CN116445823A - High-hardness and high-toughness TiC-based high-manganese steel-bonded hard alloy and preparation method thereof - Google Patents

Abstract

The invention discloses a TiC-based high manganese steel bonded hard alloy with high hardness and high toughness and a preparation method thereof, comprising the following components in percentage by mass: 30-70% of titanium carbide, 35-45% of atomized iron powder, 10-15% of ferromanganese powder, 1-4% of reduced nickel powder and 1-4% of reduced molybdenum powder; wherein the titanium carbide comprises a first titanium carbide and a second titanium carbide, and the oxygen content of the first titanium carbide is 0.1-0.4wt%; the dosage of the first titanium carbide is 1/4-1 of the total amount of the titanium carbide. According to the invention, through the use of the first titanium carbide particles with low oxygen content and the atomized iron powder with fine grains, the oxygen content in the material is effectively reduced, the pressing performance is improved, and the hardness and toughness of the alloy are improved; the preparation process has the advantages of simple process flow and short process period, and can obviously reduce the energy consumption cost and improve the production efficiency.

Description

High-hardness and high-toughness TiC-based high-manganese steel-bonded hard alloy and preparation method thereof

technical field

The invention relates to the technical field of alloy preparation, in particular to a high-hardness and high-toughness TiC-based high-manganese steel-bonded hard alloy and a preparation method thereof.

Background technique

TiC-based high-manganese steel-bonded cemented carbide is a cemented carbide produced with TiC as the hard phase and high-manganese steel as the binding phase. Among them, the hardness of the hard phase carbide is high, and the high-manganese steel in the binding phase has Good mechanical properties, therefore, make TiC-based high-manganese steel-bonded cemented carbide exhibit excellent wear resistance, widely used in mining, metallurgy, building materials and other industries, and gradually stabilized into two grades of TM60 and TM52.

The existing TM52 brand has low hardness (61-62HRC) and poor toughness (4-6J/cm ² ). Under actual impact and abrasive wear conditions, its wear resistance is insufficient, which seriously affects the service life. Chinese patent CN 109898004 A discloses a high-strength and tough titanium carbide-high manganese steel bonded hard alloy and its preparation method and application. This technology uses titanium carbide powder as the hard phase, water-atomized iron-molybdenum pre-alloyed powder as the binder, and simultaneously adds nickel, manganese, carbon, inhibitors, etc., and obtains extremely fine mixed powder through ball milling under a protective medium. After secondary reduction to reduce the oxygen content, and then through molding + cold isostatic pressing, vacuum sintering, heat treatment and other processes, steel-bonded cemented carbide products can be obtained, which can improve the existing TM52 brand TiC-based high manganese steel to a certain extent Insufficient performance of cemented carbide.

However, in the process of realizing the technical solution of the invention in the embodiments of the present application, the inventors of the present application found that the above-mentioned technology has at least the following technical problems: using iron-molybdenum pre-alloyed powder as the binder, the cost is relatively high; the process is complicated and the process flow is too long , the duration of the wet grinding process alone reaches 60-184 hours, and the oxygen content of the material increases due to the wet grinding for too long, and two additional reduction processes are added to reduce the oxygen content, which further complicates the entire process. The long cycle and increased costs such as energy consumption do not conform to the development concept of energy conservation and environmental protection under the new situation, and are not suitable for industrial production.

Contents of the invention

The present invention solves the above-mentioned problems existing in the prior art by providing a high-hardness and high-toughness TiC-based high-manganese steel-bonded hard alloy and a preparation method thereof.

In order to solve the above technical problems, the present invention provides a high-hardness and high-toughness TiC-based high-manganese steel-bonded hard alloy, which includes the following components in mass percentage: 30-70% of titanium carbide, 35-45% of atomized iron powder %, ferromanganese powder 10-15%, reduced nickel powder 1-4%, reduced molybdenum powder 1-4%; wherein, the titanium carbide includes the first titanium carbide and the second titanium carbide, the first titanium carbide The oxygen content is 0.1-0.4wt%, and the oxygen content of the second titanium carbide is higher than that of the first titanium carbide; the amount of the first titanium carbide accounts for 1% of the total amount of the titanium carbide. /4～1.

