Tin-containing Coating Patents (Class 205/154)
  • Patent number: 10533260
    Abstract: The chemical treatment steel sheet includes a steel sheet, a mat finished Sn plating layer that is provided as an upper layer of the steel sheet and is formed of a ?-Sn, and a chemical treatment layer that is provided as an upper layer of the Sn plating layer. The Sn plating layer contains the ?-Sn of 0.10 g/m2 to 20.0 g/m2 in terms of an amount of metal Sn. A crystal orientation index of a (100) plane group of the Sn plating layer is higher than crystal orientation indexes of other crystal orientation planes. The chemical treatment layer includes a Zr compound containing Zr of 0.50 mg/m2 to 50.0 mg/m2 in terms of an amount of metal Zr, and a phosphate compound.
    Type: Grant
    Filed: February 8, 2016
    Date of Patent: January 14, 2020
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Yasuto Goto, Takashi Futaba
  • Patent number: 10011913
    Abstract: The invention relates to a substrate with a corrosion resistant coating comprising at least one nickel layer and at least one chromium layer as finish. Between these layers, at least one tin-nickel alloy layer is deposited for suppression of corrosion reactions determined by CASS and Russian mud tests. The invention relates also to a method for producing such substrates with corrosion resistant coating.
    Type: Grant
    Filed: December 23, 2011
    Date of Patent: July 3, 2018
    Assignee: Coventya S.p.A.
    Inventors: Gianluigi Schiavon, Diego Dal Zilio
  • Publication number: 20150072167
    Abstract: A method for the coating of a chromium-free surface of a tin-plated steel sheet with a polymer coating, with the chromium-free tin surface of the tin-plated steel sheet first electrochemically oxidized in a first step and a polymer coating applied on the oxidized tin surface in a second step, and an apparatus for the carrying out of the method. A tinplate coated with a polymer coating made of polyethylene terephathalate (PET) and passivated chromium-free, wherein only one thin tin oxide layer and perhaps an adhesion promoter layer are present between the tin surface of the tinplate and the polymer coating, and the use of such a tinplate for the production of packagings.
    Type: Application
    Filed: September 9, 2014
    Publication date: March 12, 2015
    Inventors: Kathleen STEIN-FECHNER, Tanja LOMMEL, Reiner SAUER, Beate BANNEMANN, Petra DIEDERICH, Benjamin LIEBSCHER
  • Publication number: 20150001089
    Abstract: A method for improving a metal coating on a steel strip or a steel sheet or plate. The coating is melted to a maximum temperature above the melting temperature of the material of the coating by inductive heating performed by at least one induction coil and subsequently cooled to a quenching temperature, below the melting temperature, in a cooling device. In order to improve the corrosion stability of the coating, even in the case of thin coating layers, the coating is kept at a temperature above the melting temperature during a holding time and the holding time is adapted to the maximum temperature and the thickness of the coating by moving at least one of the induction coils with respect to the cooling device, in order to melt the coating completely over its entire thickness to the boundary layer with the steel strip.
    Type: Application
    Filed: January 22, 2013
    Publication date: January 1, 2015
    Inventors: Dirk Matusch, Reiner Sauer, Helmut Oberhoffer, Thomas Rainer, Markus Opper
  • Publication number: 20140102907
    Abstract: A method of manufacturing a tin-plated steel sheet includes forming an Sn-containing plating layer on at least one surface of a steel sheet so that the mass per unit area of Sn is 0.05 to 20 g/m2; forming a first chemical conversion coating by immersing the steel sheet in a first chemical conversion solution containing tetravalent tin ions and phosphate ions or cathodically electrolyzing the steel sheet in the first chemical conversion solution; forming a second chemical conversion coating after forming the first chemical conversion coating without drying the steel sheet by immersing the steel sheet in a second chemical conversion solution containing 5 to 200 g/L of aluminum phosphate monobasic and having a pH of 1.5 to 2.4 or cathodically electrolyzing the steel sheet in the second chemical conversion solution; and drying the steel sheet.
    Type: Application
    Filed: December 18, 2013
    Publication date: April 17, 2014
    Applicant: JFE Steel Corporation
    Inventors: Takeshi Suzuki, Norihiko Nakamura, Hiroki Iwasa
  • Publication number: 20130216714
    Abstract: Disclosed is a manufacturing method for steel sheets for containers that enables reliable, continuous manufacture of steel sheets, with excellent film adhesion qualities, for containers. The manufacturing method for steel sheets for containers is a method in which a film containing Zr is formed on the surface of the steel sheets by immersing, and/or subjecting to electrolytic treatment, the steel sheets in a solution containing Zr ions, F ions, and at least one reaction accelerating component selected from a group including Al ions, boric acid ions, Cu ions, Ca ions, metal Al, or metal Cu.
