摘要 |
FIELD: process engineering.SUBSTANCE: invention relates to machine building and may be used for surface hardening of inner surfaces, for example, central bores of tubes with openings and slots and unstable initial micro- and macro-geometry and irregular mechanical properties of surface layer. Proposed method comprises feeding the balls on the surface and application of electric field thereon. Note here that treatment is carried out in gas-fluid medium at electric current voltage of 2-5 V in two steps. At first step 150-200 mcm-dia micro-balls are forced to processed surface at the angle of not over 60 degrees and compressed air pressure of 0.2-0.4 MPa for 30 seconds while, at second step, 50 mcm-dia micro-balls are forced to processed surface at compressed air pressure not exceeding 0.3 MPa for 15 seconds.EFFECT: uniform surface hardening, ruled out micro cracks.2 cl, 3 dwg, 1 ex |