METHOD OF HARDENING SURFACES OF METAL ARTICLES Russian patent published in 2006 - IPC C21D7/06 C23C10/12 

FIELD: mechanical engineering and metallurgy; manufacture of various parts.

SUBSTANCE: articles, steel balls and alloying agent powder are placed in closed working chamber filled with gaseous medium. Balls and powder are set in motion by means of ultrasonic field till impact with surface being treated. Ultrasonic field is formed in working chamber at vibration of its wall at preset amplitude of shift for simultaneous treatment by deforming and diffusion mass transfer of atoms of alloying agent (molybdenum carbonyl or molybdenum disulfide) to surface layer. Treatment is continued within preset time. Balls have different diameters at common mass M=1/i·(V₁-V₂)/ζm(D₁/k₁+D₂/k₂)+...D_i/k_i, where V₁ is volume of working chamber; V₂ is volume of part of article located in chamber; ζ_m is amplitude of shift of chamber wall; D₁, D₂...D_i are diameters of steel balls; k₁, k₂...k_i=(1.7-2.3)·10², cm³/g are proportionality coefficients; mass of one type of balls is found from the following formula: where i is number of used type of balls (i#1)at D₁>D₂>...D_i; mass of alloying agent is determined from the following formula: where d is average diameter of powder particles; ρ₁ and ρ₀ are densities of powder and balls, respectively; f₀ is oscillation frequency; δ_0.2 is yield point of material. In the course of treatment working medium of chamber may be heated by supplying heated gas into it.

EFFECT: enhanced efficiency.

1 dwg, 4 tbl, 1 ex