    Type: Application
    Filed: September 14, 2011
    Publication date: August 22, 2013
    Applicant: JFE STEEL CORPORATION
    Inventors: Takeshi Suzuki, Yuka Miyamoto, Yoichi Tobiyama, Hisato Noro, Masao Inose
  • Publication number: 20130192995
    Abstract: The invention relates to a method for the anti-corrosive pretreatment of tinplate, in which an anti-corrosive primer coating is applied in a single step, said primer coating effectively preventing the shiny metal surface of the pretreated tinplate from turning black when the pretreated tinplate of the invention that is provided with a topcoat is in contact with liquids releasing or containing sulfur compounds and with food containing protein. In the disclosed method, the tinplate is anodically polarized in an electrolyte containing silicates of formula M2O.nSiO2, where M is an alkali metal ion or quaternary ammonium ion and n is a natural number between 0.8 and 7. Tinplate pretreated according to the invention can be used in particular for the production of food-safe packaging such as beverage cans or tin cans.
    Type: Application
    Filed: March 13, 2013
    Publication date: August 1, 2013
    Applicant: HENKEL AG & CO. KGAA
    Inventor: HENKEL AG & CO. KGAA
  • Publication number: 20110104514
    Abstract: A method for producing a tinned steel sheet includes forming an Sn-containing plating layer on at least one surface of a steel sheet such that mass per unit area of Sn is 0.05 to 20 g/m2, immersing the steel sheet in a chemical conversion solution which contains greater than 18 to 200 g/L or less of aluminum phosphate monobasic and which has a pH of 1.5 to 2.4 or cathodically electrolyzing the steel sheet at a current density of 10 A/dm2 or less in the chemical conversion solution, forming a chemical conversion coating in such a manner that the steel sheet is washed with water and then dried, and forming a product of a reaction with a silane coupling agent such that the mass per unit area is 0.10 to 100 mg/m2 in terms of Si.
    Type: Application
    Filed: July 2, 2009
    Publication date: May 5, 2011
    Applicant: JFE STEEL CORPORATION
    Inventors: Takeshi Suzuki, Norihiko Nakamura, Hiroki Iwasa
  • Patent number: 7884044
    Abstract: The present invention relates to an electrocatalytic coating and an electrode having the coating thereon, wherein the coating is a mixed metal oxide coating, preferably platinum group metal oxides with or without valve metal oxides, and containing a transition metal component such as palladium, rhodium or cobalt. The electrocatalytic coating can be used especially as an anode component of an electrolysis cell for the electrolysis of a halogen-containing solution wherein the palladium component reduces the operating potential of the anode and eliminates the necessity of a “break-in” period to obtain the lowest anode potential.
    Type: Grant
    Filed: September 1, 2004
    Date of Patent: February 8, 2011
    Assignee: Eltech Systems Corporation
    Inventors: Dino F. DiFranco, Kenneth L. Hardee
  • Patent number: 7517443
    Abstract: The invention refers to a composition and method of electrolytic tinning in continuous a steel strip or plate with an electrolyte composition comprising the following components (g/l): Tin (in a form of tin sulfamate) 50-90, Sulfamic acid, free 40-100, Sulfates, in a form of SO42-0-15, Nitrogen-bearing block polymer 1-6, said block polymer being a copolymer of propylene oxide and ethylene oxide with molecular weight of 3950 to 6450 and “number of ethylene oxide links-to-number of propylene oxide links” ratio of 1.4-1.2:1.0 at initial buildup of required number of links from propylene oxide followed by oxyethylation.
    Type: Grant
    Filed: March 24, 2005
    Date of Patent: April 14, 2009
    Assignee: Danieli & C. Officine Meccaniche S.p.A.
    Inventors: Vladimir Andreevic Paramonov, Vitalij Polikarpovic Vinogradov, Rafkat Spartakovic Takhautdinov, Angelo Frixione, Michele Turchetto, Joseph Frimpong, Anatoliy Aleksandrovic Karpov, Galina Sergeevna Guljaeva
  • Publication number: 20070295530
    Abstract: An electrical component includes a conductive substrate, a tin layer formed on the substrate, and a conformal coating formed on the tin layer to impede tin whisker growth. The conformal coating includes a polymer matrix, and particles that are dispersed about the matrix. The particles are either significantly harder than the polymer matrix, or are significantly softer than the polymer matrix.
