Method for brazing hard alloy and high-strength steel through combined brazing filler metal

Abstract

The invention belongs to the technical field of welding, and particularly relates to a method for brazing hard alloy and high-strength steel through combined brazing filler metal. The method for brazing the hard alloy and the high-strength steel through the combined brazing filler metal comprises the following steps that (1) film deposition is conducted, specifically, prepared slurry is poured into a groove mold, and a thin film is obtained after air drying; (2) pressing, wherein the aired thin films are stacked and pressed to obtain a main body brazing sheet and an outer frame brazing sheet; (3) combining: combining the main body brazing filler metal sheet and the outer frame brazing filler metal sheet together to obtain combined brazing filler metal; (4) brazing is conducted, specifically, the obtained combined brazing filler metal is used for welding of hard alloy and high-strength steel; the combined brazing filler metal is in a film shape and can be used for curved surface welding, due to the existence of the brazing flux in the outer frame assembly, the brazing time can be saved, errors caused by manual hanging can be reduced, the effects of preventing a welding seam from being oxidized and improving wetting can be achieved during brazing, and the strength of a hard alloy and high-strength steel brazing joint can be effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of welding, and in particular relates to a method for brazing hard alloy and high-strength steel with combined brazing filler metal. Background Art

[0002] Cemented carbide is a combination of superhard carbide and sticky metal, so its hardness and wear resistance are relatively high. In addition, it also has high strength and toughness. It is mainly used in tools, rollers and other parts. Cemented carbide has high hardness and brittleness, and it also has high cost, so it is difficult to process. In the process of welding and connecting cemented carbide and steel, the metallurgical combination of the two is achieved, which has high connection strength and is not affected by the size of the parts. Therefore, in the process of connecting cemented carbide and steel, the application space of welding technology is relatively wide, mainly because this method is efficient and high in quality. At present, the commonly used welding methods in the process of rigid connection between cemented carbide and steel are arc welding, diffusion welding, brazing, etc. Among them, the advantages of brazing technology in application are mainly: low heating temperature, low residual stress and low deformation, etc., and it will not be limited by the thickness of the workpiece. It has important application value in the welding of various special-shaped materials and precision and complex components. Summary of the invention

[0003] The purpose of the present invention is to provide a combined brazing material for cemented carbide brazing, so as to solve the problems of error in artificial brazing flux application, oxidation of brazing seams and need for further improvement of brazing seam strength during cemented carbide brazing.

[0004] The second object of the present invention is to provide a method for preparing the above-mentioned combined brazing filler metal for cemented carbide brazing.

[0005] The third object of the present invention is to provide application of the above-mentioned combined brazing material in brazing of cemented carbide and high-strength steel.

[0006] To achieve the above object, the technical solution of the combined brazing filler metal for cemented carbide brazing of the present invention is:

[0007] A. Film deposition: Pour the main body and the outer frame into the groove mold respectively, and dry them to obtain a film.

[0008] B. Pressing: Put the film into the pressing machine to obtain a pressed part, and stack the main pressed part and the outer frame pressed part respectively to obtain a main brazing sheet and an outer frame brazing sheet;.

[0009] C. Combination: Use the outer frame solder sheet to surround the periphery of the main solder sheet to obtain a combined solder.

[0010] D. Brazing: Use a clamp to fix the cemented carbide and high-strength steel, use a combined brazing material for welding, and the welding temperature is 30℃~80℃ above the liquidus line of the brazing material.

[0011] Furthermore, in step A, the main body includes 1-100 parts of metal powder, 0-10 parts of rare earth powder and 0.1-10 parts of colloid; the outer frame includes 1-100 parts of metal powder, 0-10 parts of rare earth powder, 0.1-10 parts of colloid and 0.1-80 parts of flux; the metal powder includes one or more of Cu-based powder, Fe-based powder, Co-based powder, Ni-based powder and Ag-based powder; the rare earth powder includes one or more of lanthanum, cerium, praseodymium, neodymium, promethium and samarium. The colloid includes but is not limited to one or more of PVB, glycerol, Tween, epoxy resin, polyamide resin and alcohol.

[0012] Furthermore, in the step B, the film obtained after drying is pressed by a press to obtain a desired pressed part thickness.

[0013] Furthermore, in the step C, the main body solder sheet and the outer frame solder sheet are connected together by rolling or gluing to achieve the combination of the solder sheets.

[0014] Furthermore, in the step D, the flux in the outer frame plays a role in preventing the weld from being oxidized and improving wetting, which can effectively improve the strength of the brazed joint between the cemented carbide and the high-strength steel.

