Disclosed is a method of manufacturing a stainless steel with excellent contact resistance for a polymer fuel cell separator. The method of manufacturing a stainless steel with excellent contact resistance for a polymer fuel cell separator according to an embodiment of the present disclosure includes: electrolyzing to remove a first passivation film formed on a cold-rolled thin sheet of a stainless steel comprising, in percent (%) by weight of the entire composition, C: greater than 0 to 0.1%, N: greater than 0 to 0.02%, Si: greater than 0 to 0.25%, Mn: greater than 0 to 0.2%, P: greater than 0 to 0.04%, S: greater than 0 to 0.02%, Cr: 22 to 34%, Ti: greater than 0 to 0.5%, Nb: greater than 0 to 0.5%, the remainder of iron (Fe) and other inevitable impurities; and immersing in a mixed acid solution of nitric acid and hydrofluoric acid to form a second passivation film on the stainless cold-rolled thin sheet.

Disclosed is a method of manufacturing a stainless steel with excellent contact resistance for a polymer fuel cell separator. The method of manufacturing a stainless steel with excellent contact resistance for a polymer fuel cell separator according to an embodiment of the present disclosure includes: electrolyzing to remove a first passivation film formed on a cold-rolled thin sheet of a stainless steel comprising, in percent (%) by weight of the entire composition, C: greater than 0 to 0.1%, N: greater than 0 to 0.02%, Si: greater than 0 to 0.25%, Mn: greater than 0 to 0.2%, P: greater than 0 to 0.04%, S: greater than 0 to 0.02%, Cr: 22 to 34%, Ti: greater than 0 to 0.5%, Nb: greater than 0 to 0.5%, the remainder of iron (Fe) and other inevitable impurities; and immersing in a mixed acid solution of nitric acid and hydrofluoric acid to form a second passivation film on the stainless cold-rolled thin sheet.

The present invention relates to a method for adjusting a passivation composition by determining the redox potential of a passivation composition as well as to a method for passivating metallic substrates by treatment with a passivation composition.

The present invention relates to a method for adjusting a passivation composition by determining the redox potential of a passivation composition as well as to a method for passivating metallic substrates by treatment with a passivation composition.

Porous, binderless ceramic surface modification materials are described, and applications of use thereof. The ceramic surface material is in the form of an interconnected network of porous ceramic material on a substrate. The ceramic material may include a metal oxide, a metal hydroxide, and/or hydrates thereof, or a metal carbonate or metal phosphate, on a substrate surface. The substrate may be in the form of a metal or polymer particulate, powder, extrudate, or flakes.

Porous, binderless ceramic surface modification materials are described, and applications of use thereof. The ceramic surface material is in the form of an interconnected network of porous ceramic material on a substrate. The ceramic material may include a metal oxide, a metal hydroxide, and/or hydrates thereof, or a metal carbonate or metal phosphate, on a substrate surface. The substrate may be in the form of a metal or polymer particulate, powder, extrudate, or flakes.

A diphase stainless steel chemical vessel ballast cabin bulkhead includes a front cover, a rear cover and reinforced string boards. The front cover and the rear cover are distributed parallel with each other. The front cover and the rear cover are inter-connected by the reinforced string boards. The reinforced string board includes a deformation groove and connection plates, and the connection plates are distributed on two sides of the deformation groove symmetrically with respect to a central line of the deformation groove. The reinforced string boards are evenly distributed between the front cover and the rear cover; the reinforced string boards and an axis of the front cover and the rear cover are distributed parallel. Adjacent reinforced string boards are mutually connected. A thickness of the front cover is at least one time thicker than that of the rear cover. The processing method thereof includes three steps.

A diphase stainless steel chemical vessel ballast cabin bulkhead includes a front cover, a rear cover and reinforced string boards. The front cover and the rear cover are distributed parallel with each other. The front cover and the rear cover are inter-connected by the reinforced string boards. The reinforced string board includes a deformation groove and connection plates, and the connection plates are distributed on two sides of the deformation groove symmetrically with respect to a central line of the deformation groove. The reinforced string boards are evenly distributed between the front cover and the rear cover; the reinforced string boards and an axis of the front cover and the rear cover are distributed parallel. Adjacent reinforced string boards are mutually connected. A thickness of the front cover is at least one time thicker than that of the rear cover. The processing method thereof includes three steps.

A method for post-treatment of a chromium finish surface to improve corrosion resistance comprising a) providing a substrate having a chromium finish surface, and at least one intermediate layer between the chromium finish surface and the substrate, selected from the group consisting of nickel, nickel alloys, copper and copper alloys, wherein the chromium finish surface is a surface of a trivalent chromium plated layer, obtained by electroplating the substrate, having the at least one intermediate layer, in a plating bath, the plating bath comprising chromium (III) ions; b) contacting the chromium finish surface with an aqueous solution, comprising a permanganate, at least one compound which is selected from a phosphorus-oxygen compound, a hydroxide, a nitrate, a borate, boric acid, a silicate, or a mixture of two or more of these compounds; c) forming a transparent corrosion protection layer onto the chromium finish surface during step b.

An aqueous solution for metal surface treatment includes an alkyl silicate or an oligomer thereof in a concentration of 0.005 mass % or more and less than 1 mass %, and an organic silane compound in a concentration of 0.005 mass % or more and less than 1 mass %. The aqueous solution has a pH of 2 or more and 7 or less.