In a preferred embodiment of the present invention, the oxygen content of the first titanium carbide is 0.15-0.35wt%.

In a preferred embodiment of the present invention, the oxygen content of the titanium carbide is 0.18-0.32wt%.

In a preferred embodiment of the present invention, the particle size of the first titanium carbide is 500-4000nm, and the particle size of the second titanium carbide, atomized iron powder, ferromanganese powder, reduced nickel powder and reduced molybdenum powder are 60-200 mesh.

In order to solve the above-mentioned technical problems, the invention provides a method for preparing TiC-based high-manganese steel-bonded hard alloy with high hardness and high toughness, comprising the following steps:

(1) Weighing and mixing: take the above-mentioned raw materials according to the formula and mix them evenly;

(2) Wet milling treatment: place the raw materials weighed in step (1) in a ball mill, and carry out wet milling treatment with absolute ethanol as the medium;

(3) Molding and vacuum sintering treatment: After drying the wet-grinded raw materials in step (2), adding molding agent and molding them into billets, and then placing them in a vacuum sintering furnace for vacuum sintering treatment to obtain the high hardness High toughness TiC based high manganese steel bonded carbide.

In a preferred embodiment of the present invention, in the step (2), the process conditions of the wet grinding treatment are: a liquid-solid ratio of 120-150 ml/kg, and a wet grinding time of 17-22 hours.

In a preferred embodiment of the present invention, in the step (3), the molding agent is nitrile rubber.

In a preferred embodiment of the present invention, in the step (3), the process conditions of the vacuum sintering treatment are: a vacuum degree of 1 to 10 Pa, and the sintering heating and cooling processes are all carried out in a vacuum furnace, including the following stages:

The first stage: at a constant heating rate of 5-10°C/min, the temperature is raised from room temperature to 350-450°C, and the constant temperature is maintained for 1-1.5h;

The second stage: at a constant heating rate of 5-8°C/min, continue to heat up to 1000-1100°C, and keep the constant temperature for 1-1.5h;

The third stage: continue to heat up to 1350-1450°C at a constant heating rate of 2-4°C/min, and keep the constant temperature for 2-3 hours;

Finally, let it cool down to room temperature with the furnace.

The beneficial effects of the present invention are: a TiC-based high-manganese steel-bonded hard alloy with high hardness and high toughness and its preparation method, the first titanium carbide particles sintered by vacuum with low oxygen content and atomized iron with fine grains The use of powder effectively reduces the oxygen content in the material and increases the pressing energy, which helps to improve the hardness and toughness of the alloy; the preparation process of the present invention has a simple process flow and a short process cycle, which can significantly reduce energy consumption costs and improve Productivity.

Detailed ways

The preferred embodiments of the present invention are described in detail below, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, so as to define the protection scope of the present invention more clearly.

Embodiments of the invention include:

The invention discloses a TiC-based high-manganese steel-bonded hard alloy with high hardness and high toughness, which comprises the following components in mass percentage:

30-70% titanium carbide, the titanium carbide includes the first titanium carbide and the second titanium carbide, wherein the oxygen content of the first titanium carbide is 0.1-0.4wt%, prepared by vacuum sintering, containing oxygen The amount is low and the particle size is small, 500-4000nm, which can effectively increase the number of hard spots per unit volume of the cemented carbide, thereby improving the hardness of the titanium carbide-based high-manganese steel-bonded cemented carbide; the second titanium carbide is non- Vacuum sintered titanium carbide, its oxygen content is higher than that of the first titanium carbide, usually 0.6-0.8wt%; the amount of the first titanium carbide accounts for 1/4 of the total amount of the titanium carbide ~1 (that is, the minimum amount of the first titanium carbide is 1/4 of the total amount of titanium carbide, and the maximum amount is all the first titanium carbide). The first titanium carbide can significantly improve the hardness and other properties of titanium carbide-based high-manganese steel-bonded hard alloys, but the cost is high, and an appropriate amount of second titanium carbide can be used to ensure the performance of titanium carbide-based high-manganese steel-bonded hard alloys. Lower raw material costs.

