METHOD FOR MANUFACTURING PARTS FROM PRESS-HARDENED SHEET STEEL WITH ALUMINUM-BASED COATING, PRIMARY SHEET BLANK AND PRESS-HARDENED SHEET STEEL PART Russian patent published in 2023 - IPC C21D8/04 C23C2/00 B21D22/00 B21D26/21 B21D26/53 B21D26/57 B21D26/59 B21D35/00 C23C2/04 C23C2/12 C23C28/00 C21D8/00 

FIELD: sheet steel blanks and parts made from them.

SUBSTANCE: invention relates to a method for manufacturing a primary blank and to a part hardened under a press, formed from a primary blank. The method includes the following steps: obtaining at least two sections of a steel strip with an aluminum-based coating having different sheet thicknesses, welding sections of the steel strip to each other to obtain a primary blank, while the primary blank has a different sheet thickness, with the thinnest and thickest section sheet, before or after welding said sections of the steel strip to each other, applying an inorganic iron-containing conversion layer locally or on the entire surface of an aluminum-based coating with a layer weight ratio to iron of 3-30 mg/m², at least in the region of the thickest section sheet. A press-hardened part made from an original workpiece, in which a diffusion zone is formed between the steel substrate and the main layer of the aluminum-based coating, consisting of the metals of the main coating layer and the steel substrate, while the diffusion zones in areas of different sheet thickness, with respect to the original workpiece, have a maximum thickness difference that corresponds to the following ratio: DImax ≤ 8*((D1-D2)/D1), where D1: the thickest section of the sheet of the primary blank; D2: the thinnest section of the sheet of the primary blank; DImax: maximum difference in the thickness of the diffusion layer on the hardened part.

EFFECT: ability to varnish and weldability in all areas of the part obtained from the original workpiece.

19 cl, 8 dwg, 1 tbl