    Type: Application
    Filed: July 25, 2006
    Publication date: December 27, 2007
    Inventors: Merrill M. Jackson, David Humphrey
  • Patent number: 7195796
    Abstract: A process is provided for making a composite work article suitable for fabricating rigid sheet metal can components. A steel sheet having first and second surfaces is pre-treated to enhance reception and retention of a multi-layer polymer coating on the pre-treated first surface. The multi-layer polymer coating is melt extruded on the pre-treated first surface and beyond opposite lateral edges of the work article to establish overhang portions, then solidified. The multi-layer polymeric coating has a tie polymeric layer contacting the pre-treated first surface, and a finish-surface polymeric layer.
    Type: Grant
    Filed: August 9, 2004
    Date of Patent: March 27, 2007
    Assignee: ISG Technologies, Inc
    Inventors: John A. Sinsel, Mark V. Loen, Michael S. Bailey
  • Patent number: 6994919
    Abstract: The invention relates to a brazing sheet product including a core sheet, on at least one side of the core sheet a clad layer of an aluminum alloy including silicon in an amount in the range of 4 to 14% by weight, and further including on at least one outersurface of the clad layer a plated layer of nickel-tin alloy, such that the clad layer and all layers exterior thereto form a metal filler for a brazing operation and have a composition with the proviso that the mol-ratio of Ni:Sn is in the range of 10:(0.5 to 9).
    Type: Grant
    Filed: July 18, 2003
    Date of Patent: February 7, 2006
    Assignees: Corus Aluminium Walzprodukte GmbH, Corus Technology BV
    Inventors: Jacques Hubert Olga Joseph Wijenberg, Adrianus Jacobus Wittebrood, Joop Nicolaas Mooij
  • Patent number: 6884523
    Abstract: An external terminal of an electronic component is provided with a lead base material and a metal thin film coating a surface of the lead base material, and an average value of a crystal size index is not less than 7, which is defined based on dimensions of a crystal particle in a direction perpendicular to the lead base material surface and in a direction parallel thereto, taken on a cut surface of the metal thin film defined by a given plane cutting the metal thin film in a direction perpendicular to the lead base material surface. Such constitution provides an electronic component having an external terminal coated with a metal thin film of a simple structure constituted of Sn or a Sn-based and substantially Pb-free alloy, formed by plating on a surface of a lead base material.
    Type: Grant
    Filed: September 10, 2004
    Date of Patent: April 26, 2005
    Assignee: NEC Electronics Corporation
    Inventor: Kenta Ogawa
  • Patent number: 6773217
    Abstract: Flat-rolled steel strip, free of surface iron oxide, is provided with a corrosion-protection metallic coating on both surfaces, followed by continuous-line polymeric coating operations in which a single surface is pre-treated so as to activate that surface for adhesion of molten extruded thin-film polymeric material for in-line travel. Polymeric materials are formulated to provide maleic-anhydride modified polypropylene, which is melted and pressurized for extrusion as a molten thin-film tie-layer for first contacting that activated surface; and, thin-film intermediate and finish layers are each formulated to contain a selected percentage of polybutylene; which are extruded as molten films in overlaying relationship to said first contacting tie-layer.
    Type: Grant
    Filed: July 30, 2002
    Date of Patent: August 10, 2004
    Assignee: Weirton Steeel Corporation
    Inventors: John A. Sinsel, Mark V. Loen, Michael S. Bailey
  • Patent number: 6319621
    Abstract: To establish a technique of further improving the oxidation resistance of the glossy surface of a copper foil that has a composite layer containing chromium, zinc, and phosphorus on its glossy surface is achieved by a copper foil having excellent oxidation resistance characterized by a composite layer containing chromium, zinc, phosphorus, and nickel formed on the glossy surface of the foil and also to a method of manufacturing the same by electrolysis.
    Type: Grant
    Filed: November 30, 1999
    Date of Patent: November 20, 2001
    Assignee: Nikko Materials Company, Limited
    Inventors: Hideta Arai, Kazuhiko Sakaguchi
  • Patent number: 6308544
    Abstract: The invention relates to a coated metal fastener that is prepared by electrogalvanically coating a metal fastener with a layer of tin and zinc mixed crystals, wherein the tin is from about 50 to about 90% by weight of the mixed crystals layer. The fastener plated with the tin and zinc alloy layer has a number of unexpected properties, including stability at higher temperatures than expected, which is important for retaining the strength of a vehicle joint secured with the fastener during subsequent finishing operations; retention of electrical conductivity, which makes the fastener suitable for use as a grounding member; and resistance to galvanic corrosion when the fastener joins metals of differing electrode potential.
