Abstract: Ultra-high strength galvanized steel strip is produced from martensitic, plain carbon, steel strip which is pre-treated by induction heating rapidly or by fluxing, then hot dip galvanized and tempered, and then cooled to stop further tempering. The resulting galvanized steel strip has a microstructure comprising tempered martensite, a tensile strength substantially greater than 120,000 psi (827 MPa) and a coating weight substantially greater than 30 g/m.sup.2 /side.

Abstract: It is an object to provide a process for manufacturing galvannealed steel sheets having high anti-powdering property as required when they are press formed, and stabilized frictional properties in a coil. Steel sheets are plated in a bath having a low aluminum content, while they have, when entering the bath, a low temperature as defined in relation to the aluminum content of the bath, so that an alloying reaction may be prevented. Then, the sheets are heated for alloying in a high-frequency induction heating furnace so that the sheets leaving the furnace may have a temperature of from over 495.degree. C. to 520.degree. C. to yield galvannealed consisting mainly of a .delta..sub.1 phase. An iron or iron-alloy top coating having an appropriate iron content can be applied onto the plated steel surface to improve its paintability.

Abstract: A corrosion-resistant colored architectural material which is essentially lead free and is not highly reflective. The coating on the material is a two-phase metallic coating comprised of a large weight percentage of zinc and a relatively large weight percentage of tin. The tin-zinc composition provides for both a highly corrosive-resistant coating which protects the surface of the architectural material from oxidation and also produces a gray, earth tone colored which is not highly reflective.

Abstract: A high-strength cold-rolled steel strip or a molten zinc-plated high-strength cold-rolled steel strip which have a low yield strength, containing, by weight, of 0.0005-0.01% C, not more than 0.8% Si, more than 0.5% but not more than 3.0% Mn, 0.01-0.12%: P. 0.0010-0.015% S, 0.01-0.1% Al, 0.0005-0.0060% N, not less than 0.0001% but less than 0.005-0.1% the content of Nb being made to satisfy Nb .gtoreq.93/12 (C-0.0015), or instead of 0.005-0.1% Nb, 0.0005-0.1% Ti and 0.003-0.1% Nb, the content of Nb and the content of Ti being made satisfy, Ti.gtoreq.3.42N, and the balance Fe and incidental impurities is provided. Another steel strip or molten zinc-plated strip is provided that contains 0.2-3.0% Cr but does not require B, and includes both Ti and Nb. The method of producing such is also provided.

Abstract: The invention relates to a substrate for reinforcing elastomeric polymers whereby at least part of the substrate is made of steel, said part being covered by a layer of an alloy consisting of, apart from impurities, between 4.2 and 6.5% weight of aluminum, possibly less than 0.1% of at least one element stimulating the wetting ability of the liquid alloy to the substrate and the balance zinc.

Abstract: A metal wire for reinforcing articles made of elastomeric material, especially vehicle tires. The subject wire has a coating formed by two concentric layers of zinc-nickel or zinc-cobalt alloys, the radially inner layer of which has a zinc content greater than 90% while the radially outer layer has a nickel or cobalt content greater than 50%.

Abstract: A surface-coated steel sheet having improved corrosion resistance and suitable for use as automobile inner and outer panels comprises a steel sheet having on at least one surface thereof a composite coating which comprises the following layers (a) to (d) from the bottom to the top of the coating:(a) a first zinc alloy plating layer with a coating weight of 10-100 g/m.sup.2 which contains at least one of Ni and Co in an amount satisfying the following inequality:0.05.ltoreq.(5.times.Co)+Ni.ltoreq.10 (in weight percent),(b) a second zinc alloy plating layer with a coating weight of 0.05-10 g/m.sup.2 which contains at least one of Ni and Co in an amount satisfying the following inequality:10<(5.times.Co)+Ni.ltoreq.40 (in weight percent),(c) a chromate film layer with a coating weight of 20-300 mg/m.sup.2 as Cr, and(d) an organic coating layer with a thickness of 0.2-5 .mu.m.

