Abstract: A hexavalent chromium-free surface treating agent for Sn- or Al-based coated steel sheet, comprising a trivalent chromium compound (A), a water-dispersible silica (B), a lubricity imparting component (C) made of one or more waxes of polyolefin wax, fluorine-containing wax and paraffin wax, and water, a mass ratio on the solid content basis of the water-dispersible silica (B) to the lubricity imparting component (C), (B)/(C), being within a range from 5/95 to 95/5.

Abstract: A Sn-based metal-coated steel strip excellent in appearance comprises a Ni-based metal (such as Ni, a Ni—Sn alloy, a Ni—Zn alloy, a Ni—Fe alloy and a Ni—Co alloy) preplating layer and a Sn-based metal (such as a Sn—Zn alloy) coating formed thereon, and is characterized in that a Ni emission intensity line and an Fe emission intensity line obtained by glow discharge spectroscopy of the surface of the coated steel strip satisfy a relationship of the formula: T1?T2 wherein T1 is a sputtering time at the peak of a Ni emission intensity line, and T2 is a sputtering time at the inflection point of an Fe emission intensity line, or a relationship of the formulas: T1?T2, and 1?T1/T2?1.

Abstract: A Sn-based metal-coated steel strip excellent in appearance comprises a Ni-based metal (such as Ni, a Ni-Sn alloy, a Ni-Zn alloy, a Ni-Fe alloy and a Ni-Co alloy) preplating layer and a Sn-based metal (such as a Sn-Zn alloy) coating formed thereon, and is characterized in that a Ni emission intensity line and an Fe emission intensity line obtained by glow discharge spectroscopy of the surface of the coated steel strip satisfy a relationship of the formula: T1≧T2

Abstract: A hexavalent chromium-free surface treating agent for Sn- or Al-based coated steel sheet, comprising a trivalent chromium compound (A), a water-dispersible silica (B), a lubricity imparting component (C) made of one or more waxes of polyolefin wax, fluorine-containing wax and paraffin wax, and water, a mass ratio on the solid content basis of the water-dispersible silica (B) to the lubricity imparting component (C), (B)/(C), being within a range from 5/95 to 95/5.

Abstract: The present invention provides a hot-dip Al-plated steel sheet for fuel tanks excellent in air-tightness after welding and corrosion resistance subsequent to forming. The present invention provides, as concrete means, a hot-dip Al-plated steel sheet comprising a steel sheet comprising up to 0.003% of C, up to 0.03% of Si, up to 0.3% of Mn, up to 0.02% of P, up to 0.006% of N, up to 0.1% of Ti, Ti and Nb in a total amount of at least the atomic equivalent of (C+N) and up to 0.2%, 1 to 30 ppm of B, and the balance Fe and unavoidable impurities, and a plating layer comprising 2 to 13% of Si, and the balance Al and unavoidable impurities on the surface of the steel sheet, the steel sheet showing a total elongation of at least 45% after plating. Alternately, the hot-dip Al-plated steel sheet may have a chromate coating in an amount of 5 to 100 mg/m2 on the surface, and it may also have a resin coating on the top surface. As a result, the Al-plated steel sheet is excellent in elongation after Al plating.

Abstract: A tin-plating or aluminum-plating surface treated steel material with excellent corrosion resistance containing an intermetallic compound composed of one or more Group IIa (alkaline earth metal) elements and one or more Group IVb elements in a tin-based plating layer or aluminum-based plating layer on the surface of a steel material. For a tin-based plating layer, the long diameter of the intermetallic compound massive bodies is 1 82 m or greater and the short diameter/long diameter ratio is at least 0.4. For an aluminum-based plating layer, the long diameter of the intermetallic compound massive bodies is 10 &mgr;m or greater and the short diameter/long diameter ratio is at least 0.4.

Abstract: A coating aluminized steel sheet suitable for fuel tanks, which comprises (a) a steel sheet, (b) an aluminized-plating layer formed on one or both sides of the steel sheet and based on aluminum or an aluminum alloy containing 2-15 wt% silicon, and (c) a coating layer formed on at least one of the aluminizing layers and selected from the group consisting of i) a resin chromate film having a film thickness of 0.1-2 &mgr;m and containing a resin and a chromic acid compound, with the resin/metal chromium weight ratio in the range of 0.

Abstract: The present invention provides a hot-dip Al-plated steel sheet for fuel tanks excellent in air-tightness after welding and corrosion resistance subsequent to forming. The present invention provides, as concrete means, a hot-dip Al-plated steel sheet comprising a steel sheet comprising up to 0.003% of C, up to 0.03% of Si, up to 0.3% of Mn, up to 0.02% of P, up to 0.006% of N, up to 0.1% of Ti, Ti and Nb in a total amount of at least the atomic equivalent of (C+N) and up to 0.2%, 1 to 30 ppm of B, and the balance Fe and unavoidable impurities, and a plating layer comprising 2 to 13% of Si, and the balance Al and unavoidable impurities on the surface of the steel sheet, the steel sheet showing a total elongation of at least 45% after plating. Alternately, the hot-dip Al-plated steel sheet may have a chromate coating in an amount of 5 to 100 mg/m2 on the surface, and it may also have a resin coating on the top surface. As a result, the Al-plated steel sheet is excellent in elongation after Al plating.

