Abstract: A process may be utilized to produce a galvannealed Zn—Mg hot dip coating that provides improved corrosion protection on a steel substrate, and to a flat steel product having such characteristics. To this end, a steel substrate may be subjected to hot dip coating in an Fe-saturated melt bath heated to 350-650° C., wherein the melt bath comprises in percent by weight 0.1-0.16% Al, 0.1-0.6% Mg, and also <2% Si, <1% each of Ni or Cu, <0.3% Co, <0.0001% Mn, <0.5% Sr, <0.1% each of Pb, B, Bi or Cd, <0.2% each of REM, Ti or Cr, or <0.5% Sn, with the balance being zinc and unavoidable impurities. Further, a galvannealing treatment may be conducted in which the steel substrate is kept at 450-800° C. for 10-25 seconds to produce a galvannealed Zn—Mg hot dip coating on the steel substrate. The coating may comprise Zn, unavoidable impurities, and in percent by weight 0.10-0.5% Al, 5.0-15.0% Fe, 0.10-0.8% Mg and <2 % Si, <1% each of Ni, Cu, <0.3% Co, <0.0001% Mn, <0.5% Sr, <0.

Abstract: A method for producing a steel component with a metallic anti-corrosion coating from a sheet steel product comprising at least 0.4% by weight Mn is disclosed. The sheet steel product is annealed in a continuous furnace under an annealing atmosphere containing up to 25% by volume H2, 0.1% to 10% by volume NH3, H2O, N2, and process-related impurities as the remainder, at a dew point between ?50° C. and ?5° C. at a temperature of 400 to 1100° C. for 5 to 600 s. The annealed sheet steel product has a 5 to 200 ?m thick nitration layer with a particle size finer than the particle size of the inner core layer. Once coated with a metallic protective layer, a blank is separated from the annealed sheet steel product, heated to an austenitising temperature of 780 to 950° C., hot-formed, and cooled so that a hardened structure forms.

Abstract: The present invention relates to a method for the manufacture of galvannealed metal sheet, wherein a hot strip is produced from an IF steel containing 0.01 to 0.1 wt. % silicon, wherein the hot strip is coiled at a coiler temperature no lower than 700° C. and no higher than 750° C., wherein a cold strip is rolled from the coiled hot strip, wherein the cold strip is recrystallization-annealed in an annealing furnace in an annealing gas atmosphere, wherein the cold strip thus annealed is provided with a zinc coating in a zinc bath, and wherein the coated cold strip is post-annealed at a galvannealing temperature no lower than 500° C. and no higher than 540° C. The invention also relates to a galvannealed metal sheet which possesses improved adhesion of the coating layer to the base material and proposes a method which is suited for the manufacture of metal sheet having such properties.

Abstract: The present invention relates to a method for the manufacture of galvannealed metal sheet, wherein a hot strip is produced from an IF steel containing 0.01 to 0.1 wt. % silicon, wherein the hot strip is coiled at a coiler temperature no lower than 700° C. and no higher than 750° C., wherein a cold strip is rolled from the coiled hot strip, wherein the cold strip is recrystallisation-annealed in an annealing furnace in an annealing gas atmosphere, wherein the cold strip thus annealed is provided with a zinc coating in a zinc bath, and wherein the coated cold strip is post-annealed at a galvannealing temperature no lower than 500° C. and no higher than 540° C. The invention also relates to a galvannealed metal sheet which possesses improved adhesion of the coating layer to the base material and proposes a method which is suited for the manufacture of metal sheet having such properties.