Abstract: A zinc or zinc-alloy plated steel sheet having an improved weldability and plating properties, as well as a method for making the same is provided. Even when the substrate steel sheet is the one which is difficult to deposit a zinc or zinc-alloy layer by conventional methods, such as an extra low carbon steel sheet, the present invention enable a reliable production of a galvanized steel sheet suffering from no plating failure or insufficient adhesion as well as a reliable production of a galvannealed steel sheet suffering from no plating failure or streaking of the alloyed layer.The zinc or zinc-alloy plated steel sheet having improved weldability comprises an extra low carbon steel sheet, an iron-carbon plated layer or a carbon-rich layer generated by diffusion of the iron-carbon plated layer on at least one major surface of the extra low carbon steel sheet, and a zinc or zinc-alloy plated layer on the iron-carbon plated layer or the carbon-rich layer.

Abstract: In a hot-dip zinc-coated steel sheet exhibiting excellent press die sliding characteristics and obtained by performing a molten galvanization and then skin pass rolling on a surface of the steel sheet, a galvanized layer has a three-dimensional average surface roughness ranging from 0.7 .mu.m to 1.4 .mu.m, and a skewness (S) of the amplitude probability distribution of the surface roughness, which is defined by the following equation (1), ranging from 0.1 to -0.3:S=.mu..sub.3 /.sigma..sup.3 (1)where.mu..sub.3 : Three-dimensional moment of the amplitude probability density.sigma.: Standard deviation of the amplitude probability density.

Abstract: An Al-Zn-Si base alloy coat including an Al-Zn-Si-Fe alloy layer which has remarkable high corrosion resistance is formed on an article. A ferrous base material is used as the article to provide Fe to the alloy layer. The alloy layer of the present invention consists of 55 to 65 wt % of Al, 25 to 35 wt % of Zn, 5 to 10 wt % of Fe, and 2 to 4 wt % of Si, and also has a cross sectional area of 15 to 90% of the entire cross sectional area of the alloy coat. A process for forming the alloy coat of the present invention comprises the step of dipping the article into a molten bath of Zn to form, on the article, an undercoat which results from a reaction between Fe of the article and Zn in the molten bath, and then dipping the undercoat into an alloy molten bath of Al, Zn and Si to form the alloy coat of the present invention on the undercoat.

Abstract: Organic composite coated steel strips having improved corrosion resistance, weldability and coating adherence are obtained when an organic composite layer is applied to a chromate layer on a zinc or zinc base alloy plated steel substrate. The chromate layer containing up to 70% of Cr.sup.6+ based on the total chromium weight is coated in a weight of 5 to 500 mg/m.sup.2 of Cr. The organic composite layer is formed to a dry weight of 0.2 to 3.0 g/m.sup.2 from a coating composition comprising (A) a silica sol having silica dispersed in an organic solvent with a water content of up to 3.0%, the silica having an organic deposit on its surface in an amount of up to 5.0% of C based on the total silica weight, the silica having an average particle size of 0.05 to 3.0 .mu.m and a specific surface area of 50 to 800 m.sup.2 /g, and (B) an organic resin binder having a number average molecular weight of at least 2,000. The coated strips are suitable for use as automobile bodies by press forming.

Abstract: A zinc-plated metallic material resistant to corrosion at elevated temperatures comprising a metallic material; a plating layer consisting of zinc or zinc alloy containing 70% by weight or more of zinc; and a coating layer on the plating layer comprising 10 to 5,000 mg. of magnesium oxide or hydrated magnesium oxide and 50 to 5,000 mg. of chromium oxide or hydrated chromium oxide per square meter of the coating layer.

Abstract: A steel product having a coating based on a hypereutectic zinc-aluminium alloy made by passing it through a zinc bath containing aluminium and silicon wherein the aluminium content is approximately 55% by weight, the silicon content is 1% to 2% by weight, and the bath further includes strontium in a quantity in the range 0.0001% to 0.2% by weight and at least one other element selected from among vanadium in a quantity in the range of 0.02% to 0.2% by weight and chromium in a quantity in the range of 0.005% to 0.2% by weight. The addition of strontium and chromium and/or vanadium stabilizes the structure of the coating and reduces the formation of acicular precipitates of silicon. The coating has an improved adherence and ductility which permits it to be formed without cracking, while retaining an excellent resistance to corrosion. The resulting crystallization pattern of the coating is also finer and more regular and is independent of the substrate.

