METHOD OF PREPARATION OF SURFACES OF METAL ARTICLES BEFORE COLD DEFORMATION Russian patent published in 2005 - IPC

FIELD: preparation of surfaces of metal articles for cold deformation (cold extrusion, upsetting of fasteners, wire drawing); metallurgy; mechanical engineering; production of calibration metal and machine parts.

SUBSTANCE: proposed method includes activation, phosphatization and saponification; activation of surface is performed in aqueous solution of sodium nitrite at concentration of 0.1-0.5 g/l and temperature 85-95°C for 2 min by immersing in activating solution; phosphatization is performed in aqueous solution of phosphating concentrate at the following ratio of components, g/l: zinc ions, 9.6-28.16; phosphorus anhydride, 6.08-20.46; nitrate ions, 13.2-41.8; nickel ions, 0.0320.132; fluorine ions, 0.128-0.528 and hydroxylamine sulfate, 1.6-5.72; the process is performed by dipping into phosphating solution at temperature of 75-80°C for 10 min; saponification is performed in stearate solution at concentration of 40 g/l and temperature of 85-95°C for 5 min; surface density of phosphate coat is equal to 0.06-1.0 g/dm² and mass of soap is equal to 0.05-0.2 g/dm². Punch was replaced after treatment of 70,000 articles.

EFFECT: smooth force at extrusion; avoidance of scores and sticking of metal on tools; enhanced durability of stamping equipment and tools.

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