    Type: Grant
    Filed: January 22, 1999
    Date of Patent: October 30, 2001
    Assignee: Emhart Inc.
    Inventors: Walter Kuehnl, Dieter Mauer, Reinhold Opper
  • Patent number: 6280596
    Abstract: Methods and apparatus enabling simultaneous electrolytic tinplating of bottom and top surfaces of continuous-strip flat-rolled steel substrate while moving in the direction of its length, are disclosed. Both surfaces are plated in a first cell of a multi-cell horizontally-oriented tinplating line. The stannous ion plating source and the source of electrical power, for each surface, differ. Tin pellets for an upper surface anode are confined in a solution-permeable material confined, within an electrically-conductive lining. Dissolution of surface iron from the steel strip is substantially eliminated, improving the stannous ion plating solution quality, eliminating requirements for harmful additives, and increasing the variety of electrolytically tinplated continuous-strip steel products and processes.
    Type: Grant
    Filed: October 1, 1999
    Date of Patent: August 28, 2001
    Assignee: Weirton Steel Corporation
    Inventors: Ralph Wilkerson, John A. Sinsel, Tony Georgetti, Eugene J. Chelen, Lowell W. Austin
  • Patent number: 6254979
    Abstract: A low friction, low contact resistance coating for electrical terminal members, especially members made of copper base alloys and low carbon steel alloys and plastics, is formed of a coarse electroplate of tin or silver characterized by grains having an average dimension in the range of about 0.5 to 10 micrometers where such grains carry very small particles of polytetrafluoroethylene or the like having average diameters in the range up to about 0.30 micrometers.
    Type: Grant
    Filed: June 3, 1998
    Date of Patent: July 3, 2001
    Assignee: Delphi Technologies, Inc.
    Inventors: George Albert Drew, Mark S. Ricketts, Bryan A. Gillispie, Yang-Tse Cheng, Robert A. Suchanek
  • Patent number: 6207035
    Abstract: A method for manufacturing a metal composite strip for the production of electrical contact components. A film made of tin or a tin alloy is first applied onto an initial material made of an electrically conductive base material. A film of silver is then deposited thereonto. Copper or a copper alloy is preferably used as the base material. The tin film can be applied in the molten state, and the silver film by electroplating. Furthermore, both the tin film and the silver film can be deposited by electroplating. A further alternative provides for manufacturing the tin film in the molten state and the silver film by cathodic sputtering. The diffusion operations which occur in the coating result in a homogeneous film of a tin-silver alloy. This formation can be assisted by way of a heat treatment of the composite strip.
    Type: Grant
    Filed: November 20, 1998
    Date of Patent: March 27, 2001
    Assignee: Stolberger Metallwerke GmbH & Co. KG
    Inventors: Udo Adler, Klaus Schleicher
  • Patent number: 6174426
    Abstract: A method is provided for enhancing the adhesion of organic polymer coatings to electrolytically passivated (CDC) tin-plated steel strip. The method includes applying a solution comprising 0.1 to 7 percent of an adhesion promoter to the electrolytically tin-plated strip during the processing of the strip on an electrolytic tin-plating line. The adhesion promoter may be at least one selected from the group consisting of: where n is within a range of from 4 to 99; (b) C16H33+N(CH3) 3 M where M is member of the halogen group; and (c) Rn—Si—(X)4−n where R is a non-hydrolyzable organic radical selected from the group consisting of glycol, epoxy, amine, diamine or mercapto groups, and mixtures thereof, containing from 3 to 10 carbon atoms; the number n is an integer from 1 to 3; and X is a hydrolyzable group selected from the group consisting of Cl—, OCH3, OCH2CH5, OOCCH3, OCH2OCH3, amine, diamine, triamine, acyloxy and alkoxysilanes, and mixtures thereof.