Abstract: A thin flexible laminate for overlay application on the pins of a connector or other circuit element, having an electrically insulating substrate, a conductive lamina of apertured pin receiving pads and a separate ground strip adjacent the pads, and an electrically insulating cover lamina, the substrate and cover having apertures aligned with the pad apertures, the cover having second apertures exposing adjacent edges of said pads and ground strip, with an electrical overstress pulse responsive composite material positioned in the second apertures and bridging the pads and the ground strip.

Abstract: Steel plate for automobile bodies and a method for manufacturing the steel plate are disclosed, the steel plate containing 0.02.about.0.03% of P as an alloying element with a total amount of Cu, Ni, Cr, and Mo being more than 0. 01% but less than 0.08 weight % and being electroplated with a Zn alloy.

Abstract: The invention relates to a process for treating an elongated, coated substrate, whereby the treatment comprises the application by cathode sputtering of a material containing at least one component and whereby the composition of this material has been chosen in accordance with the difference between the composition of the coating or the surface of the coating as measured and the desired composition of the coating or the surface of the coating.

Abstract: Steel plate for automobile bodies and a method for manufacturing the steel plate are disclosed, the steel plate containing 0.02.about.0.03% of P as an alloying element with a total amount of Cu, Ni, Cr, and Mo being more than 0.01% but less than 0.08 weight % and being electroplated with a Zn alloy.

Abstract: A brown coated article which exhibits stable color is provided by the composition and structure of a zinc hot-dip galvanizing layer. The zinc hot-dip galvanizing layer consists essentially of from 1 to 15% by weight of Fe and from 0.05 to 1% by weight of Mn, and balance of Zn. A brown Zn-Mn-Fe oxide layer is present on the surface of the zinc hot-dip galvanizing layer.

Abstract: Disclosed are electro-plated steel sheets having a primer coating composed of 5 to 30% by weight of Cr, 0.005 to 5% by weight of cation polymer, with the balance being Zn, with or without a further Zn or Zn-alloy coating formed on the primer coating. The primer coating may contain fine particles of oxides and/or iron-group metals, and may further be applied with a chromate film and/or an organic coating. Also disclosed is the process for producing an electro-plated steel sheet having excellent corrosion resistance and surface brightness, comprising performing electro-plating in an acidic Zn plating bath containing Cr ions and cation polymer, with the ratio of Cr.sup.6+ ions/Cr.sup.3+ ions being not more than 0.1.

Abstract: There is disclosed a conductive and corrosion resistant steel sheet comprising a steel sheet material having an arithmetic average roughness (Ra) of 0.01 to 2.0 .mu.m, preferably, 0.2 to 1.5 .mu.m, and a coating film applied thereon and having a dry thickness of 18 to 110%, preferably 30 to 90%, of said Ra.

Abstract: A galvanized steel sheet is provided which has a tensile strength of not less than 80 kgf/mm.sup.2 and a yield ratio of not more than 60%, and which is applicable to members of an automobile body, particularly those requiring strength.By appropriately controlling the amounts of components, such as C, Mn, Nb, Ti and B, the structure of the steel sheet is formed into a dual-phase structure having a second phase strucutre. The steel sheet is recrystallization-annealed, galvanized while it is maintained at a temperature range near 500.degree. C., and then is cooled. By controlling the rate of cooling the steel sheet, the second phase structure generated is prevented from hardening more than necessary. A galvanized high-strength steel sheet is obtained which has a low yield ratio and excellent stretch-flanging properties.