Atomized iron powder is 35-45%, and the particle size is 60-200 mesh. Compared with reduced iron powder, atomized iron powder has the advantages of fine grain, uniform composition, and good compaction performance, which helps to improve and maintain the toughness of titanium carbide-based high-manganese steel-bonded cemented carbide.

10-15% of ferromanganese powder with a particle size of 60-200 mesh, 1-4% of reduced nickel powder with a particle size of 60-200 mesh, and 1-4% of reduced molybdenum powder with a particle size of 60-200 mesh. Manganese can inhibit the precipitation of carbon from austenite in high manganese steel bonded carbide, expand the austenite phase region, thereby reducing the oxidation decarburization of the alloy surface; and the main function of nickel powder and molybdenum powder is to improve the hardness of TiC. The wettability of phase and binder phase, while adding molybdenum can also play a certain role in precipitation strengthening, improving the strength, toughness and hardness of steel-bonded cemented carbide.

The preparation method of the above-mentioned high-hardness and high-toughness TiC-based high-manganese steel-bonded hard alloy is as follows: weigh each material according to the formula amount and mix them evenly, and then use absolute ethanol as the medium in a ball mill at a liquid-solid ratio of 120-150ml/ kg under the condition of wet grinding for 17-22 hours, and finally add nitrile rubber to form a blank, place it in a vacuum sintering furnace with a vacuum degree of 1-10Pa for vacuum sintering treatment, and obtain the high-hardness and high-toughness TiC-based high-manganese steel structure Cemented carbide; specifically, the sintering heating and cooling process is carried out in a vacuum furnace, including the following stages:

The first stage: at a constant heating rate of 5-10°C/min, the temperature is raised from room temperature to 350-450°C, and the constant temperature is maintained for 1-1.5h;

The second stage: at a constant heating rate of 5-8°C/min, continue to heat up to 1000-1100°C, and keep the constant temperature for 1-1.5h;

The third stage: continue to heat up to 1350-1450°C at a constant heating rate of 2-4°C/min, and keep the constant temperature for 2-3 hours;

Finally, let it cool down to room temperature with the furnace.

Example 1

Calculated by mass percentage, weigh 15% first titanium carbide, 25% second titanium carbide, 40% atomized iron powder, 15% ferromanganese powder, 2% reduced nickel powder and 3% reduced molybdenum powder, wherein, The particle size of the first titanium carbide is 4000nm, and the oxygen content is 0.2%; the particle size of the second titanium carbide, atomized iron powder, ferromanganese powder, reduced nickel powder and reduced molybdenum powder is within the range of 80-100 mesh. Weigh 150kg of the total amount of the above-mentioned material components.

Mix the above weighed materials evenly and put them into a ball mill, then add 120kg of absolute ethanol for wet milling for 19 hours, so that the alloy powders are evenly mixed.

Dry the raw material powder after wet grinding and mixing, then add 1.0wt% nitrile rubber as a molding agent, press it by unidirectional pressing method, and obtain a blank after demoulding; place the obtained blank in a vacuum with a vacuum degree of 8Pa Sintering is carried out in the sintering furnace to realize the densification of the alloy. The specific sintering process is as follows: firstly, the temperature is raised from room temperature to 350°C at a constant heating rate of 8°C/min, and kept at a constant temperature for 1 hour; then at a constant heating rate of 6°C/min, Continue to raise the temperature to 1000°C and keep it at a constant temperature for 1h; finally, continue to raise the temperature to 1400°C at a constant temperature rise rate of 4°C/min and keep it at a constant temperature for 2h; Carbide.

