A method for producing a hot-pressed member includes heating a coated steel sheet, which includes, on a surface thereof, a ZnNi alloy coating layer containing 10% by mass or more and less than 13% by mass of Ni at a coating weight of over 50 g/m.sup.2 per side of the steel sheet, in a temperature region of an Ac.sub.3 transformation point to 1200 C. at an average heating rate of 12 C./second or more, and then hot-pressing the steel sheet.

A process for manufacturing a flat steel product having a prealloyed corrosion-resistant coating, comprises providing a coated flat steel product comprising a steel substrate having, at least on one side of the steel substrate, and an aluminum-based corrosion-resistant coating. The coated flat steel product is heat-treated, comprising the following substeps: Heating the coated flat steel product in a furnace at a furnace temperature T of between 950 C. and 1150 C. with a furnace dwell time t.sub.V of between 40 seconds and 150 seconds, the furnace temperature being chosen such that the heating rate of the coated flat steel product in the temperature range from 500 C. to 700 C. is more than 10 K/s. The coated flat steel product is held at a temperature above Ac3 for a hold time of between 20 seconds and 60 seconds.

A hot-pressed steel sheet member includes a specific chemical composition and further includes a steel structure in which an area ratio of ferrite in a surface layer portion ranging from a surface to 15 m in depth is greater than 1.20 times an area ratio of ferrite in an inner layer portion being a portion excluding the surface layer portion, and the inner layer portion contains a steel structure represented, in area %, ferrite: 10% to 70%, martensite: 30% to 90%, and a total area ratio of ferrite and martensite: 90% to 100%. A tensile strength of the hot-pressed steel sheet member is 980 MPa or more.

A method for producing a steel sheet for packaging includes: cold-rolling a hot-rolled steel sheet made from a steel having a carbon content of 10 to 1000 ppm by weight, the steel of the hot-rolled steel sheet having a predetermined recrystallization temperature (T.sub.R); heating the cold-rolled steel sheet to a predetermined heating temperature (T.sub.E), where T.sub.RT.sub.E, the heating performed at least partially in the presence of a nitrogen donor at least until T.sub.R is reached such that when the cold-rolled steel sheet is heated, nitrogen from the nitrogen donor is diffused at least into a near-surface region of the cold-rolled sheet steel and incorporated in the near-surface region, as a result of which the T.sub.R in the near-surface region is increased by a value T, where T.sub.E<T.sub.R+T. Using this method, high-strength steel sheets having a multilayer microstructure can be produced.