TREATMENT OF SURFACE FOR ENHANCING CORROSION RESISTANCE OF AUSTENITIC STAINLESS STEELS Russian patent published in 2005 - IPC

FIELD: chemical pickling of metal materials; treatment of surfaces made from austenitic stainless steels and articles made from such steels, for example, strips, bars, sheets and pipes.

SUBSTANCE: proposed method includes removal of adequate amount of material from steel surface by acid pickling for obtaining surface with crevice corrosion at critical temperature exceeding x, where x (°C)= 3.2 (mass-% Cr)+7.6 (mass-% Mo)+10.5 (mass-% N)-88.5. Austenitic stainless steel has equivalent number of resistance to pitting corrosion not exceeding 52.6 at critical temperature of at least 38°C. Material may be removed from part of surface by any method, including sandblasting by abrasive particles, grinding and/or acid pickling under more aggressive conditions as compared with usual treatment of such steels.

EFFECT: enhanced corrosion resistance without modification of chemical composition of steel.

26 cl, 8 dwg, 4 tbl