A steel sheet with excellent phosphatability, according to one embodiment of the present invention, comprises, by wt %, 0.02-0.06% of carbon (C), 0.01% or less of silicon (Si) (excluding 0%), 0.1-0.24% of manganese (Mn), 0.02% or less of aluminum (Al) (excluding 0%), 0.015-0.04% of phosphorus (P), and the balance of iron (Fe) and inevitable impurities, and has an oxide layer having a thickness of 10 nm or less inward from the surface of the steel sheet, and satisfies the following formula 1.

([Mn]+[Si]+[Al])/(3[P])0.6 [Formula 1]

(In formula 1, [Mn], [Si], [Al] and [P] mean the maximum amount of each element when elemental analysis is carried out in the thickness direction of the oxide layer.)

This non-oriented electrical steel sheet includes a base steel sheet (10); and an insulation coating (20) formed on a surface of the base steel sheet (10), in which the insulation coating (20) contains a metal phosphate and an organic resin, an arithmetic mean of a center line average roughness Ra.sub.75 of the insulation coating (20) in a rolling direction of the base steel sheet (10) and a center line average roughness Ra.sub.75 of the insulation coating (20) in a direction perpendicular to the rolling direction is 0.20 to 0.50 ?m, and the amount of nitrogen in the insulation coating (20) is 0.05 to 5.00 mass %.

This non-oriented electrical steel sheet includes a base steel sheet (10); and an insulation coating (20) formed on a surface of the base steel sheet (10), in which the insulation coating (20) contains a metal phosphate and an organic resin, an arithmetic mean of a center line average roughness Ra.sub.75 of the insulation coating (20) in a rolling direction of the base steel sheet (10) and a center line average roughness Ra.sub.75 of the insulation coating (20) in a direction perpendicular to the rolling direction is 0.20 to 0.50 ?m, and the amount of nitrogen in the insulation coating (20) is 0.05 to 5.00 mass %.

A method of improving corrosion and mar resistance of steel components by creating a black magnetite finish, with a medium temperature process, prior to application of a phosphate layer coating.

A method of improving corrosion and mar resistance of steel components by creating a black magnetite finish, with a medium temperature process, prior to application of a phosphate layer coating.

The invention relates to the technical field of aluminum alloy surface treatment, in particular to the technical field of IPC C23C, and more specifically to a pretreatment method of an aluminum alloy coil. The invention can improve adhesion of an adhesive and weldability of an aluminum alloy at the same time through a specific pretreatment method combined with a specific treatment solution, and an aluminum alloy substrate after pretreatment has good compatibility with subsequent permanent anti-corrosion treatment, so that the pretreatment method is very suitable for welding or bonding of aluminum alloy parts of automobile bodies.

The invention relates to the technical field of aluminum alloy surface treatment, in particular to the technical field of IPC C23C, and more specifically to a pretreatment method of an aluminum alloy coil. The invention can improve adhesion of an adhesive and weldability of an aluminum alloy at the same time through a specific pretreatment method combined with a specific treatment solution, and an aluminum alloy substrate after pretreatment has good compatibility with subsequent permanent anti-corrosion treatment, so that the pretreatment method is very suitable for welding or bonding of aluminum alloy parts of automobile bodies.

This non-oriented electrical steel sheet includes a base steel sheet (10); and an insulation coating (20) formed on a surface of the base steel sheet (10), in which the insulation coating (20) contains a metal phosphate and an organic resin, an arithmetic mean of a center line average roughness Ra.sub.75 of the insulation coating (20) in a rolling direction of the base steel sheet (10) and a center line average roughness Ra.sub.75 of the insulation coating (20) in a direction perpendicular to the rolling direction is 0.20 to 0.50 ?m, and the amount of nitrogen in the insulation coating (20) is 0.05 to 5.00 mass %.

This non-oriented electrical steel sheet includes a base steel sheet (10); and an insulation coating (20) formed on a surface of the base steel sheet (10), in which the insulation coating (20) contains a metal phosphate and an organic resin, an arithmetic mean of a center line average roughness Ra.sub.75 of the insulation coating (20) in a rolling direction of the base steel sheet (10) and a center line average roughness Ra.sub.75 of the insulation coating (20) in a direction perpendicular to the rolling direction is 0.20 to 0.50 ?m, and the amount of nitrogen in the insulation coating (20) is 0.05 to 5.00 mass %.

The invention relates to a liquid composition characterised in that it contains at least one bisphosphonic compound bearing at least one partially fluorinated, perfluorinated (PF) or perfluorpolyether (PFPE) group, and in that the bisphosphonic compound is dissolved in at least one non-flammable fluorinated solvent.