STEEL TOOL SURFACE STRENGTHENING METHOD Russian patent published in 2018 - IPC C21D1/78 C23C26/00 

FIELD: metallurgy.

SUBSTANCE: present invention relates to metallurgy, namely to methods for hardening the final manufactured steel parts of machines and tools without changing their original dimensions and structure. Method for hardening the surface of a steel tool includes preliminary preparation of the surface of a steel tool, hydrochemical treatment of the said steel tool in a medium based on a component forming a strengthening phase on the steel surface, and final heating. Hydrochemical treatment is carried out for 40-100 minutes in a boiling water-dispersed alkaline medium containing a component forming a nano-oxide strengthening phase on a steel surface in the form of a nanooxide with a concentration of 0.5-50 g/l and a surfactant in the form of glycerin at a concentration of 0.5-50 g/l with the addition of aqueous ammonia, and final heating of the steel tool is carried out in an air atmosphere at a temperature of 140-200°C. In particular embodiments of the invention, nanooxide of tin, manganese, silicon, lead, cobalt, nickel, aluminum, molybdenum, zinc, antimony, vanadium, bismuth, boron, beryllium, zirconium, iron, chromium, tungsten, titanium or copper is used. In treated tools, a composite structure is provided for the implementation of the dual nature of hardening.

EFFECT: on the surface a nanooxidic solid lubricating coating is deposited with a very low coefficient of friction and a zone of increased compressive stresses comparable to the level of stresses obtained by surface plastic deformation methods is formed in the sublayer, which significantly increases the efficiency of wear parts of steel products and tools.

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