    Type: Grant
    Filed: August 12, 1999
    Date of Patent: January 16, 2001
    Assignee: USX Corporation
    Inventor: Gabriel Jeminiwa Osanaiye
  • Patent number: 5628893
    Abstract: A composition of matter for electrolytically depositing a tin layer on an iron containing-substrate is disclosed comprising an acidic aqueous mixture of:(a) a stannous tin halide; and(b) a salt having(1) an alkaline cation, and(2) an oxygen-containing inorganic acid anion reducible to a lower oxidation state.The salt is selected to minimize oxidation of Sn (II) to Sn (IV). An electrolytic cell for electrolytically depositing a tin layer on an iron-containing substrate is also disclosed, where the cell has an electrolyte comprising the foregoing composition. The overall cell potential of the cell is decreased, and the free energy increased, compared to an electrolytic cell without the salt. A process is disclosed for depositing a tin layer on an iron containing substrate comprising electrolytically coating the substrate with the composition, or coating the substrate employing the foregoing electrolytic cell. A product made by any of the foregoing processes is also described.
    Type: Grant
    Filed: November 24, 1995
    Date of Patent: May 13, 1997
    Assignee: Atotech USA, Inc.
    Inventor: Vincent C. Opaskar
  • Patent number: 5433839
    Abstract: This sheet metal comprises a substrate (12) made of stainless steel containing more than 16% of chromium in its weight composition, coated with a metal layer (16) containing chiefly tin. Between the metal layer (16) and the substrate (12) the sheet metal comprises a layer (14) of an intermetallic compound containing at least iron, chromium and tin. To manufacture this sheet metal, a layer (16) of metallic coating containing chiefly tin is deposited by an electrolytic route on a sheet (12) made of stainless steel. The coated sheet metal is heated to a temperature above the melting temperature of the coating layer (16) to permit the formation of the intermetallic compound. The heating is maintained for a sufficient period for the surface of the coating layer (16) to have a matt appearance.
    Type: Grant
    Filed: June 11, 1993
    Date of Patent: July 18, 1995
    Assignee: Ugine S.A.
    Inventors: Pascal Amelot, Jean-Claude Bavay
  • Patent number: 5427677
    Abstract: An improved process for reflowing tinplate by treating a matte finish of tinplate with a flux, and reflowing the fluxed matte tinplate to produce bright tinplate, wherein the flux is a naphthalenesulfonic compound, preferably having the a naphthalene ring which is substituted with at least one --SO.sub.3 M group where M is hydrogen, an alkali metal or an alkaline earth metal and is optionally substituted with at least one hydroxy group. The flux is preferably applied to the matte tinplate in an aqueous solution which may contain an acid. The most preferred fluxes are 2-naphthol-6,8-disulfonic acid, 1-naphthol-3,6-disulfonic acid, and dipotassium 2-naphthol-6,8-disulfonate.
    Type: Grant
    Filed: February 18, 1994
    Date of Patent: June 27, 1995
    Assignee: LeaRonal, Inc.
    Inventor: Claudia Mosher
  • Patent number: 5346607
    Abstract: Stannous electrolytic tinplating baths utilized in flat-rolled steel tinplating operations contain non-filterable lead in solution at undesirable levels because of the lead content of commercially available tin anode materials. As taught herein, lead in the electrolyte is controllably incapacitated for deposition with the tin by chemical treatment of the bath which establishes, in solid phase, an insoluble bivalent metal compound having an affinity for lead which is adsorbed. In a preferred halogen-system embodiment, calcium fluoride presents an extended surface area for adhesion of lead and not only incapacitates lead in the bath for deposition purposes but also enables separation of such adsorbed lead from the plating bath as part of sludge removal.
    Type: Grant
    Filed: September 30, 1992
    Date of Patent: September 13, 1994
    Assignee: Weirton Steel Corporation
    Inventors: John L. Swanson, Lowell W. Austin
  • Patent number: 5344550
    Abstract: A surface-treated steel sheet is provided, at a low cost, which has high weldability and is useful for a material of containers of foods and beverages. The surface treatment is conducted by applying flattened granular tin coating deposits having a specified diameter and high adhesion on a steel sheet surface at a specified plated area ratio, and applying thereon a metallic chromium coating and a chromium hydrate oxide coating.In the surface treatment, firstly, the surface of a steel sheet is subjected to tin-plating in an acidic tin plating bath containing a conventionally used brightener in an amount of from 0,001 to 0.05 g/l so as to form flattened granular tin coating deposits having a diameter of 0.4-2.4 .mu. at a plated area ratio of 5 to 30% and to improve the adhesion to the steel sheet and decrease falling-off of the granular tin coating deposits until completion of chrome-plating, thereby the variation of the amount of tin coating being decreased.
