Disclosed herein is an aqueous composition having a pH value at 55° C. in the range from 5 to 9, containing at least one different amino organophosphonic acid derivatives of formula (I)

##STR00001##

where residues R independently of each other are CH.sub.2—PO(OR″).sub.2, residues R′ independently of each other are alkylene residues with 2 to 4 carbon atoms, residues R″ independently of each other are H, Na, K, Li or NH.sub.4; and n is an integer from 0 to 4; and at least one copolymer, which is water-soluble or water-dispersible Further disclosed herein are a concentrate to produce such compositions, a pickling method for pickling metallic substrates making use of the compositions, a coating method for coating metallic substrates including the pickling method and a method of using the compositions for pickling metallic substrates.

Disclosed herein is an aqueous composition having a pH value at 55° C. in the range from 5 to 9, containing at least one different amino organophosphonic acid derivatives of formula (I)

##STR00001##

where residues R independently of each other are CH.sub.2—PO(OR″).sub.2, residues R′ independently of each other are alkylene residues with 2 to 4 carbon atoms, residues R″ independently of each other are H, Na, K, Li or NH.sub.4; and n is an integer from 0 to 4; and at least one copolymer, which is water-soluble or water-dispersible Further disclosed herein are a concentrate to produce such compositions, a pickling method for pickling metallic substrates making use of the compositions, a coating method for coating metallic substrates including the pickling method and a method of using the compositions for pickling metallic substrates.

Described herein is an alternative acidic, aqueous composition for effectively phosphating metallic surfaces, which includes, besides zinc ions, manganese ions, phosphate ions and, preferably, nickel ions, at least one accelerator of a formula R.sub.1R.sub.2R.sub.3C—NO.sub.2 where each of the substituents R.sub.1, R.sub.2 and R.sub.3 on the carbon atom is selected, independently of the others, from the group consisting of hydroxymethyl, 1-hydroxyethyl, 2-hydroxyethyl, 1-hydroxypropyl, 2-hydroxypropyl, 3-hydroxypropyl, 1-hydroxy-1-methyl ethyl and 2-hydroxy-1-methylethyl. Also described herein are a method for producing such a composition, an alternative method for phosphating metallic surfaces, and a method of using phosphate coatings produced accordingly.

This grain-oriented electrical steel sheet includes a steel sheet, an insulation coating disposed on the steel sheet, and a spinel present at a part on the steel sheet at an interface between the steel sheet and the insulation coating by being fitted into the insulation coating, in which an amount of the spinel is 5 to 50 mg/m.sup.2 per unit area of a surface of the steel sheet.

This grain-oriented electrical steel sheet includes a steel sheet, an insulation coating disposed on the steel sheet, and a spinel present at a part on the steel sheet at an interface between the steel sheet and the insulation coating by being fitted into the insulation coating, in which an amount of the spinel is 5 to 50 mg/m.sup.2 per unit area of a surface of the steel sheet.

An anti-coking nanomaterial based on a stainless steel surface. In percentage by weight, the nanomaterial comprises: 0 to 3% of carbon, 23% to 38% of oxygen, 38% to 53% of chromium, 10% to 35% of ferrum, 0 to 2% of molybdenum, 0 to 4% of nickel, 3.5 to 5% of silicon, 0 to 1% of calcium, and the balance of impurity elements. Also disclosed are a preparation method for the anti-coking nanomaterial, the anti-coking nanomaterial that is based on a stainless steel surface and that is prepared by using the preparation method, and a stainless steel substrate comprising the anti-coking nanocrystalline material.

An anti-coking nanomaterial based on a stainless steel surface. In percentage by weight, the nanomaterial comprises: 0 to 3% of carbon, 23% to 38% of oxygen, 38% to 53% of chromium, 10% to 35% of ferrum, 0 to 2% of molybdenum, 0 to 4% of nickel, 3.5 to 5% of silicon, 0 to 1% of calcium, and the balance of impurity elements. Also disclosed are a preparation method for the anti-coking nanomaterial, the anti-coking nanomaterial that is based on a stainless steel surface and that is prepared by using the preparation method, and a stainless steel substrate comprising the anti-coking nanocrystalline material.

In one aspect, a spray foam chemical conversion coating includes a non-hexavalent chromium aqueous chemical conversion coating solution, a foaming agent, and a propellant. In another aspect, a method of producing a corrosion-resistant coating includes spraying a foam chemical conversion coating on a surface of a metal substrate, allowing the foam chemical conversion coating to react with the surface, and removing excess foam chemical conversion coating from the surface. The foam chemical conversion coating contains no hexavalent chromium.

In one aspect, a spray foam chemical conversion coating includes a non-hexavalent chromium aqueous chemical conversion coating solution, a foaming agent, and a propellant. In another aspect, a method of producing a corrosion-resistant coating includes spraying a foam chemical conversion coating on a surface of a metal substrate, allowing the foam chemical conversion coating to react with the surface, and removing excess foam chemical conversion coating from the surface. The foam chemical conversion coating contains no hexavalent chromium.

A method for treating and phosphatizing a metal board without using acid includes the following steps: performing a degreasing step to remove grease and dirt from a surface of the metal board with a degreasing agent; performing a blast-peening step by blasting and peening polygon blast-peening granules on the metal board through a centrifugal impeller to remove an oxidized layer; performing a washing step to clean remaining powders from the metal board after the blast-peening step; performing a phosphatizing step to form a protective phosphate coating on the metal board; performing another washing step to wash off remaining phosphatizing agents from the metal board; performing a rustproofing step to apply a rustproofing agent on the metal board; and performing a drying step to dry the metal board.