GALVANISED HOT DIPPING AND ALLOYED STEEL SHEET AND METHOD OF ITS MANUFACTURE Russian patent published in 2017 - IPC C22C38/06 C22C38/04 C21D9/46 C21D8/02 C23C2/02 C23C2/06 C23C2/28 

FIELD: metallurgy.

SUBSTANCE: hot dip galvanized and alloyed sheet includes a base steel sheet, a layer of galvanic coating 3-30 mcm thick on the surface of base steel sheet and a-layer with thickness of 2-20 mcm formed directly under the surface of base steel sheet. The base sheet is made of steel containing, wt %: C 0.05-0.50, Si 0.2-3.0, Mn 0.5-5.0, Al 0.001-1.0, P 0.1 or less, S 0.01 or less, N 0.01 or less, Fe and unavoidable impurities is the rest. The layer of galvanic coating formed by hot dipping and alloying contains, wt %: and unavoidable impurities is the rest. The A-layer has a structure containing 50% or more by volume of ferrite and the rest is unavoidable structures including bainite, martensite, residual austenite, pearlite. The A-layer has, based on the mass of A-layer, the content of unoxidized 90 wt % or more, the total content of Fe, Si, Mn, P, S and Al oxides of 10 wt % or less and C content of less than 0.05 wt %.

EFFECT: hot dip galvanized and alloyed sheet has high strength, high wetting ability of the cladding coating, and adhesion of the cladding layer.

5 cl, 11 dwg, 3 tbl