Processing method of hard alloy material

Abstract

The invention provides a treatment method of a hard alloy material, which comprises the following steps: cooling a hard alloy sample from 20 DEG C to-190 DEG C within 210-420 min; after cooling, carrying out heat preservation for 2 hours in a liquid nitrogen atmosphere of-190 DEG C; and after heat preservation, heating and tempering to 30 DEG C, and preserving heat for 1 hour. By means of the treatment method, the number of refined grains of the treated hard alloy material is increased, and the content of the grains with the grain size smaller than 0.5 micrometer is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of cemented carbide treatment, and particularly relates to a method for treating cemented carbide materials. Background Art

[0002] Cemented carbide is an alloy material made of refractory metal hard compounds and binding metals through powder metallurgy. During the batch processing of domestic brand cemented carbide materials, their toughness, durability, stability, etc. are affected, and there is still a certain gap in terms of lifespan, wear resistance, processing strength, etc. compared with European and American tools. The main reason is that the number of refined grains in the material after being made by powder metallurgy is relatively small. Summary of the Invention

[0003] In order to overcome the deficiencies of the prior art, the purpose of the present invention is to provide a method for treating cemented carbide materials, so that the number of refined grains in the treated cemented carbide materials increases, and the content of grains with a particle size less than 0.5 μm increases.

[0004] To solve the above problems, the technical solutions adopted by the present invention are as follows:

[0005] A method for treating cemented carbide materials includes the following steps:

[0006] Cool the cemented carbide sample from 20°C to -190°C within 210 - 420 min;

[0007] After cooling, keep it warm in a liquid nitrogen atmosphere at -190°C for 2 h;

[0008] After heat preservation, heat it up for tempering and keep it warm at 30°C for 1 h.

[0009] In some possible embodiments, during the cooling step, cool the cemented carbide sample within 210 min at a cooling rate of 1°C / min.

[0010] In some possible embodiments, during the cooling step, cool the cemented carbide sample within 420 min at a cooling rate of 0.5°C / min.

[0011] In some possible embodiments, the time for heat-up tempering is 700 min.

[0012] In some possible embodiments, the cemented carbide sample includes WC, Co, TiC, and TaC, the mass fraction of WC is 84%, the mass fraction of Co is 6%, and the combined mass fraction of TiC and TaC is 10%.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0014] In the present application, through the coordinated cooperation of the cooling parameters, the heat preservation parameters under the liquid nitrogen atmosphere, and the heating and tempering parameters, the number of refined grains of the treated cemented carbide material increases, and the content of grains with a particle size less than 0.5 μm increases.

[0015] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Description of the Drawings

[0016] Figure 1 It is a flowchart of a method for treating the grains of a cemented carbide material provided in an embodiment of the present application.

[0017] Figure 2 It is the SEM image of sample 1 provided for Example 1;

[0018] Figure 3 It is the SEM image of sample 2 provided for Example 2;

[0019] Figure 4 The SEM image of untreated sample 3;

[0020] Figure 5 It is the histogram of the grain size statistics of sample 1;

[0021] Figure 6 It is the histogram of the grain size statistics of sample 2;

[0022] Figure 7 It is the histogram of the grain size statistics of sample 3. Specific Embodiments

[0023] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0025] Some embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0026] An embodiment of the present application provides a method for refining the grains of a cemented carbide material, including the following steps.

[0027] Step S101: Cool the cemented carbide sample from 20°C to -190°C within 210 - 420 min. Exemplarily, liquid nitrogen can be used for cooling.

[0028] In some embodiments, in this cooling step, cool the cemented carbide sample within 210 min at a cooling rate of 1°C / min.

[0029] In some embodiments, in the cooling step, cool the cemented carbide sample within 420 min at a cooling rate of 0.5°C / min.

[0030] The combination of the above cooling time and cooling rate is conducive to further increasing the proportion of smaller grains.

[0031] In some embodiments, the cemented carbide sample includes WC (tungsten carbide), Co (cobalt), TiC (titanium carbide), and TaC (tantalum carbide). The mass fraction of WC is 84%, the mass fraction of Co is 6%, and the combined mass fraction of TiC and TaC is 10%.

[0032] Step S102: After cooling, keep it warm for 2 h in a liquid nitrogen atmosphere at -190°C.

[0033] Step S103: After keeping it warm, heat it up for tempering to 30°C and keep it warm for 1 h. Exemplarily, the heating-up and tempering operation can be carried out by heating with the furnace.

[0034] In some embodiments, the time for heating up and tempering is 700 min.

[0035] In this application, through the synergistic cooperation of the cooling parameters, the heat preservation parameters in the liquid nitrogen atmosphere, and the heating-up and tempering parameters, the number of refined grains of the treated cemented carbide material increases, and the content of grains with a particle size less than 0.5 μm increases.

[0036] Example 1

[0037] Cool the cemented carbide sample from room temperature 20°C to -190°C (using liquid nitrogen atmosphere for cooling) within 210 min at a cooling rate of 1°C / min. After cooling, keep it warm for 2 h in a liquid nitrogen atmosphere at -190°C. After keeping it warm, carry out heating-up and tempering, temper for 700 min to 30°C and keep it warm for 1 h to obtain Sample 1. The heating can be carried out by heating with the furnace. The cemented carbide sample includes WC, Co, TiC, and TaC. The mass fraction of WC is 84%, the mass fraction of Co is 6%, and the combined mass fraction of TiC and TaC is 10%.

