METHOD OF ION NITRIDING OF CUTTING TOOL MADE OF ALLOYED STEEL Russian patent published in 2017 - IPC C23C8/38 C23C14/48 

FIELD: metallurgy.

SUBSTANCE: method of ion nitriding of the cutting tool made of alloy steel includes placing the cutting tool in a working chamber, activating its surface before ion nitriding, feeding working saturating medium into the chamber, heating the cutting tool up to nitriding temperature and its holding at this temperature up to required thickness of diffusion layer. Activation of the cutting tool surface before ion nitriding is carried out by ion-implantation treatment of the tool cutting edges by ytterbium ions or ytterbium and nitrogen ions at ion energy from 20 to 25 keV, radiation dose of 1.2⋅10¹⁷ cm^-2 up to 2.0⋅10¹⁷ cm^-2. In particular cases, ion nitriding is carried out until the thickness of nitrided layer in the range of 12 mcm to 30 mcm is produced. After ion nitriding, a multilayer coating is applied from alternating layers of titanium and titanium nitride or titanium and titanium-aluminium nitride with thickness of titanium layer 0.3…0.4 mcm and the thickness of the layer of titanium nitride or titanium-aluminium nitride 1.0…2.0 mcm, with total thickness of the multilayer coating from 10 mcm to 16 mcm. Ion implantation, ion nitriding and application of the multilayer coating are carried out in one process cycle of the vacuum plant.

EFFECT: increased wear resistance of the cutting tool.

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