Preparation method of manganese steel-based steel bond hard alloy

Abstract

The invention discloses a preparation method of a manganese steel-based steel bond hard alloy. The preparation method comprises the following steps: step 1, burdening; step 2, grinding; step 3, preparing a blank; step 4, sintering; and 5, heat treatment. According to the method, titanium carbide and a metal binding phase are subjected to primary dry grinding and then wet grinding, and the rotating speed of wet grinding is reduced in the wet grinding process, so that mixing is mainly adopted in the wet grinding process, titanium carbide raw material particles can be excessively refined, it is guaranteed that titanium carbide is coarse particles, the wet grinding combination effect is better, and the service life of the titanium carbide is prolonged. And therefore, the number of gaps in a sintered alloy structure is small, the distribution uniformity of titanium carbide particles in a combined matrix is high, and the bending strength, the impact toughness and the hardness can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of hard alloy processing, in particular to a method for preparing manganese steel-based steel-bonded hard alloy. Background Art

[0002] Steel-bonded cemented carbide is a hard alloy made of refractory metal hard compounds as hard phase and steel as bonding phase. Steel-bonded cemented carbide has the hardness and wear resistance of carbides and the good mechanical properties of steel. It is mainly used as wear-resistant parts and machine components. Its organizational characteristics are that fine hard phases are evenly dispersed in the steel matrix;

[0003] The chemical formula of titanium carbide is TiC, and the molecular weight is 59.89. It is a gray metallic face-centered cubic lattice solid. The melting point is 3140±90℃, the boiling point is 4820℃, and the relative density is 4.93. The hardness is greater than 9. It is insoluble in water, but soluble in nitric acid and aqua regia. It is stable to air below 800℃, corroded by air above 2000℃, and can react with pure O2 at 1150C. Preparation method: A mixture of titanium powder obtained by reducing TiO2 with hydrogen and carbon is reacted at high temperature, or TiO2 is mixed with carbon powder and pressed into blocks, and then heated to 2300-2700℃ in an electric furnace and carbonized in an atmosphere of H2 or CO. Uses: To make cemented carbide, and also used as electrodes and abrasives for arc lamps;

[0004] In the preparation process of existing steel-bonded cemented carbide, titanium carbide as a hard material needs to be dry-ground first and then wet-ground during the process of mixing with the bonding phase metal matrix. However, during the dry and wet grinding processes, the titanium carbide particles are easily too fine. When the titanium carbide particles are excessively ground and the particles are finer, the brittleness of the finished product is easily increased, which will affect its performance and service life during use. Therefore, we propose a preparation method for manganese steel-based steel-bonded cemented carbide. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing manganese steel-based steel-bonded hard alloy, which solves the problems raised in the background technology.

[0006] To achieve the above object, the present invention provides the following technical solution: a method for preparing manganese steel-based steel-bonded hard alloy, comprising the following method steps:

[0007] Step 1: Ingredients: weigh titanium carbide and metal binder phase raw materials according to a certain mass percentage;

[0008] Step 2: Grinding, titanium carbide and metal binder phase raw materials are mixed and introduced into a rolling ball mill, and dry grinding is first performed for 3 hours, and then wet grinding is performed after the dry grinding is completed. During the wet grinding, wet grinding medium is added for lubrication, and the wet grinding time is 18-22 hours. After the wet grinding is completed, the material is discharged;

[0009] Step 3: Blank making: Dry the ground material, then introduce the mixed material into a press, add a molding agent, and press it through a press to obtain a blank.

[0010] Step 4: Sintering, introducing the obtained green body into a sintering furnace for sintering. During the sintering process, three pressure peaks will appear. When the first and second pressure peaks are reached, the gas pressure in the sintering furnace is reduced by adjusting the pressure in the sintering furnace. When the third pressure peak is reached, the pressure is adjusted again to increase the intracranial pressure again, thereby avoiding the volatilization of metal objects and improving the sintering quality. After sintering, an alloy green body is obtained;

[0011] Step 5: heat treatment, quenching the obtained alloy blank at 800-1200° C. and tempering at 100-500° C. in a vacuum environment, and then cooling to obtain steel-bonded cemented carbide.

