Hot rolled and coated steel sheets for hot stamping, hot stamped and coated steel parts and methods for producing them

摘要

A method for producing a hot-rolled and coated steel sheet having a thickness between 1.8 mm and 5 mm, wherein 0.04% ≦ C ≦ 0.38%, 0.40% ≦ Mn ≦ 3. %, 0.005% ≦ Si ≦ 0.70%, 0.005% ≦ Al ≦ 0.1%, 0.001% ≦ Cr ≦ 2%, 0.001% ≦ Ni ≦ 2%, 0.001% ≦ Ti ≦ 0.2%, Nb ≦ 0.1%, B ≦ 0.010%, 0.0005% ≦ N ≦ 0.010%, 0.0001% ≦ S ≦ 0.05%, 0.0001% Preparing a semi-finished product having a composition containing ≦ P ≦ 0.1%, Mo ≦ 0.65%, W ≦ 0.30%, Ca ≦ 0.006%, Rolling to obtain a hot-rolled steel product having a thickness between 1.8 mm and 5 mm, and then winding the hot-rolled steel product at a winding temperature Tc chilled to a hot rolled steel product to obtain a hot rolled steel substrate, wherein the winding temperature Tcoil is 450 ° C. ≦ Tcoil ≦ Tcoilmax (where Tcoilmax is expressed as Pickling hot rolled steel substrate, satisfying Tcoilmax, expressed in degrees Celsius, fγ represents the austenite fraction just before winding, in the bath Coating the hot-rolled steel substrate with Al or Al alloy by continuous hot-dip plating, and having a thickness included between 10-33 μm on each surface of the hot-rolled steel sheet and the hot-rolled steel sheet A method comprising hot rolling comprising an Al or Al alloy coating and obtaining a coated steel sheet.