HOT-ROLLED STEEL PLATE WITH APPLIED HOT-FORMING COATING, HOT-STAMPED STEEL PART WITH APPLIED COATING AND METHODS OF PRODUCTION THEREOF Russian patent published in 2020 - IPC C21D8/02 B21D22/02 C21D9/48 C22C38/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to the field of metallurgy. To increase mechanical properties of sheet steel, the method of producing hot-rolled sheet steel with applied coating, having thickness varying from 1.8 mm to 5 mm, involves producing a semi-finished product characterized by a composition containing the following in wt. %: 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 % ≤ P ≤ 0.1 %; Mo ≤ 0.65 %; W ≤ 0.30 %; Ca ≤ 0.006 %; hot rolling at finishing rolling temperature FRT to obtain hot-rolled steel product having thickness varying from 1.8 mm to 5 mm, then cooling down to rolling temperature T_coil, satisfying the following ratio: 450 °C ≤ T _coil ≤ T_coilmax at T_coilmax = 650 - 140 × f_γ, wherein T_coilmax is expressed in degrees Celsius, and f_γ denotes a portion of austenite immediately before rolling into a roll, and rolling into a coil for producing a hot-rolled steel substrate, etching and depositing a coating of Al or an Al alloy on the hot-rolled steel substrate as a result of continuous dipping into the melt in the bath for producing hot-rolled sheet steel with applied coating, containing hot-rolled sheet steel and coating from Al or Al alloy, having thickness varying from 10 to 33 mcm, on each side of hot-rolled steel plate.

EFFECT: improved mechanical properties of sheet steel.

42 cl, 4 tbl, 2 dwg