METHOD FOR PRODUCTION OF PHOSPHATABLE PARTS FROM SHEET STEEL WITH ALUMINUM-BASED COATING Russian patent published in 2019 - IPC C23C2/12 C23C2/28 C23C28/00 C21D1/673 

FIELD: manufacturing technology.

SUBSTANCE: invention relates to production of hardened parts from sheet steel with aluminum-based coating. Method involves production of sheet steel with preliminary applied metal coating, containing 4.0 to 20.0 wt% zinc, 1.0 to 3.5 wt% silicon, optionally 1.0 to 4.0 wt% magnesium and optionally additional elements selected from Pb, Ni, Zr or Hf, and the balance is aluminum and unavoidable impurities, wherein Zn/Si ratio is in range from 3.2 to 8.0, obtaining a workpiece, its heat treatment at temperature in range from 840 to 950 °C for obtaining completely austenitic microstructure in steel, hot molding of billet for part production, part cooling to produce steel microstructure, which is martensite or martensite-bainitic or formed from at least 75 % equiaxed ferrite, from 5 to 20 % of martensite and bainite in amount of less than or equal to 10 %, and phosphating.

EFFECT: invention enables to obtain a phosphated hardened part with high degree of surface phosphate crystal coating and good adhesion to the paint coat.

29 cl, 3 tbl, 3 ex, 1 dwg