Abstract: A building low yield ratio hot-dip galvanized cold rolled steel sheet having an improved refractory property, consists essentially of, by weight, 0.1% or less of C, 0.1 to 1.5% of Mn, 0.1% of less of P, 0.06% or less of Al, 0.6 to 2.0% of Cu, and a remainder of Fe and unavoidable impurities and having a 0.6 times or more yield point strength at 600.degree. C. compared to that at normal temperatures. The method of forming the steel sheet comprises the steps of: forming a slab from a steel consisting essentially of, by weight, 0.1% or less of C, 0.1 to 1.5% of Mn, 0.1% or less of P, 0.06% or less of Al, 0.6 to 2.0% of Cu, and a remainder of Fe and unavoidable impurities, immediately or after heating the slab at a temperature of 1200.degree. C. or less, hot rolling the slab at a temperature of 750.degree. C. or more and cold rolling, effecting a continuous hot-dip galvanizing process, heating the rolled slab at a temperature of 700.degree. to 900.degree. C.

Abstract: The improved corrosion-resistant steel plate with an organic coating comprises a steel plate having a zinc or zinc alloy plate layer which is overlaid with a chromate film which in turn is coated with an organic resin paint film. The organic resin coat comprises an epoxy resin which is prepared by reacting with an isocyanate compound and has a dialkanolamine incorporated into its bisphenol A skeleton, and silica. The dialkanolamine combines with a urethane-modified epoxy resin to provide satisfactory curability at low temperatures; at the same time, it combines with the silica to provide a satisfactory film reinforcing effect. The organic coat formed of this composition can be effectively cured at low temperatures and yet it will neither dissolve nor soften upon swelling under the action of the alkali that is generated during cationic electrodeposition at the interface between the electrodeposited film and the organic coat.

Abstract: The improved corrosion-resistant steel plate with an organic coating comprises a steel plate having a zinc or zinc alloy plate layer which is overlaid with a chromate film which in turn is coated with an organic resin paint film. The organic resin coat comprises an epoxy resin having a dialkanolamine incorporated into its bisphenol A skeleton, an amino resin, and silica. The dialkanolamine combines with the amino resin to provide satisfactory curability at low temperatures; at the same time, it combines with the silica to provide a satisfactory film reinforcing effect. The organic coat formed of this composition can be effectively cured at low temperatures and yet it will neither dissolve nor soften upon swelling under the action of the alkali that is generated during cationic electrodeposition at the interface between the electrodeposited film and the organic coat.

Abstract: Galvanic protection of steel is provided by teaching of a technique for determining alloys of compositions useful for the cathodic protection. The technique includes determining the critical cathodic protection potential for steel and the galvanic current and corrosion potential for candidate metal alloy compositions followed by coupling to the steel of one such alloy composition whose determined corrosion potential is lower than the critical corrosion potential for the steel in the corrosive environment in which protection is sought.

Abstract: A precoated steel sheet having improved corrosion resistance and formability is disclosed, which comprises a Zn- or Zn alloy-plated steel sheet having on the plated surface either a colloidal silica-containing chromate undercoat layer and a polyhydroxypolyether resin-based topcoat of 0.3 to 10 .mu.m in thickness in which resin is derived by polycondensation of a dihydric phenol component selected from a mononuclear dihydric phenol, dinuclear dihydric phenol, and a mixture of both, with an epihalohydrin or a non-colloidal material-containing chromate underlayer and an epoxy resin based topcoat containing colloidal silica of a thickness of from 0.3-1.6 .mu.m in thickness. In spite of the absence of zinc powder, the precoated steel sheet can be satisfactorily welded by resistance welding when the thickness of the topcoat layer is not greater than 2.5 .mu.m, and even with such a thin topcoat, the precoated steel sheet retains its improved corrosion resistance and formability.

Abstract: Zn-Mg alloy is plated by vapor deposition on the surface of metals. Since Zn and Mg are vapor-deposited as a vapor mixture of an optional ratio on the surface of metals, plated layers of excellent corrosion resistance, peeling resistance of coating film, formability, etc. can be formed. There is disclosed a method of forming uniform vapor mixtures of Zn and Mg, and vapor-depositing them on the surface of metals as the method forming the vapor-deposited layers.

