Method for improving hardness of welding joint of saw blade tooth back material and hard alloy band saw blade

Abstract

The invention provides a method for improving the hardness of a saw blade tooth back material welding joint and a hard alloy band saw blade. The method comprises the steps that a tooth material made of a hard alloy material is connected to a back material made of a high-speed steel material through welding, electric resistance welding is adopted for welding of the tooth material and the back material, the welding voltage ranges from 200 V to 220 V, the welding time ranges from 35 ms to 45 ms, and the welding pressure ranges from 1 kg to 1.6 kg; through the electric resistance welding mode and the setting of the welding voltage, the welding time and the welding pressure, the hardness of the welding joint of the hard alloy band saw blade tooth back material is greatly improved, and the hard alloy band saw blade with excellent performance is prepared.

Description

Technical Field

[0001] The invention relates to the technical field of saw blade manufacturing methods, and in particular to a method for improving the hardness of a welding joint of a saw blade tooth back material and a cemented carbide band saw blade. Background Art

[0002] Carbide band saw blades are important tools for sawing hard materials such as steel or non-ferrous metals. Carbide band saw blades are obtained by welding two heterogeneous materials, tooth material and back material. At present, the granular tooth material is usually welded to the back material that has been milled, quenched and tempered. This process can save a lot of materials. However, due to the huge differences in physical properties such as melting point, linear expansion coefficient, thermal conductivity, specific heat, etc. between the tooth material and the back material of the carbide band saw blade, the internal stress of the welded joint after back-tooth material welding is large, cracks are easy to form, brittleness is easy, the bending strength is low, and the quality of the welded joint is poor. Summary of the invention

[0003] In view of this, an object of the present invention is to provide a method for improving the hardness of a welding joint of a saw blade tooth back material and a cemented carbide band saw blade to solve the above-mentioned problem.

[0004] The present invention adopts the following scheme:

[0005] The present application provides a method for improving the hardness of the welding joint of the back material of a saw blade tooth, comprising connecting a tooth material of cemented carbide to a back material of high-speed steel by welding, and welding the tooth material and the back material by resistance welding, with a welding voltage of 200V-220V, a welding time of 35ms-45ms, and a welding pressure of 1kg-1.6kg.

[0006] Furthermore, the welding voltage is 208V, the welding time is 37ms, and the welding pressure is 1.2kg-1.4kg.

[0007] Furthermore, the welding pressure is 1.2 kg.

[0008] Furthermore, the back material is made of X32 steel, and the tooth material is made of AM70 cemented carbide particles.

[0009] Furthermore, the backing material is subjected to forming processing and heat treatment, wherein the heat treatment includes keeping the backing material at 1200° C. for 3 minutes, oil cooling to room temperature, and then performing three tempering treatments at 560° C. for 10 minutes.

[0010] Furthermore, the welded cemented carbide band saw blade is ground.

[0011] The present invention also provides a carbide band saw blade, which uses the method for improving the hardness of the welding joint of the saw blade tooth back material to weld the tooth material and the back material.

[0012] By adopting the above technical solution, the present invention can achieve the following technical effects:

[0013] By means of resistance welding and the setting of welding voltage, welding time and welding pressure, the hardness of the welding joint of the back material of the carbide band saw blade tooth is greatly improved, and a carbide band saw blade with excellent performance is produced. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 It is a schematic diagram of the structure of a carbide band saw blade;

[0016] Figure 2 is a scanning electron microscope (SEM) image of the welded joint of the back material of the carbide band saw blade teeth of each embodiment;

[0017] Figure 3 is a Vickers hardness diagram of the welded joint of the back material of the carbide band saw blade teeth of each embodiment;

[0018] Icon: tooth material 1, back material 2. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0020] Example

[0021] Combination Figures 1 to 3As shown, this embodiment provides a method for improving the hardness of a saw blade tooth back material welding joint, comprising connecting a carbide tooth material 1 to a high-speed steel back material 2 by welding, and welding the tooth material 1 and the back material 2 by resistance welding, and the welding voltage is 200V-220V, the welding time is 35ms-45ms, and the welding pressure is 1kg-1.6kg. The method for improving the hardness of a saw blade tooth back material welding joint is used to weld the tooth material 1 and the back material 2.

[0022] The following describes several specific examples of forming cemented carbide band saw blades, and compares and analyzes the hardness test of welded joints.

[0023] Specifically, the back material 2 is made of X32 steel, and the tooth material 1 is made of AM70 cemented carbide particles. The hardness test of the welded joint is measured using a micro Vickers hardness tester. The two sides of the test sample are respectively ground and polished with 120#, 200#, 400#, 800#, 1000#, 2000#, and 3000# sandpaper, and the polished sample is electrolytically polished using an electrolytic polishing machine (the polishing liquid is a mixture of 90ml alcohol and 10ml perchloric acid). The polishing voltage is 30V, the polishing time is 30s, and the polishing is completed by rinsing and drying with alcohol. The experimental load is 500g, and the holding time is 10s. Each sample is measured at 10 different positions, the maximum and minimum values ​​are discarded, and the arithmetic mean of the remaining data is taken as the measurement result.