Example 2

Calculated by mass percentage, weigh 20% first titanium carbide, 20% second titanium carbide, 43% atomized iron powder, 13% ferromanganese powder, 2% reduced nickel powder and 2% reduced molybdenum powder, wherein, The particle size of the first titanium carbide is 3000nm, and the oxygen content is 0.25%; the particle size of the second titanium carbide, atomized iron powder, ferromanganese powder, reduced nickel powder and reduced molybdenum powder is within the range of 100-150 mesh. Weigh 150kg of the total amount of the above-mentioned material components.

Mix the above weighed materials evenly and put them into a ball mill, then add 120kg of absolute ethanol for wet milling for 20 hours, so that the alloy powders are evenly mixed.

Dry the raw material powder after wet grinding and mixing, then add 1.0wt% nitrile rubber as a molding agent, press it by unidirectional pressing method, and obtain a blank after demoulding; place the obtained blank in a vacuum with a vacuum degree of 5Pa Sintering is carried out in the sintering furnace to realize the densification of the alloy. The specific sintering process is as follows: firstly, the temperature is raised from room temperature to 400°C at a constant heating rate of 10°C/min, and kept at a constant temperature for 1 hour; then at a constant heating rate of 5°C/min, Continue to raise the temperature to 1000°C and keep it at a constant temperature for 1.5h; finally, continue to raise the temperature to 1400°C at a constant heating rate of 3°C/min and keep it at a constant temperature for 2h; cool down to room temperature with the furnace to obtain the high hardness and high toughness TiC-based high manganese steel Tungsten carbide.

Example 3

Calculated by mass percentage, weigh 25% first titanium carbide, 20% second titanium carbide, 40% atomized iron powder, 12% ferromanganese powder, 1% reduced nickel powder and 2% reduced molybdenum powder, wherein, The particle size of the first titanium carbide is 2500nm, and the oxygen content is 0.3%; the particle size of the second titanium carbide, atomized iron powder, ferromanganese powder, reduced nickel powder and reduced molybdenum powder is within the range of 150-200 mesh. Weigh 150kg of the total amount of the above-mentioned material components.

Mix the above weighed materials evenly and put them into a ball mill, then add 120kg of absolute ethanol for wet milling for 21 hours, so that the alloy powders are evenly mixed.

Dry the raw material powder after wet grinding and mixing, then add 1.0wt% nitrile rubber as a molding agent, press it by unidirectional pressing method, and obtain a blank after demoulding; place the obtained blank in a vacuum with a vacuum degree of 5Pa Sintering is carried out in a sintering furnace to realize the densification of the alloy. The specific sintering process is as follows: firstly, the temperature is raised from room temperature to 400°C at a constant heating rate of 8°C/min, and kept at a constant temperature for 1 hour; then at a constant heating rate of 5°C/min, Continue to raise the temperature to 1000°C and keep it at a constant temperature for 1.5h; finally, continue to raise the temperature to 1450°C at a constant heating rate of 3°C/min and keep it at a constant temperature for 2h; cool down to room temperature with the furnace to obtain the high hardness and toughness TiC-based high manganese steel Tungsten carbide.

Comparative example 1

Compared with Example 1, all the titanium carbides use the second titanium carbide.

Comparative example 2

Compared with Example 1, the atomized iron powder is all replaced by reduced iron powder.

The TiC-based high-manganese steel-bonded hard alloys prepared in Examples 1-3 and Comparative Examples 1-3 were prepared into 10 × 10 × 55mm samples, and the hardness of the samples was detected by a 200HRS-150 automatic Rockwell hardness tester. The average value was taken as the final result after each sample was measured 5 times. The impact toughness is tested on the XJ-40A pendulum impact testing machine, using a 10mm×10mm×55mm unnotched standard sample. The test results are shown in Table 1 below.

Table 1

As can be seen from the above experimental data, compared with Comparative Example 1 and Comparative Example 2, the present invention improves the hardness and impact toughness of the prepared TiC-based high manganese steel-bonded hard alloy through the selection and design of raw materials and processes, In particular, the impact toughness has been significantly improved, effectively solving the defect of insufficient impact toughness of the existing steel-bonded hard alloys.

