MODELING OF IMPACT OF CENTRIFUGAL REINFORCEMENT MODES ON WEAR OF CUTTER TEETH OF DRILL BITS

Abstract

A study was performed to improve the performance of drill bits. It is noted the main work item are cones, equipped with serrated arms, made in the form of solid or false teeth. It is noted reinforcement of cutters during destruction of rocks is subjected to intensive wear under the action of high loads at the bottom, significant temperature differences, in the presence of abrasive particles, changes in the rock hardness. To reduce the impact of these factors on the wear of rock-destruction weapons, comprehensive design and technological measures are proposed to create a rock-destructive tool and, in particular, its reinforcement. The efficiency criterion of such events is proposed to choose resistance of rock-cutting elements to various types of wear. For implementation of the proposed approach to creating effective reinforcement, a critical analysis of the design of the cutter teeth of drill bits equipped with teeth of various designs and technologies for their manufacture was performed, and rolling cutters with plug-in teeth made by centrifugal reinforcement were selected as the object of research as the most optimal. The design of such teeth, implemented by a centrifugal casting process, provides for location of the rock-breaking hard alloy in the tooth head. The tooth root, pressed into the cutter housing, is made of steel. A mathematical model of the process of centrifugal reinforcement of cutter teeth of drill bits was developed to study the impact of process conditions on their resistance to impact-abrasive wear. As independent variables, otherwise the factors determining the technological process modes of centrifugal reinforcement were selected X₁, X₂, X₃, X₄, their main level and intervals of variation, the upper and lower levels were established. A full factor experiment 2⁴ was used in the research. An experimental plan was drawn up. In accordance with the chosen plan, 16 active experiments were performed; each experiment was repeated three times. Then, a mathematical model and its describing regression equation were developed. The impact degree of process factors on the value of shock-abrasive wear of teeth and their optimum values were determined.