CN101412104A - Method for preparing primary column shaped horniness phase composite wear-resistant grinder dish - Google Patents

Abstract

The invention discloses a preparation method of a primary columnar hard phase composite wear-resistant grinding disc. The prepared wear-resistant grinding disc is composed of two parts: a high-hardness columnar alloy hard phase and a high-toughness matrix metal. The specific method is to The alloy powder core wire is woven into a skeleton similar to the shape of a millstone, and the melted high-temperature matrix metal molten steel is poured into the cavity of the millstone mold; quickly put the braided millstone-shaped skeleton into the casting mold filled with high-temperature matrix metal molten steel In the cavity, using the heat of the high-temperature matrix molten steel, the braided alloy powder core wire skeleton is cast infiltrated, sintered or melted, and a highly dispersed high-hardness columnar alloy hard phase is formed in situ; cooled at room temperature, the obtained The metal with high toughness and high strength is used as the matrix, and the original columnar hard phase composite wear-resistant grinding disc with metallurgical combination is contained inside. It has super wear resistance and excellent impact toughness, and its service life is close to or exceeds that of similar imported products.

Description

A kind of preparation method of primary columnar hard phase composite wear-resistant grinding disc

technical field

The invention relates to the preparation of grinding discs, in particular to a method for preparing a composite wear-resistant grinding disc with a primary columnar hard phase. Composed of two parts, it has the high strength and high toughness of the base metal, and has the high hardness and high wear resistance of the hard phase, and can withstand high pressure and strong wear at the same time.

Background technique

Grinding disc is a kind of grinding tool on the grinding machine. It is mainly used in vertical mills in electric power, mining, cement, chemical industry, coal and other departments, and is used for grinding coal, ore, cement raw/clinker, etc. The wear resistance and toughness of the grinding disc directly affect its service life. At present, the materials used to make grinding discs are mainly high-alloy steel and cast iron. Although high-alloy steel has good toughness, it has low hardness, so its wear resistance is poor, and expensive rare alloy elements are used, so the product cost It is also high; and the use of cast iron materials, although the wear resistance is guaranteed, but due to the disadvantage of poor toughness, brittle fractures often occur during use, resulting in the shutdown of production enterprises. Although some composite materials are also used to make mill discs, they have not yet achieved good results.

Contents of the invention

In view of the defects or deficiencies in the above-mentioned prior art, the object of the present invention is to provide a method for preparing a primary columnar hard phase composite wear-resistant grinding disc, the columnar hard phase composite wear-resistant grinding disc prepared by the method, through The core is in-situ compounded to form a highly wear-resistant hard phase, and the hard phase and the high-toughness matrix phase interface have achieved a metallurgical combination, which has high wear resistance and high toughness, which solves the current wear resistance and toughness problems in the industry Difficult technical difficulties to reconcile.

In order to realize above-mentioned task, the present invention takes following technical solution:

A method for preparing a primary columnar hard phase composite wear-resistant grinding disc, characterized in that the wear-resistant grinding disc prepared by the method is composed of two parts: a high-hardness columnar alloy hard phase and a high-toughness matrix metal, which are compounded by casting, specifically comprising: Follow these steps:

Step 1, weaving the alloy powder core wire into a skeleton approximately in the shape of a millstone, and fixing it as a whole by binding and welding. The skeleton in the shape of a millstone accounts for 50% to 80% of the total volume of the actual millstone;

Step 2, using resin sand to make a grinding disc mold according to the requirements of the casting process;

Step 3: Pour the smelted and melted high-temperature matrix metal molten steel into the cavity of the millstone mold; quickly put the compiled millstone-shaped skeleton into the casting cavity filled with the high-temperature matrix metal molten steel, and use the high-temperature matrix metal steel The heat of the molten alloy powder core wire is cast infiltrated, sintered or melted, and the alloy elements in the alloy powder core wire material undergo short-range diffusion under the heat of the high-temperature matrix metal molten steel, forming highly dispersed high Hardness columnar alloy hard phase;

Step 4, cooling at room temperature, after the molten metal is cooled and solidified, the generated high-hardness columnar alloy hard phase is integrated with the metallurgical transition of the base metal, the casting is taken out, and the sand is cleaned to obtain a high-toughness, high-strength metal as the base, Contains metallurgically bonded composite wear-resistant grinding discs.

The original columnar hard phase composite wear-resistant grinding disc prepared by the method of the present invention has the following advantages:

1. Since the alloy powder core wire is used and the alloy powder is filled inside, under the high temperature of the matrix metal liquid, the alloy powder in the alloy powder core wire material sinters, dissolves, diffuses, and undergoes a metallurgical reaction with the base metal liquid. The endothermic effect of the alloy powder reduces the local temperature, shortens the crystallization process, and hinders the further diffusion of alloy elements, so that the alloy elements are enriched in situ, the grains are significantly refined, and a large number of dispersed high-hardness hard particles are precipitated. After solidification, a macrocolumn/ribbon-shaped hard phase embedded in the matrix metal is formed, and a good metallurgical transition bond is formed with the matrix metal, and the interface is firmly bonded, which solves the problem of hard phase shedding and fragmentation The organic unity of wear resistance and toughness can effectively avoid fatigue wear, and the composite material has good tensile and compressive properties. The overall performance of the composite wear-resistant grinding disc prepared by the method of the invention is excellent, which is significantly better than that of the grinding discs (or composite grinding discs) prepared from alloy steel, cast iron and ceramic materials.

