Вплив неоднорідності високоміцного чавуну на характер зносу різців із різних інструментальних матеріалів

Abstract

UA: Із високоміцного чавуну виготовляють важконавантажені деталі транспортних засобів, які повинні мати високий рівень експлуатаційних властивостей, що погіршує їх оброблюваність різанням. У роботі показано, що вирішальний вплив на стійкість інструментів із різних інструментальних матеріалів має неоднорідність чавуну, що підтверджено якісним аналізом поверхонь зносу і результатами стійкісних випробувань і розрахунками режиму різання.

EN: High-strength spheroidal graphite cast iron is used to make heavily loaded vehicle parts that must have a high level of performance properties, which impairs their machinability. Research into the wear characteristics of tools made of hard alloy, superhard tool material and mineral ceramics and providing recommendations on cutting modes when turning products made of high-strength cast iron, taking into account its heterogeneity. The worn surfaces of the cutting inserts were examined using an ЕМ-100БР electron microscope and a РEM-200 scanning electron microscope. Studies of the wear surfaces of tools made of hard alloy ВK8, superhard tool material composite K10Д, mineral ceramics ВOK71 showed that when machining high-strength cast iron, fatigue phenomena are characteristic of all materials, which are accompanied by the formation of microcracks, chipping, and tearing. Qualitative analysis of wear surfaces and developed recommendations on cutting modes showed that the decisive influence on tool wear and machinability of high-strength cast iron is the coefficient of heterogeneity, which takes into account the complex influence of the microstructure, chemical and structural heterogeneity of cast iron, which leads to instability of the cutting process, causes oscillatory loads on the tool and intensifies its wear. There is a good correlation between the nature of tool surface wear, durability (cutting speed) and the coefficient of cast iron heterogeneity: the highest cutting speed and the lowest degree of destruction of wear surfaces are observed when processing cast iron with the lowest degree of heterogeneity, which was subjected to double normalization. For tool materials ВK8, K10Д, ВOK71, recommendations on cutting modes (cutting speed) during turning have been developed, which take into account the heterogeneity of high-strength cast iron. The highest productivity in processing products from high-temperature carbon steel is achieved by the K10Д composite.