramics and base metals has become the focus of process technology research.

[0025] A ceramic cast steel composite reamer tooth is manufactured through a ceramic particle shaping process and a metal liquid pouring process, wherein the specific process is as follows: The ceramic particle shaping process includes the following steps: 1) Surface roughening and metallization pretreatment of ceramic particles with a particle size of 1 mm to 3 mm; 2) The pretreated ceramic particles are uniformly mixed with a binder and a metal powder to obtain a particle mixture, wherein: the amount of the binder added is 2% to 10% of the mass of the ceramic particles, the particle size of the metal powder is 100 to 600 meshes, and the amount of the metal powder added is 2% to 8% of the mass of the particle mixture; 3) The particle mixture is uniformly loaded into a ceramic preform mold, and pressed and heated. After demolding, a honeycomb or grid-shaped ceramic preform is obtained. The ceramic preform is a hollow cone, a hollow cuboid or a hollow truncated cone, such as Figure 1 As shown; The metal casting process includes the following steps: 4) Fixing the dried ceramic preform at the positioning point in the reamer tooth casting mold cavity and then closing the box; 5) Melt the cast steel material to form molten metal. Before casting, inspect the composition of the molten metal to ensure that the composition is C: 0.26~0.34%; Si: 0.4~1.2%; Mn: 0.4~1.2%; P: <0.035%; S: <0.035%; Cr: 1.2~1.8% ; Mo: 0.3~0.5%; Ni: 0.3~1.5%.

[0026] 6) Gravity pouring of molten metal at a pouring temperature of 1550°C to 1600°C is used, and the molten metal is cast and infiltrated into the composite body to obtain local ceramic particles to form alloy steel composite reamer teeth; Preferably, the pouring temperature is 1580°C.

[0027] 7) The formed alloy steel composite reamer teeth are subjected to high temperature quenching and tempering heat treatment, the quenching temperature is 890℃ to 1080℃, the tempering temperature is 320℃ to 500℃, and the finished product is as follows Figure 2 shown.

[0028] Preferably, the quenching temperature is 1000°C and the tempering temperature is 450°C.

[0029] In this embodiment, the metallization pretreatment step includes: coating the surface of the ceramic particles with a layer of nickel-based or titanium-based low melting point alloy material with a thickness of 0.05-0.2 um by chemical plating or magnetron sputtering. Preferably, the thickness is 0.15 um.

[0030] In this embodiment, the ceramic particles are one of alumina ceramic particles, silicon carbide ceramic particles, silicon nitride ceramic particles, zirconium oxide ceramic particles, or any combination thereof. Preferably, the alumina ceramic particles and the zirconium oxide ceramic particles are mixed in a ratio of 1:1.

[0031] In this embodiment, the binder is one of sodium silicate, potassium silicate, and silica sol, or any combination thereof. Preferably, the binder is a mixture of sodium silicate and potassium silicate in a ratio of 1:2.

[0032] In this embodiment, the metal powder is one of nickel powder, iron powder, aluminum powder, and titanium powder, or a combination of any of them.

[0033] In this embodiment, the thickness of the honeycomb or grid-shaped ceramic preform is 5 mm to 20 mm.

[0034] In this embodiment, the cast steel material is ZG30CrNiMo material.

[0035] In actual work, by embedding ceramic particles into the metal matrix and compounding the ceramic layer with the metal matrix, the hardness advantage of the ceramic is fully utilized, while maintaining the toughness of the metal material, significantly improving the comprehensive performance of the material, and thus solving the problems of cracking, falling off, matrix failure, etc. in the existing technical solutions. In application, ceramic composite wear-resistant materials can effectively extend the service life of teeth by more than 2 times, reduce downtime caused by wear, and improve work efficiency. This patented technology aims to optimize the composition and structure of ceramic composite materials, improve their wear resistance, impact resistance and bonding strength with the metal matrix, thereby providing a longer service life for tools such as reamer teeth, reducing the frequency of tool replacement, reducing operating costs, and improving work efficiency.

[0036] like Figures 3 to 7 As shown, a connecting hole 101 is provided at the bottom of the reamer tooth 1, and the connecting hole 101 is installed on a connecting boss 201 of the base 2. The connecting boss 201 is a polygonal frustum, and a positioning plate 102 is provided on the side of the connecting hole 101. Two positioning teeth are provided at the end of the positioning plate 102. A positioning platform 202 is provided at the root of the connecting boss 201, and the positioning platform 202 is used to contact the limit positioning plate 102.