Abstract: A metal easy open can lid, and a process for producing the same, wherein the can openability is improved and the occurrence of defects in the resin film at the time of shaping is eliminated whereby repair coating of the inner and outer surfaces are made unnecessary by making the cross-sectional shape of the opening guide groove of the easy open can lid an S-shape are provided, wherein, when forming the opening piece for easy manual opening in the metal lid, the properties of the resin film on the metal sheet, the shape and dimensions of the shoulder portions of the punch and die, the clearance, the residual thickness of the opening guide groove, the degree of the push-back processing, etc. are specified so as to achieve a superior can openability without breakage of the resin film by forming an opening guide groove with an S-shaped cross-section.

Abstract: A chromating liquid for forming a chromate film on a Zn or Zn-alloy plated steel sheet, is prepared by adding and mixing a silane coupling agent in a molar ratio of from 0.05 to 0.3 relative to Cr.sup.6+ contained in an aqueous chromating liquid which contains 1-30 g/l of Cr.sup.6+ and 1-30 g/l of Cr.sup.3+ at a weight ratio of Cr.sup.6+ /Cr.sup.3+ ranging from 0.1 to 2.0; and further contains 1-59 g/l of hydrofluoric acid and 1-59 g/l of phosphoric acid at total of hydrofluoric acid and phosphoric acid ranging from 2 to 60 g/l and at a weight ratio of (fluoride ions+phosphate ions)/Cr.sup.3+ ranging from 0.5 to 3.5. and, further said chromating liquid is applied on a surface of the zinc-based plated steel sheet and is then dried, thereby forming the chromate film having a coating amount of from 10 to 150 mg/m.sup.2 in terms of the chromium.

Abstract: A method for producing a composite steel strip having a high corrosion resistance comprises electroplating a steel strip substrate in an electroplating bath to codeposit a zinc-based metal matrix and corrosion-preventing fine solid particles. The particles comprise a core which may be, for example, chromate, phosphate, aluminum, molybdenum or titanium compounds and a thin coating membrane which may be, for example, SiO.sub.2, Al.sub.2 O.sub.3, ZrO.sub.2, TiO.sub.2 or a resin encapsulating the core. The core material is soluble in the electroplating bath while the coating membrane is substantially insoluble in the electroplating bath. The electroplating bath also contains an agent for promoting the codeposition of the zinc-based metal matrix and the particles, and may optionally include a number of additional fine particles which may be, for example, SiO.sub.2, TiO.sub.2, Cr.sub.2 O.sub.3, Al.sub.2 O.sub.3, ZrO.sub.2, SnO.sub.2, or Sb.sub.2 O.sub.5.

Abstract: A grain-oriented electromagnetic steel sheet has an ultra low watt loss and heat resistant subdivided magnetic domains. The electromagnetic steel sheet has spaced apart regions of plastic strain and an insulating coating disposed thereon. Intruders are thermally intruded into the spaced apart regions of plastic strain causing the subdivided magnetic domains to be heat resistant and maintaining the subdivided magnetic domains after stress relief annealing. Preferred intruders include Sb and Sb containing materials.

Abstract: An electroplated composite steel strip having a high corrosion resistance comprises a steel strip substrate and a corrosion resistant coating layer which comprises at least a base plating layer comprising a zinc-based metal matrix, a number of corrosion-preventing fine solid particles consisting essentially of core fine particles of, for example, chromate, phosphate, aluminum, molybdenum or titanium compounds, and encapsulated by very thin coating membranes consisting of, for example, SiO.sub.2, Al.sub.2 O.sub.3, ZrO.sub.2 or TiO.sub.2, and optionally a number of additional fine particles consisting essentially of, for example, SiO.sub.2, TiO.sub.2, Cr.sub.2 O.sub.3, Al.sub.2 O.sub.3, ZrO.sub.2, SnO.sub.2 or Sb.sub.2 O.sub.5.

Abstract: Method for subdividing the magnetic domains of a grain-oriented electrical steel sheet is improved so that the watt loss can be further lessened and the watt-loss improving effect does not disappear during stress relief annealing. An intrudable means is formed on the finishing-annealed steel sheet on or in the vicinity of strain which promotes the intrusion of an intrudable means. Sb or Sb containing material is a preferred intrudable means and the laser irradiation is a preferred method for imparting the strain and also for attaining the removal of a surface coating.

Abstract: The heat resistant subdivision of magnetic domains of a grain-oriented electrical steel sheet for improving the watt loss characterized by forming intruders therein is improved by pickling the steel sheet prior to the electroplating of the intrudable means. The partly exposed steel sheets are pickled by HNO.sub.3, H.sub.2 SO.sub.4 containing Fe.sup.3+, HCl containing Fe.sup.3+, and/or HBF.sub.4.

Abstract: A plated composite steel strip having a high corrosion resistance comprises a steel strip substrate, a base electroplating layer comprising a Zn or Zn alloy matrix, substantially water-insoluble chromate particles, and additional fine or colloidal particles of SiO.sub.2, TiO.sub.2, Cr.sub.2 O.sub.3, Al.sub.2 O.sub.3, ZrO.sub.2,SnO.sub.2 and/or Sb.sub.2 O.sub.5, and optionally, an additional electroplating layer formed on the base layer and consisting of Zn, Fe, Co, Ni, Mn and/or Cr and/or a surface coating layer containing at least an organic resinous surface layer and formed on the base, or an additional electroplating layer.