Brazing method for tungsten carbide die punching head and steel base

Abstract

The invention relates to a brazing method for a tungsten carbide die punching head and a steel base. According to the brazing method, the big square block brazing face of the steel base is machined and divided into 3*3mm<2> small blocks at intervals, the width of a groove between every two small blocks is preferably 3mm, and the depth of the groove is preferably 2mm; when the tungsten carbide die punching head is brazed on the steel base, the heating temperature of a whole workpiece is smaller than 650 DEG C; high-frequency heated areas are controlled, and after brazing is finished, the workpiece is cooled slowly so that internal stress of the brazing face can be reduced. The brazing method has the advantages that in the process of brazing, the size of the small blocks is very small, and therefore the strain difference of steel and tungsten carbide in the areas is very small; the process of brazing cooling is very balanced, cooling is performed from the edge of each small block to the inside, and due to the small area of each small block, synchronous cooling is basically achieved. Therefore, the stress of the whole brazing face can not be superposed, and the internal stress of brazing is reduced below 10% of the internal stress of the big square block brazing face. In the follow-up machining process, the workpiece can not be cracked and scrapped.

Description

technical field [0001] The invention relates to a mold processing method used in the powder metallurgy industry, in particular to a brazing method for a stamping head of a cemented carbide mold and a steel base. Background technique [0002] Cemented carbide is a difficult-to-process and high-value product. In the powder metallurgy industry, hard alloys must be used for the working parts of mold parts to meet the requirements. In order to save material and processing costs, steel is generally used as the base in the industry, hard alloy materials are used for the working part, and two materials with different polarities are connected together by brazing. The hard alloy stamping head 4 of the existing workpiece and the steel base 5 have a large contact area (such as Figure 4-5 shown), at the brazing temperature, the linear expansion coefficient of the steel base and the cemented carbide stamping head differs by more than two times, resulting in a large difference in deformat...

AI Technical Summary

Problems solved by technology

At the initial stage of welding, various stresses reach a macro balance, and in the subsequent processing process, a large amount of stress will be released, resulting in processing cracks

[0007] Therefore, the existing method of direct brazing connection between the stamping head of the cemented carbide die and the steel base is mainly applied to workpieces with small welding surfaces. Workpiece cracked and scrapped

Images