2. Alloy powder can be proportioned according to the requirements of the workpiece, the composition is adjustable, and the adaptability is wide.

3. Since the alloy powder core wire does not contain impurities such as binders, there will be no defects such as slag inclusions and pores, and the internal structure performance is excellent, which is obviously better than the general powder metallurgy method to prepare the structure of wear-resistant composite materials.

4. The composite molding process of the present invention has strong controllability, high yield, stable production quality, and is convenient for large-scale production.

5. The columnar hard phase is generated by the overall in-situ reaction, and the phase interface achieves metallurgical bonding. The material structure is dense and has no obvious defects, which avoids the cracking phenomenon that occurs during the grinding process and the shedding phenomenon during use like the combined grinding disc.

6. According to the use of industrial and mining, the proportion of columnar hard phase in the matrix can be adjusted, and because the alloy powder core wire has good flexibility, it is easy to mechanize into various shapes and evenly distributed wire skeletons;

7. According to different application requirements, the diameter and distribution form of columnar hard phase can be adjusted, and the diameter of alloy powder core wire can be adjusted from millimeter level to micron level, so as to obtain products with more uniform structure distribution and better wear resistance;

8. Its service life can be increased by 5-10 times than that of grinding discs (or composite grinding discs) made of high alloy steel, cast iron or ceramic materials.

Description of drawings

Fig. 1 is the structural representation of alloy powder core wire;

Fig. 2 is a schematic diagram of the preparation process of the columnar hard phase composite wear-resistant grinding disc;

Fig. 3 obtains the schematic diagram of wear-resistant composite grinding disc through casting;

Fig. 4 is a partially enlarged view of A in Fig. 3;

Fig. 5 is the metallographic structure diagram of the grinding disc wear-resistant composite material;

The present invention will be described in further detail below in conjunction with the accompanying drawings and the embodiments given by the inventor.

Detailed ways

Referring to the accompanying drawings, according to the technical scheme of the present invention, an alloy powder core wire 3 with a certain diameter and an alloy powder ratio is prepared, and the alloy core wire 3 with a certain size and a certain proportion is woven into a skeleton 4 approximately in the shape of a millstone, and through binding Or the method of welding is fixed the millstone shape skeleton 4.

Adopt resin sand to make grinding disc mold 5 according to casting process requirements;

Pour molten steel of matrix metal 6 melted at a high temperature of 1600°C into the cavity of the millstone mold 5, and then quickly insert the millstone-shaped skeleton 4 into the cavity of the millstone mold 5, under the heat of the high-temperature matrix metal molten steel , the alloy powder core wire material 3 undergoes melting, sintering, infiltration or even dissolution, and a large amount of alloy elements in the alloy powder core wire material 3 produce a metallurgical compound reaction with the high-temperature matrix metal molten steel, and the alloy powder metal elements are carried out in the matrix metal molten steel Short-range diffusion, in-situ generation of high-hardness columnar hard phases with uniform distribution and metallurgical bonding with high-temperature matrix metals8;

Cooling at room temperature, after the molten metal is cooled and solidified, the formed high-hardness columnar alloy hard phase 8 and the base metal 6 are metallurgically transitionally combined and integrated, the casting is taken out, and the sand is cleaned to obtain a high-toughness and high-strength metal as the base. Composite wear-resistant grinding disc with metallurgically bonded primary columnar hard phase.

The diameter of the alloy powder core wire 3 ranges from Φ2mm to 10mm, and the wall thickness of the low carbon steel pipe skin 2 wrapping the alloy powder 1 is 0.1mm to 1mm; the particle size of the alloy powder 1 contained in the core of the alloy powder core wire 3 is 50 mesh to 300 mesh (Fig. 1), the alloy powder core wire 3 can also be made into a pressed strip for use.

The alloy powder at the core of the alloy powder core wire 3 is composed of high-carbon ferrochrome powder, and alloy powders such as ferromolybdenum powder, ferrotungsten powder, ferrosilicon powder, and ferromanganese powder can be added as needed.

The above-mentioned alloy powder may also be composed of one or more of tungsten carbide, silicon carbide, titanium carbide, aluminum oxide, silicon nitride, and titanium nitride powder.

The above-mentioned base metal is one of known cast steel or cast iron such as high manganese steel, low carbon steel, alloy steel, gray cast iron, and nodular cast iron.

The following are examples given by the inventors, but the present invention is not limited to the following examples.

