Features of chip forming when turning hardened steel 30HGSA with inserts coated by multi-component metal nitrides

The paper presents an analysis of the influence of multi-component coatings based on metal nitrides of various thickness deposited using of physical vapour deposition - PVD method on the values of chip thickness compression ratio […], shear angle […], shear strain […] and mean coefficient of friction on the rake face when turning of C45 steel and hardened 30HGSA steel with coated inserts made of cemented carbide. The research proves a positive influence of the tested coatings and their thickness on the tested characteristics; among others, they provide a decrease of the […] value of about 15% and the value of 10%. In order to improve the cutting conditions, a proper selection of both types of coatings and their thickness depending on the processed material is necessary.