Abstract: A method of producing a hot-dip galvannealed steel sheet from a very-low-carbon cold-rolled steel sheet containing not less than 0.01 wt % but not more than 0.1 wt % of Ti, by subjecting the cold rolled steel sheet to a process conducted in a continuous hot-dip galvanizing system including a heat treatment, hot-dip galvanizing and a subsequent galvannealing. The method is characterized by the steps of: subjecting the cold-rolled steel sheet to a degreasing and an acid cleaning; subjecting the degreased and acid-cleaned steel sheet to a heat treatment conducted in a reducing gas atmosphere; and cooling the heat-treated steel sheet at a temperature not lower than 380.degree. C. but not higher than the hot-dip galvanizing bath temperature, before the steel sheet is subjected to the hot-dip galvanizing. The very-low-carbon cold- rolled steel sheet contains, besides not less than 0.01 wt % but not more than 0.1 wt % of Ti, not more than 0.005 wt % of C, not less than 0.01 wt % but not more than 0.

Abstract: Uniaxially oriented soft magnetic thin film consists essentially of 1 to 15 atomic percent of Co and/or Ni, and the balance being Fe, and has a crystal structure of a body-centered cubic system, wherein the film is oriented substantially in the [111] direction and the absolute value of the saturation magnetostriction .lambda..sub.f of the film is not more than 5.times.10.sup.-6. The film has low coercivity 1 Oe or less and high magnetic permeability maintaining high saturation magnetic flux density of 18 kG or more. .lambda..sub.f reaches zero and is adjustable. Addition of 0.2 to 20 atomic percent of Ru, Mn, Cr and/or V increases wear resistance. The film is formed by deposition on {111} plane of GaAs substrate, or on c-plane of hexagonal B.sub.8 stracture.

Abstract: Stainless steel sheets are plated with zinc and further phosphated so as to have chromaticness indices of L=45-53, a=0.0-0.4 and b=1.3-4.4. Thus treated stainless steel sheets have sufficient strength, excellent corrosion resistance and a color well harmonizing with other building materials and environment and do not suffer from color change for a prolonged period of time.

Abstract: A first characteristic of the invention is present in forming a chromate film on the surface of a zinc or a zinc alloy plated steel sheet, and a resin composition film at a coating amount of 0.3 to 5.0 g/m.sup.2 on said chromate fim, said resin composition film comprising an organic solvent soluble epoxy resin and hydrophobic silica in a ratio of 80:20 to 50:50 by weight of epoxy resin:hydrophobic resin, said epoxy resin having a glass transition temperature of 293.degree. to 342.degree. K.A second characteristic of the invention is present in forming a chromate film on the surface of a zinc or zinc alloy plated steel sheet, and a resin composition film at a coating amount of 0.3 to 5.0 g/m.sup.2 on said chromate film, and resin composition film comprising an organic solvent soluble epoxy resin having glass transition temperature of 293.degree. to 342.degree. K.

Abstract: This invention provides an organic multicoated steel sheet susceptible to cationic electrodeposition coating which comprises a zinc or zinc alloy plated steel sheet and as a first layer provided on the surface of said plated steel sheet a sparely soluble chromate film of 1-30% in water soluble matter, 0.01-1.0 in Cr.sup.6+ /Cr.sup.3+ ratio and 10-150 mg/m.sup.2 in total chromium application amount on one surface and as a second layer provided said first layer a solid film having a thickness of 0.3-5 .mu.m of a solvent type coating composition having the following composition based on the weight of non-volatile matter:(a) 30-90% of an urethanated epoxy ester resin having a number-average molecular weight of 300-100,000,(b) 5-40% of a hydrophilic polyamide resin having a polymerization degree of 50-1,000(c) 5-40% of a silica particle of 1-100 m.mu. in average particle size and(d) 1-20% of a polyethylene wax having a molecular weight of 1,000-10,000.

Abstract: Zinc-aluminum based alloy containing magnesium and silicon, both present in quantities up to 0.5% by weight, characterized by very good corrosion resistance and suitable for coating steel products, the resulting coatings being extremely durable and highly flexible.

Abstract: An Fe-Mn steel sheet plated with an electrodeposited lower layer of Zn or a Zn alloy and as an upper layer at least 0.5 g/mn.sup.2 of an Fe-Mn alloy with a manganese content of no more than 60% by weight, electrodeposited on the lower layer, has improved corrosion resistance.

