Abstract: A chromium-free agent for treating metallic surface comprising the following (i)-(iv): (i) at least one of (A) a mixture of an aluminum salt and an inorganic oxide particle and (B) an aluminum-containing inorganic oxide particle comprising aluminum, oxygen and at least one element other than these two (ii) a salt of a metal other than aluminum (iii) a phosphorus compound (iv) a resin and/or a precursor thereof provided that when (i) is a mixture of an aluminum salt and an inorganic oxide particle, the equivalent ratio of phosphorus/aluminum is not less than 0.1. The agent for treating metallic surface is applied to the surface of a metal material such as steel plate, plated steel plate, alloy-plated steel plate, alloy plate, silicon steel plate, stainless steel plate, shape steel, pipe, wire material and the like, and dried to form a film superior in corrosion resistance, adhesion to a metal material and adhesion to a paint.

Abstract: A chromium-free agent for treating metallic surface comprising the following (i)-(iv):

Abstract: A chromium-free composition for treating metal surface comprising (a) a hydroxyl group-containing organic resin, (b) a phosphoric acid and (c) at least one of ions and compounds of at least one metal selected from the group consisting of Cu, Co, Fe, Mn, Sn, V, Mg, Ba, Al, Ca, Sr, Nb, Y and Zn, and (d) at least one of colloids (sol) or powders of SiO.sub.2, SnO.sub.2, Fe.sub.2 O.sub.3, Fe.sub.3 O.sub.4, MgO, ZrO.sub.2, Al.sub.2 O.sub.3 and Sb.sub.2 O.sub.5 ; as well as a metal sheet or metal article having thereon (i) a coating film of the chromium-free composition and optionally (ii) a coating film of a coating composition comprising an organic resin and if desired a colloid (sol) or a powder.

Abstract: The present invention comprises an improved organic composite-plated steel plate which is obtained by applying a thermosetting resin to a chromate-coated alloy-plated steel plate and curing this, wherein, various aqueous resin compositions having the form of basic coating film formation components, such as, for example, aqueous vinyl modified epoxy ester resins, or aqueous vinyl modified epoxy ester resin / blocked isocyanate compound-types, or aqueous vinyl modified epoxy ester resin / blocked isocyanate compounds / colloidal silica-types, are used as the thermosetting resin described above.

Abstract: The present invention comprises an improved organic composite-plated steel plate which is obtained by applying a thermosetting resin to a chromate-coated alloy-plated steel plate and curing this, wherein, various aqueous resin compositions having the form of basic coating film formation components, such as, for example, aqueous vinyl modified epoxy ester resins, or aqueous vinyl modified epoxy ester resin/blocked isocyanate compound-types, or aqueous vinyl modified epoxy ester resin/blocked isocyanate compounds/colloidal silica-types, are used as the thermosetting resin described above.

Abstract: Process for manufacturing a galvanized steel sheet, comprising steps of coating a steel sheet with nickel in an amount of from 0.2 to 2 g/m.sup.2, heating the steel sheet thus coated to a temperature within the range of from 420.degree. C. to 500.degree. C. in a non-oxidative atmosphere, and dipping the nickel coated steel sheet into a molten zinc bath containing aluminum at a content of from 0.1 to 1% without contact with air, wherein the steel sheet is dipped into the molten zinc bath within 15 seconds after the temperature of the steel sheet exceeds 350.degree. C. in the heating step.

Abstract: Process for manufacturing a galvanized steel sheet, comprising steps of coating a steel sheet with nickel in an amount of from 0.2 to 2 g/m.sup.2, heating the steel sheet thus coated to a temperature within the range of from 420.degree. C. to 500.degree. C. in a non-oxidative atmosphere, and dipping the nickel coated steel sheet into a molten zinc bath containing aluminum at a content of from 0.1 to 1% without contract with air, wherein the steel sheet is dipped into the molten zinc bath within 15 seconds after the temperature of the steel sheet extends 350.degree. C. in the heating step.

Abstract: A multiple coated composite steel strip having an excellent corrosion (rust) resistance, weldability and paint adhesion, and thus useful for car bodies, comprises a steel strip substrate, a first metal coating layer, a second chlorate coating layer formed by an electrolytic chromate treatment method, containing 40 to 120 mg/m.sup.2 of chromium and having a content of Cr.sub.2 O.sub.3 of 45% by weight or more, and a third resinous coating layer comprising a homopolymer or copolymer of acrylic acid, methacrylic acid, acrylic acid ester or methacrylic acid ester and 15% to 40% of colloidal silica particles having a very small size of 1 to 12 m .mu.m.

Abstract: A cold rolled steel strip having an excellent conversion coating property is produced by a process comprising:anodic electrolytically treating at least one non-plated surface of a cold rolled steel strip to form a layer of oxides thereon, andcathodic electrolytically treating the above-mentioned surface to remove a portion of the oxide layer to an extent that the remaining portion of the oxide layer is in an amount corresponding to a quantity of electricity of from 0.05 to 4.0 millicoulomb/cm.sup.2 which is necessary to completely remove the remaining portion of the oxide layer by means of a cathodic electrolytic treatment in an aqueous solution containing 19.06 g/l of borax and having a pH of 6.4 at a constant current density of 5 microampere/cm.sup.2 and is in the form of a number of separate dots corresponding to a natural reduction time of from 1.0 to 200 seconds.

Abstract: An oxidation inhibitor comprising;(A) 10 to 200 parts by weight of at least one selected from the group consisting ofSilica powderKaolineMagnesia powderMgO-Cr.sub.2 O.sub.3 refractoriesMg-SiO.sub.2 refractories, andMica(B) 10 to 200 parts by weight of silicic anhydride (SiO.sub.2),(C) 10 to 200 parts by weight of at least one selected from the group consisting of Cr, Al, Ti, Nb, Ni and Cu in the powder form,(D) 5 to 50 parts by weight of at least one selected from the group consisting of colloidal silica and alumina sol, and(E) 1 to 20 parts by weight of water-soluble resin,wherein the ratio of the metal powder to the total solid components is within a range defined by the following formula: ##EQU1## (the total solid components is the sum of (A)+(B)+(C)+(solid component of D)+(E)).

Abstract: A method for preventing decarburization of a steel material comprising applying a mixture of SiC powder and metallic Al powder on the steel material, further applying an oxidation inhibitor thereon, and heating thus coated steel material, so as to give 30 to 500 g/m.sup.2 SiC on the steel material. The present method is particularly useful for preventing the lowering in strength of steel materials due to the surfacial decarburization.

Abstract: A scale inhibitor composition comprising Cr.sub.2 O.sub.3, reducing agent, refractory or clay, SiO.sub.2 and water glass, and a method of inhibiting the formation of scale on the surfaces of metal substrates to be heated in high temperature atmosphere by application of a coating of the scale inhibitor composition either on the metal surface, or on a subbing layer of a parting agent previously applied on the metal surfaces are disclosed, wherein improvements are effected particularly in both yield and prevention of surface scars.

Abstract: A process of treating metals with coatings capable, upon heating, of providing and maintaining a controlled atmosphere around the surfaces of said metals which process comprises coating the surfaces of said metals with base coating composition capable, upon heating, of providing a gas, and then with an over-coating composition capable of maintaining the gas around the surfaces of the metals at high temperatures while excluding an environmental oxidizing atmosphere therefrom, and thereafter heating the coated metals in the oxidizing atmosphere.