[0012] As a preferred embodiment of the present invention, the titanium carbide raw material is titanium carbide powder obtained by configuring titanium powder and carbon powder in an atomic ratio of 1:1.

[0013] As a preferred embodiment of the present invention, the percentages of the metal binder phase raw materials are: carbon 1-2%, chromium 1.5-2.5%, molybdenum 0.6-2%, vanadium 0.5-2%, silicon 0.6-0.9, manganese 10-15%, nickel 0.5-2%, and the balance is iron.

[0014] As a preferred embodiment of the present invention, the pressure applied by the press in step three is 200MPa-300MPa.

[0015] As a preferred embodiment of the present invention, the molding agent in step three is a SBS molding agent.

[0016] As a preferred embodiment of the present invention, the sintering temperature condition in step 4 is 1350°C-1400°C.

[0017] As a preferred embodiment of the present invention, the wet grinding medium in step 2 is anhydrous ethanol.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The present invention performs preliminary dry grinding on titanium carbide and a metal bonding phase, and then performs wet grinding. During the wet grinding process, the rotation speed of the wet grinding is reduced, so that the wet grinding process is mainly mixed, so that the titanium carbide raw material particles can be over-refined, thereby ensuring that the titanium carbide is a coarser particle, and the wet grinding bonding effect is better, so that there are fewer voids in the alloy structure after sintering, and the titanium carbide particles are highly evenly distributed in the matrix after bonding, which is beneficial to improving the bending strength, impact toughness and hardness;

[0020] By changing the pressure in the sintering furnace during vacuum sintering of the substrate, the exhaust effect of harmful gases can be improved, the reduction effect of metal oxides can be improved, the volatilization of the body metal can be avoided, and the sintering quality can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0022] Figure 1 The present invention is a flow chart of a method for preparing manganese steel-based steel-bonded hard alloy. DETAILED DESCRIPTION

[0023] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0024] The present invention discloses a method for preparing a manganese steel-based steel-bonded hard alloy, comprising titanium carbide and a metal bonding phase raw material;

[0025] The titanium carbide raw material is titanium carbide powder obtained by configuring titanium powder and carbon powder in an atomic ratio of 1:1;

[0026] The percentages of the raw materials of the metal bonding phase are: carbon 1-2%, chromium 1.5-2.5%, molybdenum 0.6-2%, vanadium 0.5-2%, silicon 0.6-0.9, manganese 10-15%, nickel 0.5-2%, and the balance is iron.

[0027] Embodiment 1

[0028] A method for preparing manganese steel-based steel-bonded hard alloy is as follows:

[0029] Titanium carbide and metal binder phase raw materials are weighed according to a certain mass percentage, mixed and introduced into a rolling ball mill, firstly dry-milled for 3 hours, then wet-milled, anhydrous ethanol is added as a medium for lubrication during wet milling, the wet milling time is 18 hours, the material is discharged after wet milling, the ground material is dried, and then the mixed material is introduced into a press, and SBS molding agent is added to press to obtain a green body, the pressure applied by the press is 200MPa, The prepared green body is introduced into a sintering furnace for sintering at a sintering temperature of 1350°C. During the sintering process, three pressure peaks will appear. When the first and second pressure peaks are reached, the gas pressure in the sintering furnace is reduced by adjusting the pressure in the sintering furnace. When the third pressure peak is reached, the pressure is adjusted again to increase the intracranial pressure again to avoid volatilization of metal objects and improve the sintering quality. After sintering, an alloy green body is obtained, and the obtained alloy green body is quenched at 800°C and tempered at 100°C in a vacuum environment, and then cooled to obtain steel-bonded cemented carbide.