Abstract: A high tensile cold rolled steel sheet improved in stretch flanging property, containing 0.03% to 0.15% by weight of C, 0.05% or less by weight of Si, 0.5% to 1.2% by weight of Mn, 0.005% to 0.045% by weight of Nb, and 0.10% or less by weight of Al, the remainder being iron and unavoidable impurities, and the steel sheet having a uniform and fine recrystallized ferrite structure having a mean grain diameter of 20 .mu.m or less and an area fraction of 95% or more having improving ductility and a process for its preparation.

Abstract: A low carbon steel sheet dip-plated with a Zn-Al alloy, which is in a non-recrystallized and rolled state and which comprises, as an element to raise the recrystallization temperature, at least one of Ti: 0.01.about.0.40% by weight, Nb: 0.01.about.0.10% by weight, and B: 0.001.about.0.010% by weight, and a process for the manufacture thereof which comprises carrying out dip-plating at a temperature lower than the recrystallization temperature.

Abstract: A protective coating of iron and steel products is described, wherein an adherent and rough layer of scale is formed, on which is directly deposited a layer of a protective material. The qualities of the layer of scale result from the fact that the product is shaped hot and the speed of its cooling is controlled so that the resultant thickness of scale is less than a threshold of adherence characteristic of the material and of the temperature at the end of shaping. The layer of protective material is obtained by metallization with zinc or an alloy based on zinc. The invention is principally applicable to long iron and steel products, and in particular to reinforcing bars for concrete.

Abstract: A continuous hot-dip coating line, whereby an aluminum-zinc alloy coating, comprising from 25% to 75% aluminum by weight, is applied to a steel strip, includes an induction furnace whereby the coated strip is heated to a treatment temperature within the range of from 165.degree. C. to 275.degree. C., preferably about 200.degree. C. The strip emerging from the furnace is coiled directly at that treatment temperature into close wound coils having a mass of at least 2 tons, and the coils are allowed to cool in still air at the ambient indoor temperature pertaining, at a rate of no more than 40 centigrade degrees per hour, for all but a predetermined number (typically less than four, usually only one) of the outer turns of the coil which are scrapped, to enhance the ductility of the coating on the remainder of the coil. If the treated coated strip is subsequently painted, the paint is cured at a peak metal temperature of less than 240.degree. C.

Abstract: A galvannealed steel sheet having distinguished anti-powdering property and anti-flaking property is disclosed. The steel sheet comprises a matrix steel sheet and a galvannealed coating layer having a coating weight of 45 to 90 g/m.sup.2, composed of 8.about.12 wt. % Fe and 0.05.about.0.35 wt. %, preferably 0.05.about.0.30 wt. % Al, the balance being Zn, provided on at least one side of the matrix steel sheet, the galvannealed coating layer having a .GAMMA. phase with a thickness of not more than 1.3 .mu.m, preferably not more than 1.0 .mu.m in the region at the boundary to the matrix steel sheet, and the surface region of galvannealed coating layer has a structure either (1) .eta. and .zeta. phases do not exist in the surface region of the galvannealed coating layer, or, (2) when at least one of .eta. and .zeta. phases exist therein, the total amount of the at least one of .eta. and .zeta. phases in the galvannealed coating layer is not more than 1.5 g/m.sup.2.

Abstract: The invention concerns aluminum based alloys of the 7000 series with a high Young'3 s modulus (E.gtoreq.74 GPa), high mechanical strength (R.sub.0.2 .gtoreq.530 MPa in the longitudinal direction), good tenacity (KIC, longitudinal direction .gtoreq.20 MPa.sqroot.m ), and good resistance to corrosion under tension (.sigma..gtoreq.250 MPa in the short transverse direction, durability .gtoreq.30 days ASTM standard G 38-73. The alloy according to the invention is of the following composition by weight: from 5.5 to 8.45% of Zr; from 2 to 3.5% Mg; from 0.5 to 2.5% up to 0.5% Fe; up to 0.5% Si; other elements .ltoreq.0.05% each; and up to 0.15% in all with 0.1.ltoreq.Zr.ltoreq.0.5% 0.3.ltoreq.Cr.ltoreq.0.6%; and 0.3.ltoreq.Mn.ltoreq.1.1%. It is preferably worked by the following process steps: a solid body of the composition claimed above is formed by spray deposition; the body is converted to a worked product, at from 300.degree. to 450.degree. C.

