Romaniuk S. IIncreasing of durability of the thin-walled cutting tool

Based on complex theoretical and experimental investigations, a new technology of hardening of the thin-walled cutting tools by coatings from different materials has been proposed. Temperature fields generated in various zones of the thin-wall cutting tool, that undergoes the intensive wear and fatigue defectiveness is estimated theoretically. In knives from 65G steel it is 48 ° C (in the main part) and in the thinnest part, at the edge of the cutting edge, it is 575°C, and from steel 20Cr13 - does not exceed 385°C. Parameters of the covering: WC (ion - plasma method of hardening is used); CrN (vacuum - arc method) - has been defined experimentally. A constructive way of increasing the durability of thin knives by nanostructured coatings with the formation of hardness edges has been proposed. The control technology of quality and of the state of hardened layer and of worn-out layer has been developed. A new complex optical - mathematical method for estimation of structure degradation during the operation of knives has been proposed. The basic mechanical characteristics of initial and hardened cutting tool from the steel 65G has been obtained. The coating has a higher level of the nanohardness and reaches 23,19 GPa (for initial knife does not exceed 4.09 GPa). Elastic recovery is 47%. Resistance to plastic deformation of knife metal with CrN coating has increased in 93 times. Industrial tests of hardened knifes has showed the increasing of operational stability in 25 (for CrN coatings) and in 45 times (for WC).