ALUMINUM-COATED STEEL SHEET, THERMOFORMED PART AND METHODS OF MANUFACTURING Russian patent published in 2024 - IPC C23C2/12 C21D1/78 C21D8/02 C22C38/38 

FIELD: metallurgy.

SUBSTANCE: disclosed is a group of inventions comprising a steel sheet with an aluminum coating, a method of making said sheet, thermoformed part with aluminum coating, made of steel sheet with aluminum coating, and method of manufacturing said part. Said steel sheet is made with aluminum coating containing surface layer with microstructure, including Mg₂Si phase and AlMgSiFe phase. Mg₂Si phase has an average grain diameter of 0.001–5 mcm. Method of aluminum-coated steel sheet manufacturing involves steel melting, hot rolling, at which the winding temperature is 630 °C or less, continuous annealing at temperature of 710–780 °C and immersion into a melt based on aluminum containing silicon at temperature of 600–660 °C. Steel sheet is cooled to hardening temperature of aluminum coating at rate exceeding 15 °C/s. Method of manufacturing a thermoformed part with said aluminum coating includes making a workpiece from a steel sheet with an aluminum coating, heat treatment of the workpiece by means of single-stage heating or staged heating. Then, said workpiece, having temperature of 650 °C or higher, is transferred into a mold for thermoforming.

EFFECT: reduced sticking of rollers and reduced hydrogen embrittlement during thermoforming, as well as improved resistance to red rust of thermoformed part.

15 cl, 2 dwg, 3 tbl, 6 ex