[0037] In this embodiment, the reamer teeth 1 are mounted on the spiral cutter arms 3, the rake angle of the reamer teeth 1 is 25° to 32°, the placement angle of the reamer teeth 1 in the radial cross-sectional view is 30° to 40°, and the wrap angle of the reamer teeth 1 in the axial cross-sectional view is designed to be 60° to 90°. The number of spiral cutter arms 3 is six or eight, and the spiral cutter arms 3 are symmetrically mounted between the reamer ring 4 and the center sleeve 5, and six or eight reamer teeth 1 are correspondingly arranged on the outer ring of the reamer ring 4.

[0038] It should be noted that the new reamer teeth are made of new composite materials, and the tooth layout and spatial installation position need to be redesigned. Therefore, after a large number of experiments and simulations, the angular relationship between the rake angle, placement angle and wrap angle has been improved, which can significantly improve the excavation efficiency and structural strength.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A ceramic cast steel composite reamer tooth, characterized in that: It is made through ceramic particle shaping process and metal liquid pouring process, including: The ceramic particle shaping process comprises the following steps: 1) Surface roughening and metallization pretreatment of ceramic particles with a particle size of 1 mm to 3 mm; 2) The pretreated ceramic particles are uniformly mixed with a binder and a metal powder to obtain a particle mixture, wherein: the amount of the binder added is 2% to 10% of the mass of the ceramic particles, the particle size of the metal powder is 100 to 600 meshes, and the amount of the metal powder added is 2% to 8% of the mass of the particle mixture; 3) The particle mixture is uniformly loaded into a ceramic preform mold, and is pressed and heated. After demolding, a honeycomb or grid-shaped ceramic preform is obtained. The ceramic preform is a hollow cone, a hollow cuboid or a hollow truncated cone; The molten metal pouring process comprises the following steps: 4) Fixing the dried ceramic preform at the positioning point in the reamer tooth casting mold cavity and then closing the box; 5) Melt cast steel materials to form molten metal, and inspect the composition of the molten metal before casting; 6) Gravity pouring of molten metal at a pouring temperature of 1550°C to 1600°C is used, and the molten metal is cast and infiltrated into the composite body to obtain local ceramic particles to form alloy steel composite reamer teeth; 7) The formed alloy steel composite reamer teeth are subjected to high temperature quenching and tempering heat treatment, the quenching temperature is 890°C to 1080°C, and the tempering temperature is 320°C to 500°C.

2. The ceramic cast steel composite reamer tooth according to claim 1, characterized in that: The metallization pretreatment step comprises: The surface of the ceramic particles is coated with a layer of nickel-based or titanium-based low-melting-point alloy material with a thickness of 0.05-0.2um by chemical plating or magnetron sputtering.

3. The ceramic cast steel composite reamer tooth according to claim 1, characterized in that: The ceramic particles are one of aluminum oxide ceramic particles, silicon carbide ceramic particles, silicon nitride ceramic particles, and zirconium oxide ceramic particles, or a combination of any of them.

4. The ceramic cast steel composite reamer tooth according to claim 1, characterized in that: The binder is one of sodium silicate, potassium silicate and silica sol or a combination of any of them.

5. The ceramic cast steel composite reamer tooth according to claim 1, characterized in that: The metal powder is one of nickel powder, iron powder, aluminum powder and titanium powder, or a combination of any of them.

6. The ceramic cast steel composite reamer tooth according to claim 1, characterized in that: The thickness of the honeycomb or grid-shaped ceramic preform is 5 mm to 20 mm.

7. The ceramic cast steel composite reamer tooth according to claim 1, characterized in that: The cast steel material is ZG30CrNiMo material.

8. The ceramic cast steel composite reamer tooth according to claim 1, characterized in that: The bottom of the reamer tooth (1) is provided with a connection hole (101), the connection hole (101) is mounted on a connection boss (201) of the base (2), the connection boss (201) is a polygonal frustum, a positioning plate (102) is provided on the side of the connection hole (101), two positioning teeth are provided at the end of the positioning plate (102), and a positioning platform (202) is provided at the root of the connection boss (201), and the positioning platform (202) is used to contact the limit positioning plate (102).

9. The ceramic cast steel composite reamer tooth according to claim 8, characterized in that: The cutter tooth (1) is mounted on the spiral cutter arm (3); the rake angle of the cutter tooth (1) is 25° to 32°; the placement angle of the cutter tooth (1) in a radial cross-sectional view is 30° to 40°; and the wrap angle of the cutter tooth (1) in an axial cross-sectional view is designed to be 60° to 90°.

10. The ceramic cast steel composite reamer tooth according to claim 9, characterized in that: The number of the spiral cutter arms (3) is six or eight, and the spiral cutter arms (3) are symmetrically mounted between the cutter ring (4) and the central shaft sleeve (5), and six or eight cutter teeth (1) are correspondingly arranged on the outer ring of the cutter ring (4).

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