[0015] Compared with the prior art, the combined brazing filler metal brazing method of the present invention has the following advantages:

[0016] The method for brazing cemented carbide and high-strength steel with a combined brazing filler metal described in the present invention comprises combining a main body part without brazing flux and an outer frame part containing brazing flux, and then assembling the obtained combined brazing filler metal and a surface to be welded for brazing. The brazing flux is added to the outer frame part to reduce the error caused by manual hanging of materials, save brazing time, prevent the weld from being oxidized and improve wetting during brazing, and can effectively improve the strength of the brazed joint between cemented carbide and high-strength steel. DETAILED DESCRIPTION

[0017] The present invention will be described in detail below. The exemplary embodiments and descriptions of the present invention are used to explain the present invention but are not intended to limit the present invention.

[0018] Embodiment 1

[0019] A method for brazing hard alloy and high-strength steel with combined brazing filler metal, the steps comprising:

[0020] A. Film deposition: Pour the main body and the outer frame into the groove mold respectively, and dry them to obtain a film.

[0021] B. Pressing: Put the film into a press to obtain a pressed part, and stack the main pressed part and the outer frame pressed part respectively to obtain a main brazing sheet and an outer frame brazing sheet;

[0022] C. Combination: Use the outer frame solder sheet to surround the periphery of the main solder sheet to obtain a combined solder.

[0023] D. Brazing: Use a clamp to fix the cemented carbide and high-strength steel, use a combined brazing material for welding, and the welding temperature is 30℃~80℃ above the liquidus line of the brazing material.

[0024] The main body is made of the following raw materials in parts by weight: 35 parts of Ag, 20 parts of Cu, 11 parts of Zn, 8 parts of Ni, 5 parts of Mn, 1 part of rare earth powder and 25 parts of colloid, the flux of the outer frame accounts for 80% by weight, and the brazing material accounts for 20% by weight.

[0025] Embodiment 2

[0026] The structure of the combined brazing filler metal for cemented carbide brazing in this embodiment is basically the same as that of the embodiment 1, except that:

[0027] The main body is made of the following raw materials in parts by mass: 40 parts of Ag, 16 parts of Cu, 8 parts of Zn, 6 parts of Ni, 4 parts of Mn, 1 part of rare earth powder and 25 parts of colloid, the mass of the brazing flux of the outer frame accounts for 75%, and the mass of the brazing material accounts for 25%.

[0028] Embodiment 2

[0029] The structure of the combined brazing filler metal for cemented carbide brazing in this embodiment is basically the same as that of the embodiment 1, except that:

[0030] The main body is made of the following raw materials by weight: 40 parts Ag, 16 parts Cu, 8 parts Zn, 6 parts Ni, 4 parts Mn, 1 part rare earth powder and 25 parts colloid. The outer frame part has a flux weight of 70% and a brazing material weight of 30%.

[0031] The technical solutions provided by the embodiments of the present invention are introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the embodiments of the present invention. The description of the above embodiments is only applicable to help understand the principles of the embodiments of the present invention. At the same time, for those skilled in the art, according to the embodiments of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for brazing cemented carbide and high-strength steel with combined brazing filler metal, characterized in that: The steps include: Film deposition: pour the main body and the outer frame into the groove mold respectively, and dry them to obtain a film; the shape of the mold includes but is not limited to square and round. Pressing: putting the film into a press to obtain a pressed part; the pressed part includes a main body pressed part and an outer frame pressed part; the main body pressed part and the outer frame pressed part are stacked respectively to obtain a main body solder sheet and an outer frame solder sheet; Combination: using the outer frame solder sheet to surround the periphery of the main solder sheet to obtain a combined solder; the combination method includes but is not limited to rolling and connecting the main solder sheet and the outer frame solder sheet together. Brazing: Use a clamp to fix the cemented carbide and high-strength steel, use a combined brazing material for welding, and the welding temperature is 30℃~80℃ on the liquidus line of the brazing material; the brazing includes but is not limited to induction brazing, furnace brazing, and flame welding.

2. The method for brazing cemented carbide and high-strength steel with combined brazing filler metal according to claim 1, characterized in that: The main body part comprises 1-100 parts of metal powder, 0-10 parts of rare earth powder and 0.1-10 parts of glue.

3. The method for brazing cemented carbide and high-strength steel with combined brazing filler metal according to claim 1, characterized in that: The outer frame part comprises 1-100 parts of metal powder, 0-10 parts of rare earth powder, 0.1-10 parts of colloid and 0.1-80 parts of flux.

4. The method according to claim 2 or 3, characterized in that: The metal powder includes one or more of Cu-based powder, Fe-based powder, Co-based powder, Ni-based powder and Ag-based powder; 5. The method according to claim 2 or 3, characterized in that: The rare earth powder includes one or more of lanthanum, cerium, praseodymium, neodymium, promethium and samarium.

6. The method according to claim 2 or 3, characterized in that: The colloid includes but is not limited to one or more of PVB, glycerol, Tween, epoxy resin, polyamide resin, and alcohol.