[0038] Example 2

[0039] The cemented carbide sample is cooled from room temperature of 20 °C to -190 °C within 420 min (using a liquid nitrogen atmosphere for cooling), with a cooling rate of 0.5 °C / min. After cooling, it is held at -190 °C in a liquid nitrogen atmosphere for 2 h. After holding, tempering is carried out by heating up. It is heated to 30 °C and held for 1 h within 700 min to obtain Sample 2. The heating-up can be carried out in a furnace-following manner. The cemented carbide sample includes WC, Co, TiC, and TaC. The mass fraction of WC is 84%, the mass fraction of Co is 6%, and the combined mass fraction of TiC and TaC is 10%.

[0040] The processed Sample 1, Sample 2, and the unprocessed Sample 3 (with the same composition as Sample 1 and Sample 2) are embedded using epoxy resin as the embedding powder. A diamond grinding disc is used for grinding to obtain the best flatness on the working surface of the sample, then polished with 1-μm diamond, and finally etched with Murakami reagent (10 g of potassium ferricyanide, 10 g of sodium hydroxide or potassium hydroxide, and 100 ml of water) for 3 - 6 min. The etchant is rinsed off with pure water, and then blotted dry with absorbent paper to be ready for microscopic structure observation and grain photography. The grain size is evaluated according to the metallic average grain size (intercept method) in GB / T 6394-2017.

[0041] The grain conditions of Samples 1, 2, and 3 are as Figures 2 to 7 shown. Analyze Figures 5 to 7From the grain size distribution, it can be seen that in Sample 1, the number of grains with a size of 0.1 μm is 1 (0.2%), the number of grains with a size of 0.2 μm is 29 (4.4%), the number of grains with a size of 0.3 μm is 124 (18.8%), the number of grains with a size of 0.4 μm is 161 (24.5%), the number of grains with a size of 0.5 μm is 185 (28.1%), the number of grains with a size of 0.6 μm is 79 (12.0%), the number of grains with a size of 0.7 μm is 48 (7.3%), the number of grains with a size of 0.8 μm is 15 (2.3%), the number of grains with a size of 0.9 μm is 7 (1.1%), the number of grains with a size of 1 μm is 6 (0.9%), the number of grains with a size of 1.1 μm is 2 (0.3%), the number of grains with a size of 1.2 μm is 1 (0.2%), and the total number of fine grains is 658. In Sample 2, the number of grains with a size of 0.1 μm is 0, the number of grains with a size of 0.2 μm is 25 (4.0%), the number of grains with a size of 0.3 μm is 149 (24.0%), the number of grains with a size of 0.4 μm is 170 (27.3%), the number of grains with a size of 0.5 μm is 119 (19.1%), the number of grains with a size of 0.6 μm is 75 (12.1%), the number of grains with a size of 0.7 μm is 51 (8.2%), the number of grains with a size of 0.8 μm is 18 (2.9%), the number of grains with a size of 0.9 μm is 11 (1.8%), the number of grains with a size of 1 μm is 3 (0.5%), the number of grains with a size of 1.1 μm is 0, the number of grains with a size of 1.2 μm is 1 (0.2%), and the total number of fine grains is 622. In Sample 3, the number of grains with a size of 0.1 μm is 0, the number of grains with a size of 0.2 μm is 14 (2.4%), the number of grains with a size of 0.3 μm is 94 (16.3%), the number of grains with a size of 0.4 μm is 158 (27.3%), the number of grains with a size of 0.5 μm is 142 (24.6%), the number of grains with a size of 0.6 μm is 80 (13.8%), the number of grains with a size of 0.7 μm is 39 (6.7%), the number of grains with a size of 0.8 μm is 23 (4.0%), the number of grains with a size of 0.9 μm is 14 (2.4%), the number of grains with a size of 1 μm is 7 (1.2%), the number of grains with a size of 1.1 μm is 6 (1.0%), the number of grains with a size of 1.2 μm is 1 (0.2%), and the total number of fine grains is 578. Similarly, it can be obtained that the number of fine grains of the cemented carbide obtained by the method of this application increases, and the proportion of grains with a size less than 0.5 μm increases.

[0042] The above embodiments are only the preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantive changes and substitutions made by those skilled in the art on the basis of the present invention belong to the scope of protection required by the present invention.

Claims

1. A method for treating a cemented carbide material, characterized in that, It includes the following steps: Cool the cemented carbide sample from 20°C to -190°C within 210 - 420 minutes; After cooling, keep it insulated in the liquid nitrogen atmosphere at -190°C for 2 hours; After insulation, heat it up for tempering and keep it insulated at 30°C for 1 hour.

2. The processing method according to claim 1, characterized in that, In the cooling step, cool the cemented carbide sample at a cooling rate of 1°C / min within 210 minutes.

3. The processing method according to claim 1, characterized in that In the cooling step, cool the cemented carbide sample at a cooling rate of 0.5°C / min within 420 minutes.

4. The processing method according to claim 1, wherein The time for heat-up tempering is 700 minutes.

5. The processing method according to claim 1, characterized in that, The cemented carbide sample includes WC, Co, TiC and TaC, the mass fraction of WC is 84%, the mass fraction of Co is 6%, and the total mass fraction of TiC and TaC is 10%.

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