A kind of low-cobalt cemented carbide and the method for reducing the welding crack of low-cobalt cemented carbide

Abstract

The invention discloses a method for reducing weld cracks of low-cobalt hard alloy. The method is characterized by comprising the steps that a sintering area in a sintering furnace is divided, and thesintering position of the low-cobalt hard alloy is determined; a pressed blank with a corresponding carbon balance coefficient is prepared according to the sintering position of the low-cobalt hard alloy; a sintering boat is arranged at the sintering position of the low-cobalt hard alloy, wherein the height of the boat is larger than the height of the pressed blank; the pressed blank is placed into the sintering boat to be sintered; and whether the relative magnetic saturation of the sintered alloy meets a set value or not is measured, and sintering is repeated until the relative magnetic saturation of the alloy reaches the set value. The surface modification process carried out after low-cobalt alloy preparation is omitted, the crack phenomenon occurred when a hard alloy blade and the steel are welded is improved, and the welding performance of the low-cobalt hard alloy is improved.

Description

technical field [0001] The invention belongs to the field of cemented carbide welding, in particular to a method for reducing cracks in low-cobalt cemented carbide welding. Background technique [0002] Cemented carbide is an alloy material made of hard compounds of refractory metals and bonding metals through powder metallurgy. Due to its high hardness and excellent wear resistance, it is widely used in cutting fields such as 3C (China Compulsory Product Certification), wood processing and metal processing. Low-cobalt cemented carbide has a high content of hard phase and less content of binder phase, which has higher hardness and better wear resistance than ordinary cemented carbide. Due to the scarcity of resources and high price, in order to save costs, this type of alloy is usually welded with steel before cutting. The thermal expansion coefficient of cemented carbide and steel differs by several times, especially for low-cobalt alloys, the increase in hard phase conte...

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Problems solved by technology

[0003] The existing cemented carbide is sintered at any position in the sintering furnace during sintering, and its cobalt content is above 4%. The allowable cobalt magnetic fluctuation range of the alloy is relatively large, and it is relatively easy to carry out mass production

The cobalt content of low-cobalt cemented carbide is low (less than 4%), and its allowable cobalt magnetic fluctuation range is small, and it is difficult to control the pass rate of products in production; in addition, the thermal expansion coefficient between low-cobalt cemented carbide and steel The difference is greater, and welding cracks are more likely to occur during welding

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