[0024] Embodiment 1:

[0025] S1: forming and heat treating the backing material 2 (X32 steel);

[0026] Forming: laser cutting is used to form the backing material 2 (X32 steel) to meet the structural requirements of the resistance welding tooth shape;

[0027] Heat treatment: Backing material 2 (X32 steel) was kept at 1200℃ for 3 minutes, then oil-cooled to room temperature, and then tempered three times at 560℃ for 10 minutes;

[0028] S2: welding the tooth material 1 to the backing material 2 after the forming process and heat treatment in S1;

[0029] The tooth material 1 and the back material 2 are welded by a resistance welding machine, and the welding voltage is 208V, the welding time is 37ms, and the welding pressure is 1.1kg;

[0030] S3: Grind the welded carbide band saw blade to achieve the required accuracy.

[0031] Embodiment 2:

[0032] Steps S1 and S3 are the same as those in Example 1. In step S2, a resistance welding machine is used to weld the tooth material 1 and the back material 2, and the welding voltage is 208V, the welding time is 37ms, and the welding pressure is 1.2kg.

[0033] Embodiment 3:

[0034] Steps S1 and S3 are the same as those in Example 1. In step S2, a resistance welding machine is used to weld the tooth material 1 and the back material 2, and the welding voltage is 208V, the welding time is 37ms, and the welding pressure is 1.3kg.

[0035] Embodiment 4:

[0036] Steps S1 and S3 are the same as those in Example 1. In step S2, a resistance welding machine is used to weld the tooth material 1 and the back material 2, and the welding voltage is 208V, the welding time is 37ms, and the welding pressure is 1.4kg.

[0037] The scanning electron microscope (SEM) image of the welded joint of the carbide band saw blade tooth back material formed in Example 1 is as follows: Figure 2 A and Figure 3 As shown, the Vickers hardness of the welded joint is 506HV;

[0038] The scanning electron microscope (SEM) image of the welded joint of the carbide band saw blade tooth back material formed in Example 2 is as follows: Figure 2 Medium b and Figure 3 As shown, the Vickers hardness of the welded joint is 630HV;

[0039] The scanning electron microscope (SEM) image of the welded joint of the carbide band saw blade tooth back material formed in Example 3 is as follows: Figure 2 Medium c and Figure 3 As shown, the Vickers hardness of the welded joint is 553HV;

[0040] The scanning electron microscope (SEM) image of the welded joint of the carbide band saw blade tooth back material formed in Example 4 is as follows: Figure 2 Medium D and Figure 3 As shown, the Vickers hardness of the welded joint is 537HV;

[0041] From the above, it can be seen that the hardness of the welded joint of the carbide band saw blade tooth back material is greatly improved by resistance welding and the setting of welding voltage, welding time and welding pressure, and a carbide band saw blade with excellent performance is prepared.

[0042] The above are only preferred implementations of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention.

[0043] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0044] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0045] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

Claims

1. A method for improving the hardness of a saw blade tooth back material welding joint, comprising welding a carbide tooth material to a high-speed steel back material, characterized in that: Resistance welding is used to weld the tooth material and the back material, and the welding voltage is 200V-220V, the welding time is 35ms-45ms, and the welding pressure is 1kg-1.6kg.

2. The method for improving the hardness of the saw blade tooth back material welding joint according to claim 1, characterized in that: The welding voltage is 208V, the welding time is 37ms, and the welding pressure is 1.2kg-1.4kg.

3. The method for improving the hardness of the welding joint of the saw blade tooth back material according to claim 2, characterized in that: The welding pressure is 1.2 kg.

4. The method for improving the hardness of a saw blade tooth back material welding joint according to claim 1, characterized in that: The back material is made of X32 steel, and the tooth material is made of AM70 hard alloy particles.

5. The method for improving the hardness of the saw blade tooth back material welding joint according to claim 4, characterized in that: The backing material is subjected to forming processing and heat treatment, wherein the heat treatment includes keeping the backing material at 1200° C. for 3 minutes, oil cooling to room temperature, and then performing three tempering treatments at 560° C. for 10 minutes.

6. The method for improving the hardness of a welding joint of a saw blade tooth back material according to any one of claims 1 to 5, characterized in that: Grinding of welded carbide band saw blades.

7. A carbide band saw blade, characterized in that: The method for improving the hardness of the welding joint of the saw blade tooth back material as claimed in claim 6 is used to weld the tooth material and the back material.

Images