[0030] Embodiment 2

[0031] A method for preparing manganese steel-based steel-bonded hard alloy is as follows:

[0032] Titanium carbide and metal binder phase raw materials are weighed according to a certain mass percentage, mixed and introduced into a rolling ball mill, firstly dry-milled for 3 hours, then wet-milled, anhydrous ethanol is added as a medium for lubrication during wet milling, the wet milling time is 20 hours, the material is discharged after wet milling, the ground material is dried, and then the mixed material is introduced into a press, and SBS molding agent is added to press to obtain a green body, the pressure applied by the press is 200MPa, The prepared green body is introduced into a sintering furnace for sintering at a sintering temperature of 1350°C. During the sintering process, three pressure peaks will appear. When the first and second pressure peaks are reached, the gas pressure in the sintering furnace is reduced by adjusting the pressure in the sintering furnace. When the third pressure peak is reached, the pressure is adjusted again to increase the intracranial pressure again to avoid volatilization of metal objects and improve the sintering quality. After sintering, an alloy green body is obtained, and the obtained alloy green body is quenched at 800°C and tempered at 100°C in a vacuum environment, and then cooled to obtain steel-bonded cemented carbide.

[0033] Embodiment 3

[0034] A method for preparing manganese steel-based steel-bonded hard alloy is as follows:

[0035] Titanium carbide and metal binder phase raw materials are weighed according to a certain mass percentage, mixed and introduced into a rolling ball mill, firstly dry-milled for 3 hours, then wet-milled, anhydrous ethanol is added as a medium for lubrication during wet milling, the wet milling time is 21 hours, the material is discharged after wet milling, the ground material is dried, and then the mixed material is introduced into a press, and SBS molding agent is added to press to obtain a green body, the pressure applied by the press is 200MPa, The prepared green body is introduced into a sintering furnace for sintering at a sintering temperature of 1350°C. During the sintering process, three pressure peaks will appear. When the first and second pressure peaks are reached, the gas pressure in the sintering furnace is reduced by adjusting the pressure in the sintering furnace. When the third pressure peak is reached, the pressure is adjusted again to increase the intracranial pressure again to avoid volatilization of metal objects and improve the sintering quality. After sintering, an alloy green body is obtained, and the obtained alloy green body is quenched at 800°C and tempered at 100°C in a vacuum environment, and then cooled to obtain steel-bonded cemented carbide.

[0036] Embodiment 4

[0037] A method for preparing manganese steel-based steel-bonded hard alloy is as follows:

[0038] Titanium carbide and metal binder phase raw materials are weighed according to a certain mass percentage, mixed and introduced into a rolling ball mill, firstly dry-milled for 3 hours, then wet-milled, anhydrous ethanol is added as a medium for lubrication during wet milling, the wet milling time is 21 hours, the material is discharged after wet milling, the ground material is dried, and then the mixed material is introduced into a press, and SBS molding agent is added to press to obtain a green body, the pressure applied by the press is 250MPa, The prepared green body is introduced into a sintering furnace for sintering at a sintering temperature of 1350°C. During the sintering process, three pressure peaks will appear. When the first and second pressure peaks are reached, the gas pressure in the sintering furnace is reduced by adjusting the pressure in the sintering furnace. When the third pressure peak is reached, the pressure is adjusted again to increase the intracranial pressure again to avoid volatilization of metal objects and improve the sintering quality. After sintering, an alloy green body is obtained, and the obtained alloy green body is quenched at 800°C and tempered at 100°C in a vacuum environment, and then cooled to obtain steel-bonded cemented carbide.

[0039] Embodiment 5

[0040] A method for preparing manganese steel-based steel-bonded hard alloy is as follows:

[0041] Titanium carbide and metal binder phase raw materials are weighed according to a certain mass percentage, mixed and introduced into a rolling ball mill, firstly dry-milled for 3 hours, then wet-milled, anhydrous ethanol is added as a medium for lubrication during wet milling, the wet milling time is 21 hours, the material is discharged after wet milling, the ground material is dried, and then the mixed material is introduced into a press, and SBS molding agent is added to press to obtain a green body, the pressure applied by the press is 300MPa, The prepared green body is introduced into a sintering furnace for sintering at a sintering temperature of 1350°C. During the sintering process, three pressure peaks will appear. When the first and second pressure peaks are reached, the gas pressure in the sintering furnace is reduced by adjusting the pressure in the sintering furnace. When the third pressure peak is reached, the pressure is adjusted again to increase the intracranial pressure again to avoid volatilization of metal objects and improve the sintering quality. After sintering, an alloy green body is obtained, and the obtained alloy green body is quenched at 800°C and tempered at 100°C in a vacuum environment, and then cooled to obtain steel-bonded cemented carbide.

