Provided are stainless steel for a separator of a polymer electrolyte membrane fuel cell, which exhibits enhanced hydrophilicity and enhanced corrosion resistance, and a method of manufacturing the same. In the stainless steel for a separator of a polymer electrolyte membrane fuel cell, which exhibits enhanced hydrophilicity and enhanced corrosion resistance, according to an embodiment of the present invention, a ratio of Cr hydroxide/Cr oxide included in a passivation film of the stainless steel ranges from 0.5 to 1.7, and the passivation film has a contact angle (θ) of 70° or less. Thus, not only corrosion resistance may be enhanced by removing a non-conductive film formed on a surface of the stainless steel and forming a new conductive film thereon, but hydrophilicity may also be secured without additional surface treatment such as a separate coating or the like, and thus manufacturing costs may be reduced and productivity may be increased.

Provided are stainless steel for a separator of a polymer electrolyte membrane fuel cell, which exhibits enhanced hydrophilicity and enhanced corrosion resistance, and a method of manufacturing the same. In the stainless steel for a separator of a polymer electrolyte membrane fuel cell, which exhibits enhanced hydrophilicity and enhanced corrosion resistance, according to an embodiment of the present invention, a ratio of Cr hydroxide/Cr oxide included in a passivation film of the stainless steel ranges from 0.5 to 1.7, and the passivation film has a contact angle (θ) of 70° or less. Thus, not only corrosion resistance may be enhanced by removing a non-conductive film formed on a surface of the stainless steel and forming a new conductive film thereon, but hydrophilicity may also be secured without additional surface treatment such as a separate coating or the like, and thus manufacturing costs may be reduced and productivity may be increased.

Provided is a low-cost cold rolled steel sheet for zirconium-based chemical conversion treatment that contains Si and Mn and has excellent zirconium-based chemical convertibility even when a relatively large amount of Si-based oxide and Si—Mn-based oxide exists on the steel sheet surface. A cold rolled steel sheet for zirconium-based chemical conversion treatment comprises a chemical composition containing, in mass %, C: 0.05% to 0.30%, Si: 0.01% to 1.4%, Mn: 0.14% to 3.2%, P: 0.10% or less, and S: 0.01% or less, with a balance consisting of Fe and inevitable impurities, wherein a Si/Mn mass ratio in steel is 0.10 to 0.7, and a surface coating ratio of steel sheet surface layer oxides having Si content of 10 mass % or more is 40% or less.

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.

A surface treatment agent including a compound (P) represented by R.sup.1—P(═O) (OR.sup.2) (OR.sup.3) in which R.sup.1 is an alkyl group, an alkoxy group, a fluorinated alkyl group, or an aromatic hydrocarbon group which may have a substituent, and R.sup.2 and R.sup.3 are each independently a hydrogen atom, an alkyl group, a fluorinated alkyl group, or an aromatic hydrocarbon group which may have a substituent; a compound (S) represented by R—SH . . . in which R is an alkyl group having 3 or more carbon atoms, a fluorinated alkyl group having 3 or more carbon atoms, or an aromatic hydrocarbon group which may have a substituent; and a solvent.

A process for providing a surface of aluminum containing materials with a chromate-free protective coating includes degreasing a surface of an aluminum containing material to produce a degreased surface, treating the degreased surface in a high alkaline treatment immediately subsequent to the degreasing to produce an alkaline treated surface having smut on the surface, and treating the alkaline treated smut surface with a hydrothermal treatment immediately subsequent to the high alkaline treatment.

A preparation method for adhesive bonding of magnesium-containing aluminum alloy products includes a magnesium-containing aluminum alloy product including a matrix and a surface oxide layer overlying the matrix. The magnesium-containing aluminum alloy product also includes intermetallic particles at least proximal the surface oxide layer. The method also includes ablating at least some of the intermetallic particles via an energy source, and in the absence of melting of the matrix of the magnesium-containing aluminum alloy product.

A preparation method for adhesive bonding of magnesium-containing aluminum alloy products includes a magnesium-containing aluminum alloy product including a matrix and a surface oxide layer overlying the matrix. The magnesium-containing aluminum alloy product also includes intermetallic particles at least proximal the surface oxide layer. The method also includes ablating at least some of the intermetallic particles via an energy source, and in the absence of melting of the matrix of the magnesium-containing aluminum alloy product.

Described herein is a water-based, alkaline cleaner concentrate for producing a cleaner for metallic surfaces, the concentrate including a) at least one (meth)acrylic acid homopolymer having a weight-average molar mass in the range from 3 000 to 19 000 g/mol and b) at least one (meth)acrylic acid copolymer having a weight-average molar mass in the range from 50 000 to 100 000 g/mol. Also described herein are a corresponding cleaner for metallic surfaces with reduced pickling erosion, a process for anticorrosive treatment of metallic surfaces that includes a corresponding cleaning step, a metallic surface obtained by the process, and a method of use thereof in the sector of the metalworking industries.

What is provided is a new and improved metal-carbon fiber reinforced resin material composite in which the galvanic corrosion of dissimilar materials of a metal member is suppressed and electrodeposition coatability is excellent and a method for manufacturing the metal-carbon fiber reinforced resin material composite. A metal-carbon fiber reinforced resin material composite according to the present invention has a metal member, a resin coating layer disposed on at least a part of a surface of the metal member, and a carbon fiber reinforced resin material containing a matrix resin and a carbon fiber material present in the matrix resin, the resin coating layer contains any one or more kinds selected from the group consisting of metal particles, intermetallic compound particles, conductive oxide particles, and conductive non-oxide ceramic particles as conductive particles and further contains a binder resin, and the conductive particles have a powder resistivity at 23° C. to 27° C. of 7.0×10.sup.7 Ω.Math.cm or less and contain one or more selected from the group consisting of Zn, Si, Zr, V, Cr, Mo, Mn, and W.