RU2062304C1 - Cutting tool - Google Patents

Abstract

FIELD: metal surface hardening processes. SUBSTANCE: a cutting tool is made of steel, alloying by transition metals of YI-group, and has a cutting edge, formed by crossing of working surfaces of a blade and hardened by particles of refractory compounds of alloying elements. A maximum diameter of particles of refractory compounds is selected in such a way, that it is no more than a rounding radius of the cutting edge; a ratio of an interval between these particles to the maximum diameter of the particles consists (3-10). EFFECT: increased service life period of such tool. 2 cl, 2 dwg, 1 tbl

Description

 The present invention relates to the field of hardening surface treatment of metals, and more specifically relates to cutting tools and can be used in various sectors of the economy, in particular in the chemical, textile, pulp and paper industry, leather industry.

 Known cutting tool with a cutting edge hardened by particles of the coating material by denting them into the base material (application of Germany N3139871, CL B23P 17/00, 04/21/83).

In this cutting tool, 50 CrMo ₄ steel sprayed at a temperature of 1050 ^o C. was used as a coating material.

 The specified tool has insufficient hardness of the coating material when using the tool, for example for cutting chemical fibers, and therefore a relatively low resistance.

 Known cutting tool based on steel alloyed with transition metals of group VI of the periodic system of elements, the cutting edge of which is formed by the intersection of the working surfaces of the blade and hardened by particles of refractory compounds of alloying elements (USSR patent N1790625, class C23C 8/36, 01/23/93).

 In the specified tool, the hardened part of the cutting edge consists of two layers. The first layer is applied to the substrate using a glow discharge. The second layer is obtained by ion treatment of the first layer.

 In the specified tool, there is a sharp boundary between the base and the hardened part; during its formation, the cutting edge may become dull, which affects the quality of the tool.

 The basis of the invention was the task of creating a cutting tool, the cutting edge of which would be so designed that would significantly improve the quality of the tool.

 The problem is solved in that in a cutting tool based on steel alloyed with transition metals of group VI of the periodic system of elements, the cutting edge of which is formed by the intersection of the working surfaces of the blade and hardened by particles of refractory compounds of alloying elements, according to the invention, the maximum particle diameter of refractory compounds of alloying elements is made not exceeding the radius of rounding of the cutting edge, and the ratio of the distance between these specified particles to the maximum mu diameter of these particles is selected in the range of 10 March.

 The maximum diameter of the particles should not exceed the radius of rounding of the cutting edge, since otherwise there is insufficient adhesion of the particles emerging on the surface of the cutting edge to the base material (due to the small contact surface), which during operation leads to chipping of the particles and blunting of the cutting edge tool. The distance between these particles is determined by the fact that, on the one hand, a sufficient hardness of the cutting edge of the tool should be provided, and, on the other hand, the layer should not be brittle, so that during operation there is no quick chipping of particles and blunting of the tool.

 The thickness of the hardened layer on the working surfaces of the blade can be performed (5 50) ρ, where r is the radius of rounding of the cutting edge.

 With a smaller thickness of the hardened layer, it decreases significantly when sharpening the tool and then quickly wears out during operation, as a result of which the tool life is insignificant. With a greater thickness of the layer, chipping of the cutting edge occurs.

 The above ratios are shown on the basis of a new direction in mechanics of the physical mechanics of the environment with a structure developed by one of the authors of the proposed invention, academician V.E. Panin.

 The advantages of the invention are that the cutting tool has a hardened layer with the desired parameters (thickness, particle size, ratio of the distance between particles to the maximum diameter), which ensures high quality of the tool.

Further, the invention is illustrated by a description of specific examples of its implementation and the accompanying drawings, in which:
figure 1 depicts the proposed cutting tool (cross section);
figure 2 plot a in figure 1 on an enlarged scale.

 The proposed cutting tool contains a base 1 (figure 1) of steel alloyed with transition metals of group VI of the periodic system of elements, and a cutting edge 2 formed by the intersection of the working surfaces of the blade and hardened by particles 3 of refractory compounds of alloying elements. The maximum diameter D (figure 2) of the particles 3 of the refractory compounds of the alloying elements is made not exceeding the radius r (figure 1) of the rounding of the cutting edge 2.

 The ratio L / D of the distance L (FIG. 2) between these particles 3 to the maximum diameter D of these particles 3 is selected in the range that corresponds to 3 10, that is, L / D (3 10).

 The thickness t (Fig. 1) of the hardened layer 4 on the working surfaces of the blade is made (5 50) r.

 Below will be described a method of obtaining the proposed cutting tool.

This method consists in the fact that the proposed cutting tool is processed in a nitrogen-containing glow discharge plasma. The processing of the cutting tool in a nitrogen-containing glow discharge plasma is carried out for 15 150 minutes at a temperature of 450 600 ^o C.

 The following are specific examples of the proposed cutting tool.

 Example 1

A cutting tool for cutting chemical fiber with dimensions of 20x100x0.9 was made on the basis of 1 (Fig. 1) of steel 65X13 (steel contains 13% of metal of group VI of chromium). After mechanical and thermal processing of the cutting edge 2, the tool was processed in a nitrogen-containing glow discharge plasma for 20 min at a temperature of 480 ^{° C.} to create a hardened layer 4 of the cutting edge 2 with r 1 μm.

), имеющий микротвердость H₁₀₀ 10,1 ГПа.A cutting tool with t 5ρ was obtained,

) having a microhardness of H ₁₀₀ 10.1 GPa.

 Example 2

The cutting tool was made in the same way as in example 1, but for 90 minutes at a temperature of 500 ^o C.

, имеющий микротвердость Н₁₀₀ 11,0 ГПа.A cutting tool was obtained with t 20ρ,

having a microhardness of N ₁₀₀ 11.0 GPa.

 Example 3

The cutting tool was made in the same way as in example 1, but for 150 minutes at a temperature of 520 ^o C.

, имеющий микротвердость Н₁₀₀ 11,0 ГПа.A cutting tool with t 50ρ was obtained,

having a microhardness of N ₁₀₀ 11.0 GPa.

 The table below shows the characteristics of the hardened layer 4 (Fig. 1) of the cutting edge 2 of the proposed tool and the results of industrial tests obtained in the examples described above (20 tools were prepared and tested for each mode, the table shows the average values). As a criterion of durability, the number of cuts was used when cutting Nitron fiber. The comparison was carried out with a tool manufactured by Lutz (Germany), whose passport service life is 40,000 cuts.

 From the above data it is seen that the proposed tool has a resistance 4-6 times higher than the resistance of known tools, that is, has a significantly better quality.

 The preferred embodiments of the present invention have been described above, in which those skilled in the art can make changes that do not go beyond the essence of the claims. TTT1 TTT2

Claims (2)

 1. A cutting tool based on steel alloyed with transition metals of group VI of the periodic system of elements, the cutting edge of which is formed by the intersection of the working surfaces of the blade and hardened by particles of refractory compounds of alloying elements, characterized in that the maximum particle diameter of refractory compounds of alloying elements is made not exceeding the radius of rounding of the cutting edges, and the ratio of the distance between these particles to the maximum diameter of these particles is selected in the range of 3-10.  2. The tool according to p. 1, characterized in that the thickness of the hardened layer on the working surfaces of the blade is made (5 ÷ 50) ρ, where ρ is the radius of rounding of the cutting edge.

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