In addition, the inventive preparation process has a short process flow, does not introduce a large amount of impurity oxygen elements during the preparation process, has a short process cycle, low energy consumption, and greatly saves production costs.

The present invention realizes the dual optimization effect of high performance and low cost from the combination of raw material selection and process design, and the prepared TiC-based high-manganese steel-bonded hard alloy has excellent impact toughness, low cost, low energy consumption, and high production efficiency. Short cycle and many other advantages are conducive to large-scale industrial production.

The above is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process conversion made by using the content of the description of the present invention, or directly or indirectly used in other related technical fields, shall be The same reasoning is included in the patent protection scope of the present invention.

Claims (8)

1. A high-hardness and high-toughness TiC-based high-manganese steel-bonded hard alloy is characterized in that it comprises the following components in mass percentage: 30-70% of titanium carbide, 35-45% of atomized iron powder, ferromanganese powder 10-15%, reduced nickel powder 1-4%, reduced molybdenum powder 1-4%; wherein, the titanium carbide includes the first titanium carbide and the second titanium carbide, and the oxygen content of the first titanium carbide is 0.1-0.4 wt%, the oxygen content of the second titanium carbide is higher than the oxygen content of the first titanium carbide; the amount of the first titanium carbide accounts for 1/4-1 of the total amount of the titanium carbide . 2. The high-hardness and high-toughness TiC-based high-manganese steel-bonded cemented carbide according to claim 1, characterized in that the oxygen content of the first titanium carbide is 0.15-0.35 wt%. 3. The high-hardness and high-toughness TiC-based high-manganese steel-bonded cemented carbide according to claim 2, characterized in that the oxygen content of the titanium carbide is 0.18-0.32 wt%. 4. The high-hardness and high-toughness TiC-based high-manganese steel-bonded cemented carbide according to claim 1, characterized in that, the particle size of the first titanium carbide is 500-4000nm, and the second titanium carbide, atomized iron The particle size of manganese powder, ferromanganese powder, reduced nickel powder and reduced molybdenum powder is 60-200 mesh. 5. a kind of preparation method of high hardness high tenacity TiC base high manganese steel bonded hard alloy as claimed in claim 1, is characterized in that, comprises the steps: (1) Weighing and mixing: take the above-mentioned raw materials according to the formula and mix them evenly; (2) Wet milling treatment: place the raw materials weighed in step (1) in a ball mill, and carry out wet milling treatment with absolute ethanol as the medium; (3) Molding and vacuum sintering treatment: After drying the wet-grinded raw materials in step (2), adding molding agent and molding them into billets, and then placing them in a vacuum sintering furnace for vacuum sintering treatment to obtain the high hardness High toughness TiC based high manganese steel bonded carbide. 6. The preparation method of the high-hardness and high-toughness TiC-based high-manganese steel-bonded cemented carbide according to claim 5, characterized in that, in the step (2), the process condition of the wet grinding process is: liquid-solid The ratio is 120~150ml/kg, and the wet grinding time is 17~22h. 7. The preparation method of high-hardness and high-toughness TiC-based high-manganese steel-bonded cemented carbide according to claim 5, characterized in that, in the step (3), the forming agent is nitrile rubber. 8. The preparation method of the high-hardness and high-toughness TiC-based high-manganese steel-bonded cemented carbide according to claim 5, characterized in that, in the step (3), the process condition of the vacuum sintering treatment is: vacuum degree 1～10Pa, the sintering heating and cooling process is carried out in a vacuum furnace, including the following stages: The first stage: at a constant heating rate of 5-10°C/min, the temperature is raised from room temperature to 350-450°C, and the constant temperature is maintained for 1-1.5h; The second stage: at a constant heating rate of 5-8°C/min, continue to heat up to 1000-1100°C, and keep the constant temperature for 1-1.5h; The third stage: continue to heat up to 1350-1450°C at a constant heating rate of 2-4°C/min, and keep the constant temperature for 2-3 hours; Finally, let it cool down to room temperature with the furnace.