In order to improve the physical and mechanical properties
of cutting tools made of P6M5 steel, the article presents the results of a
study of the possibility of using a combined method of nitrooxidation,
consisting of nitriding in ammonia at the first stage and oxidation in water
vapor at the second stage.
The formation of nitride-oxide coating compositions with the
formation of a thin dense oxide film and a nitride layer under it, depending on
the holding time, undergoes structural and phase transformations during the
oxidation process with the transition of low nitrides doped with carbon and
oxygen, as well as an internal nitriding zone following it.
It has been established that during the oxidation process,
an oxide layer with a nitride sublayer or zones of internal nitriding with
supersaturated nitrogen can be formed on the surface, allowing the production
of stable nitrides of both the base metal and alloying elements.
By regulating the parameters of the nitrooxidation process
on alloyed steels, compositions with different structural and phase states can
be formed that have the best physical and mechanical properties than the
nitride layer obtained by traditional nitriding methods.
For surface hardening of cutting tools, it is necessary to
obtain a nitride-oxide layer with a thin oxide layer on the surface and a
nitride sublayer consisting of low-nitrogen nitrides alloyed with carbon and
oxygen with a developed sublayer of the internal nitriding zone.
The oxide layer, together with the subsequent arrangement of
the nitride layer on the surface of the internal hardness nitriding zone,
successfully provides a positive gradient of surface properties under external
friction conditions and has the best ductility in terms of ensuring wear
resistance.
Author(s) Details
Kholikul Eshkabilov
Karshi Engineering Economic Institute, 225, Mustaqillik
Avenue, Karshi City-180100, Uzbekistan.
https://orcid.org/0009-0003-4538-9590
Please see the book here:- https://doi.org/10.9734/bpi/caert/v5/847