Example 1: Preparation of a strip-shaped composite wear-resistant roll with high chromium alloy as the hard phase and A3 steel as the matrix

1. Wrap the alloy powder 1 in the low-carbon steel pipe skin 2 to form the alloy powder core wire 3; select the alloy powder core wire 3 with a cross-sectional size of Φ3mm, the alloy powder is high-carbon ferrochromium powder, and the particle size is 100 mesh to 150 mesh head;

2. Weave the alloy core wire into a skeleton 4 approximately in the shape of a millstone, and fix the skeleton by binding or welding;

3. Use resin sand to make the grinding disc mold 5 according to the requirements of the casting process;

4. A3 steel is selected as the base metal 6, and after being smelted and melted in an intermediate frequency furnace, it is released at 1600°C, and the molten steel is poured from the runner 7 into the cavity of the millstone mold 5 (Fig. 2);

5. Insert the disc-shaped skeleton 4 into the cavity of the disc casting mold 5 as a whole. Under the thermal action of the high-temperature matrix metal molten steel, the alloy powder core wire 3 is melted, sintered, infiltrated or even dissolved, and the alloy powder core wire 3, a large number of alloying elements in the metallurgical compound reaction with the high-temperature base metal molten steel, the metal elements of the alloy powder diffuse in the base metal molten steel in a short distance, and the high-hardness columnar hard steel with uniform distribution and metallurgical combination with the high-temperature base metal is formed in situ. Phase 8;

Then cool at room temperature, after the molten metal is cooled and solidified, the casting is taken out, and the sand is cleaned, and the high-chromium alloy is made into a composite wear-resistant grinding disc (as shown in Figure 3, Fig. The detailed structural features of A in 3 are shown in Fig. 4).

Of course, according to actual needs, the alloy powder can also be a mixture of high-carbon ferrochromium powder, ferromolybdenum powder, ferrotungsten powder, ferrosilicon powder, and ferromanganese powder.

According to different requirements, the alloy powder can also choose one or more mixtures of silicon carbide, titanium carbide, aluminum oxide, silicon nitride or titanium nitride powder.

In the above embodiments, according to different requirements, the base metal 3 can also be gray cast iron or nodular cast iron, both of which can be made into qualified composite wear-resistant grinding discs.

The metallographic structure diagram of the grinding disc wear-resistant composite material prepared by the present invention is shown in Figure 5. It has the high strength and high toughness of the matrix metal, and has the high hardness and high wear resistance of the hard phase, and can withstand high pressure and strong pressure at the same time. Wear and tear, its service life is close to or exceeds that of similar imported products, and the price is only 1/3-1/2 of imported products. It is cost-effective and has a longer service life than grinding discs (or composite grinding discs) made of high alloy steel, cast iron or ceramic materials. 5-10 times. It can bring significant economic benefits to the user unit.

Claims (7)

1. A method for preparing a primary columnar hard phase composite wear-resistant grinding disc, characterized in that the wear-resistant grinding disc prepared by the method is composed of a high-hardness columnar alloy hard phase and a high-toughness matrix metal through casting and compounding, Specifically include the following steps: Step 1, weaving the alloy powder core wire into a skeleton approximately in the shape of a millstone, and fixing it as a whole by binding and welding. The skeleton in the shape of a millstone accounts for 50% to 80% of the total volume of the actual millstone; Step 2, using resin sand to make a grinding disc mold according to the requirements of the casting process; Step 3: Pour the smelted and melted high-temperature matrix metal molten steel into the cavity of the millstone mold; quickly put the compiled millstone-shaped skeleton into the casting cavity filled with the high-temperature matrix metal molten steel, and use the high-temperature matrix metal steel The heat of the molten alloy powder core wire is cast infiltrated, sintered or melted, and the alloy elements in the alloy powder core wire material undergo short-range diffusion under the heat of the high-temperature matrix metal molten steel, forming highly dispersed high Hardness columnar alloy hard phase; Step 4, cooling at room temperature, after the molten metal is cooled and solidified, the generated high-hardness columnar alloy hard phase is integrated with the metallurgical transition of the base metal, the casting is taken out, and the sand is cleaned to obtain a high-toughness, high-strength metal as the base, Contains metallurgically bonded composite wear-resistant grinding discs. 2. The method according to claim 1, characterized in that the diameter of the alloy powder core wire material ranges from Φ2mm to 10mm, the wall thickness of the low-carbon steel pipe wrapping the alloy powder is 0.1mm to 1mm, and the alloy powder core wire The core of the material is filled with alloy powder, and the particle size is 50 mesh to 300 mesh. 3. The method according to claim 2, wherein the alloy powder is one or more mixtures of tungsten carbide, silicon carbide, titanium carbide, aluminum oxide, silicon nitride or titanium nitride powder. 4. The method according to claim 2, wherein the alloy powder is high-carbon ferrochrome powder, or high-carbon ferrochrome powder and ferromolybdenum powder, ferrotungsten powder, ferrosilicon powder, ferromanganese powder mixture. 5. The method of claim 1 wherein said base metal is cast steel or cast iron. 6. The method according to claim 5, wherein said cast steel is high manganese steel, low carbon steel or alloy steel. 7. The method of claim 5, wherein the cast iron is gray cast iron or nodular cast iron.

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