Increasing the durability of drill bit teeth by changing its manufacturing technology

Introduction. The development of the mining industry requires increasing the durability and safe tool performance life. For bits of mining drilling machines, this problem is often solved by improving the material of the teeth of these bits. The paper presents the results of a study on the development of a technology for the manufacture of hard-alloy drill bits with increased wear resistance and testing of prototypes when drilling hard rocks. Changes in technology have led to changes in the shape of the tooth. Also, purer tungsten powder was used as the initial component. Research methods. The paper studies carbide teeth of bits manufactured at JSCAlmalykMining and Metallurgical Combine using standard and modified technology. Its structure and chemical composition were studied. Results and discussion. New methods for performing technological operations for the manufacture of carbide teeth (pins) and steel pin bits are developed and mastered. Tungsten- cobalt teeth were manufactured using VK10KS (90 %W; 10 % Co ) hard alloy, produced using tungsten carbide powder synthesized by carbidization of purified tungsten powder. The shape of the tooth surface was changed from ballistic to semi-ballistic. Metallic cobalt powder was used as a binder. Pin bits of the KNSh40x25 type are made of 0.35 C-Cr-Mn-Si steel. Tests of experimental bits were carried out at several mines, as a result of which its suitability for drilling rocks with a hardness off` = 14-18 was established. The results of industrial operation showed that the durability of the teeth of bits manufactured by JSC Almalyk Mining and Metallurgical Combine is not significantly inferior to bits from European manufacturers. At the same time, the cost of such bits is several times lower.