    Type: Grant
    Filed: June 8, 1993
    Date of Patent: September 6, 1994
    Assignee: Nippon Steel Corporation
    Inventors: Yoshihiro Kaneda, Ryoichi Yoshihara, Ryousuke Wake
  • Patent number: 5320919
    Abstract: A copper foil for an inner layer circuit of a multi-layered printed circuit board, which comprises a black metal plated layer formed on at least the rough surface which becomes a surface of an inner layer circuit of a copper foil having both sides roughened in advance, in order to enhance the bonding strength to a prepreg, make it safe from haloing and facilitate optical checking of the copper foil.
    Type: Grant
    Filed: May 28, 1991
    Date of Patent: June 14, 1994
    Assignees: Sumitomo Bakelite Company Limited, Circuit Foil Japan Co., Ltd.
    Inventors: Keiji Azuma, Kimikazu Katoh, Ryoichi Oguro, Takashi Inada
  • Patent number: 5312539
    Abstract: A method for plating tin onto the surface of steel strip in an acidic electrolyte bath utilizing insoluble anodes is disclosed. Free acid in the bath is extracted from the bath and concentrated. Tin is dissolved in the concentrated extract and the extract is returned to the bath to replenish the tin in the bath.
    Type: Grant
    Filed: June 15, 1993
    Date of Patent: May 17, 1994
    Assignee: LeaRonal Inc.
    Inventor: Donald Thomson
  • Patent number: 5298149
    Abstract: A copolyester film was laminated onto a steel sheet, this sheet having double layers consisting of a lower layer of metallic chromium and an upper layer of hydrated chromium oxide on a tin plated steel sheet in which 5 to 40% of the surface of the steel sheet is covered with plated tin and the remainder of the steel surface is exposed and the space between plated tin particles is 0.5 to 50 .mu.m, and a method for production of this copolyester resin film laminated steel sheet which comprises: (a) electroplating with tin under restricted conditions, (b) formation of said double layer on the plated tin and exposed steel surface and (c) lamination of the copolyester resin film at a temperature above the melting temperature of tin.
    Type: Grant
    Filed: February 17, 1993
    Date of Patent: March 29, 1994
    Assignee: Toyo Kohan Co., Ltd.
    Inventors: Hiroaki Kawamura, Masatoki Ishida, Atsuo Tanaka, Terunori Fujimoto, Tsuneo Inui, Yoshikazu Kondo
  • Patent number: 5275716
    Abstract: A method for manufacturing a tin-electroplated cold-rolled steel strip, which comprises the steps of: continuously annealing a degreased cold-rolled steel strip; then, subjecting, following the continuous annealing treatment, the continuously annealed cold-rolled steel strip to a continuous tin-electroplating treatment in a tin-electroplating bath to form, on at least one surface of the cold-rolled steel strip, a tin-electroplating layer having a plating weight within a range of from 0.1 to 2.8 g/m.sup.2 per surface of the cold-rolled steel strip; and then, temper-rolling, following the continuous tin-electroplating treatment, the cold-rolled steel strip having the tin-electroplating layer on at least one surface thereof, at a reduction ratio within a range of from 1 to 5%.
    Type: Grant
    Filed: March 11, 1993
    Date of Patent: January 4, 1994
    Assignee: NKK Corporation
    Inventors: Katsumi Kojima, Mikiyuki Ichiba, Hiroki Iwasa, Toyofumi Watanabe
  • Patent number: 5248405
    Abstract: A surface-treated steel sheet is provided, at a low cost, which has high weldability and is useful for a material of containers of foods and beverages. The surface treatment is conducted by applying flattened granular tin coating deposits having a specified diameter and high adhesion on a steel sheet surface at a specified plated area ratio, and applying thereon a metallic chromium coating and a chromium hydrate oxide coating.In the surface treatment, firstly, the surface of a steel sheet is subjected to tin-plating in an acidic tin plating bath containing a conventionally used brightener in an amount of from 0.001 to 0.05 g/1 so as to form flattened granular tin coating deposits having a diameter of 0.4-2.4 .mu. at a plated area ratio of 5 to 30% and to improve the adhesion to the steel sheet and decrease falling-off of the granular tin coating deposits until completion of chrome-plating, thereby the variation of the amount of tin coating being decreased.
    Type: Grant
    Filed: January 21, 1992
    Date of Patent: September 28, 1993
    Assignee: Nippon Steel Corporation
    Inventors: Yoshihiro Kaneda, Ryoichi Yoshihara, Ryousuke Wake