[0042] The steel-bonded hard alloy obtained in the above embodiment was tested, and the results are shown in the following table:

[0043] Flexural strength(MPa) Rockwell hardness (HRC) Embodiment 1 1350 55 Embodiment 2 1400 58 Embodiment 3 1475 62 Embodiment 4 1474 64 Embodiment 5 1480 65

[0044] In summary, the present invention performs preliminary dry grinding on titanium carbide and a metal binder phase, and then performs wet grinding. During the wet grinding process, the rotation speed of the wet grinding is reduced, so that the wet grinding process is mainly mixing, so that the titanium carbide raw material particles can be over-refined, thereby ensuring that the titanium carbide is a coarser particle, and the wet grinding bonding effect is better, so that there are fewer voids in the alloy structure after sintering, and the titanium carbide particles are highly evenly distributed in the matrix after bonding, which is beneficial to improving the bending strength, impact toughness and hardness;

[0045] By changing the pressure in the sintering furnace during vacuum sintering of the substrate, the exhaust effect of harmful gases can be improved, the reduction effect of metal oxides can be improved, the volatilization of the body metal can be avoided, and the sintering quality can be improved.

[0046] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention.

[0047] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for preparing a manganese steel-based steel-bonded hard alloy, characterized in that: The method comprises the following steps: Step 1: Ingredients: weigh titanium carbide and metal binder phase raw materials according to a certain mass percentage; Step 2: Grinding, titanium carbide and metal binder phase raw materials are mixed and introduced into a rolling ball mill, and dry grinding is first performed for 3 hours, and then wet grinding is performed after the dry grinding is completed. During the wet grinding, wet grinding medium is added for lubrication, and the wet grinding time is 18-22 hours. After the wet grinding is completed, the material is discharged; Step 3: Blank making: Dry the ground material, then introduce the mixed material into a press, add a molding agent, and press it through a press to obtain a blank. Step 4: Sintering, introducing the obtained green body into a sintering furnace for sintering. During the sintering process, three pressure peaks will appear. When the first and second pressure peaks are reached, the gas pressure in the sintering furnace is reduced by adjusting the pressure in the sintering furnace. When the third pressure peak is reached, the pressure is adjusted again to increase the intracranial pressure again, thereby avoiding the volatilization of metal objects and improving the sintering quality. After sintering, an alloy green body is obtained; Step 5: heat treatment, quenching the obtained alloy blank at 800-1200° C. and tempering at 100-500° C. in a vacuum environment, and then cooling to obtain steel-bonded cemented carbide.

2. The method for preparing a manganese steel-based steel-bonded hard alloy according to claim 1, characterized in that: The titanium carbide raw material is titanium carbide powder obtained by configuring titanium powder and carbon powder in an atomic ratio of 1:

1.

3. The method for preparing a manganese steel-based steel-bonded hard alloy according to claim 1, characterized in that: The percentages of the raw materials of the metal bonding phase are: carbon 1-2%, chromium 1.5-2.5%, molybdenum 0.6-2%, vanadium 0.5-2%, silicon 0.6-0.9, manganese 10-15%, nickel 0.5-2%, and the balance is iron.

4. The method for preparing a manganese steel-based steel-bonded hard alloy according to claim 1, characterized in that: The pressure applied by the press in step 3 is 200MPa-300MPa.

5. The method for preparing a manganese steel-based steel-bonded hard alloy according to claim 1, characterized in that: The molding agent in step 3 is SBS molding agent.

6. The method for preparing a manganese steel-based steel-bonded hard alloy according to claim 1, characterized in that: The sintering temperature condition in step 4 is 1350°C-1400°C.

7. The method for preparing a manganese steel-based steel-bonded hard alloy according to claim 1, characterized in that: The wet grinding medium in step 2 is anhydrous ethanol.

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