METHOD OF PRODUCTION OF PARTS HARDENED UNDER PRESS FROM STEEL SHEETS OR STEEL TAPES WITH ALUMINUM-BASED COATING AND PART HARDENED BY PRESS FROM THEM Russian patent published in 2019 - IPC C23C2/12 C23C2/26 C23C2/28 C23C2/40 C23C8/36 C23C28/00 C21D9/46 C25D11/04 

FIELD: metallurgy.

SUBSTANCE: invention relates to production of parts hardened under press from steel sheets or steel tapes with aluminum-based coating. Disclosed is a method in which a steel-based aluminum-based coating layer is applied on a steel sheet or a steel strip by hot dipping, after which prior to forming process, steel sheet or steel tape with main coating layer is subjected to plasma oxidation and/or treatment with hot water and/or steam treatment, and on surface of main layer of coating by formation of oxides or hydroxides form surface layer containing oxide and/or aluminum hydroxide. Also disclosed is a method in which a base layer is applied by hot immersion from a molten bath with silicon content of 8 to 12 wt%, iron from 1 to 4 wt%, the rest is aluminum, and after hot dipping and before forming process steel sheet or steel tape with main coating layer is subjected to anodic oxidation, and on surface of main layer of coating by formation of oxides or hydroxides form surface layer containing oxide and/or aluminum hydroxide. In the methods, steel sheet or steel strip for tempering is heated at least in some places to temperature higher than Ac3, then at this temperature, critical cooling rate is formed and then cooled at a rate exceeding, at least in some places.

EFFECT: method is proposed for production of parts hardened under press from steel sheets or steel tapes with aluminum-based coating and part hardened under press from them.

13 cl, 3 dwg