A method for forming a coating, which includes: a first step of applying a first solution containing a polysilazane to a surface of a metal substrate, heating the first solution to make the first solution undergo conversion into silica and form a first coating having open defects, on the surface of the metal substrate, and a second step of applying a second solution containing a polysilazane to a surface of the first coating 1 to fill the open defects, and heating the second solution at a temperature lower than a heating temperature in the first step to make the second solution undergo conversion into silica and form a second coating on a surface of the first coating.

Processes for the anti-corrosion pre-treatment of a plurality of components in series, in which each component in the series at least partly has surfaces of zinc and/or iron and at least parts of these surfaces are firstly activated in a targeted manner for subsequent zinc phosphating are provided with targeted activation achieved by means of controlled dispensing of an aqueous dispersion to wet zinc and/or iron surfaces, thus ensuring resource-saving activation; the aqueous dispersion for activation wetting contains a particulate constituent dispersed in water, which is at least partially composed of hopeite, phosphophyllite, scholzite and/or hureaulite and provided as a dispersion of these crystalline solids, stabilized by at least one polymeric organic compound; followed by a zinc phosphating bath comprising a quantity of an aqueous dispersion, in particular the same aqueous dispersion that is used for activation wetting.

Processes for the anti-corrosion pre-treatment of a plurality of components in series, in which each component in the series at least partly has surfaces of zinc and/or iron and at least parts of these surfaces are firstly activated in a targeted manner for subsequent zinc phosphating are provided with targeted activation achieved by means of controlled dispensing of an aqueous dispersion to wet zinc and/or iron surfaces, thus ensuring resource-saving activation; the aqueous dispersion for activation wetting contains a particulate constituent dispersed in water, which is at least partially composed of hopeite, phosphophyllite, scholzite and/or hureaulite and provided as a dispersion of these crystalline solids, stabilized by at least one polymeric organic compound; followed by a zinc phosphating bath comprising a quantity of an aqueous dispersion, in particular the same aqueous dispersion that is used for activation wetting.

Provided is a method of producing a grain-oriented electrical steel sheet having uniform and good coating properties and magnetic properties throughout the length and/or width of the steel sheet. The method comprises: subjecting a steel slab to hot rolling, to cold rolling once or twice or more with intermediate annealing therebetween, and to primary recrystallization annealing; applying a liquid or slurry annealing separator to a resultant steel sheet; and thereafter coiling the steel sheet and subjecting the steel sheet to final annealing, wherein, before, after, or simultaneously with the application of the annealing separator, an additive for changing a composition of the annealing separator is adhered to the steel sheet at a weight ratio of 15% or less to a total of the annealing separator and the additive so as to vary the composition of the annealing separator in a longitudinal direction and/or width direction of the steel sheet.