Abstract: A non-magnetic substrate used for a magnetic head comprising a pair of non-magnetic substrates, and a magnetic layer structure sandwiched between the pair of non-magnetic substrates. The magnetic layer structure is comprised, of alternately laminated magnetic layers and intermediate insulating layers. The invention discloses for the substrate material a composition expressed by Zn.sub.x M.sub.y Co.sub.2-x-y O.sub.2, with the proviso that M is Mn or Ni, 0.ltoreq.x.ltoreq.0.4, 0.4.ltoreq.y.ltoreq.1.0, 0.8.ltoreq.x+y.ltoreq.1.0, or CO.sub.x Ni.sub.2-x O.sub.2, with the proviso that 0.2.ltoreq.x.ltoreq.1.8, and having a rock-salt structure.

Abstract: Disclosed are a black surface-treated steel sheet, which comprises a steel sheet or plated steel sheet and a electrodeposited composite plating coating formed in a deposition amount of 0.1 to 5 g/m.sup.2 on the surface of the steel sheet or plated steel sheet, the plating coating containing metallic zinc or Zn--Ni alloy and oxides or hydrous oxides and sulfur compound, and a process for the preparation of a black surface-treated steel sheet, which comprises carrying out the electrolysis in an acidic aqueous solution containing Zn.sup.2+ and, as the main components, at least one member selected from the group consisting of Fe.sup.2+, Co.sup.2+ and Ni.sup.2+, and oxidative ion, and a thio compound, by electrolysis a steel sheet or plated steel sheet as the cathode, and water-washing and drying the treated steel sheet.

Abstract: A plated steel sheet is produced by an electroplating in a plating bath of about 350.degree. to 500.degree. C. containing a chloride of Zn, a chloride of Mg and one, two or more of chlorides of Na, K and Li, with a plating current density ranging between about 20 and 350 A/dm.sup.2.The Zn-Mg alloy plated steel sheet superior both in plating adhesion and corrosion resistance has a plating layer formed on at least one surface thereof in an amount of about 10 to 60 g/m.sup.2, and by electroplating in a bath of a fused salts, the plating layer containing about 1 to 35 wt % of Mg, about 0.5 to 25 wt % of mean value of Fe and the balance substantially Zn and incidental inclusions. The Fe content in the plating layer has such a gradient that its concentration is greatest at the interface between the plating layer and the steel sheet and progressively decreases towards the surface of the plating layer opposite to the steel sheet where the Fe content is substantially zero.

Abstract: A galvannealed steel sheet having a superior spot weldability characteristic in which the steel sheet has a base steel sheet cold-rolled from a material containing 0.005 wt % or less of C, 0.005 to 0.05 wt % of Ti, 0.01 to 0.1 wt % of Al, 0.005 to 0.015 wt % of Nb and 0.0002 to 0.002 wt % of B. In the process for making, the hot-dip plating layer applied after the alloying heat treatment has an Fe content of from 9 wt % to 12 wt %.

Abstract: A colored zinc composite-plated steel sheet which comprises a steel sheet or a plated steel sheet, a colored composite-plating film comprising zinc and an oxide of a coloring metal such as nickel, cobalt, iron, chromium, tin or copper and provided on the steel sheet at a coverage of 0.1-5 g/m.sup.2 and a transparent guard coat of 3 .mu.m or less thick provided on the film is obtained by carrying out electrolysis in an acidic aqueous solution containing zinc ion, a coloring metal ion and nitrate ion, nitrite ion, perchlorate ion, chlorate ion, condensed phosphate ion and having a pH of 1-4 using the steel sheet or plated steel sheet as a cathode at a current density of 5-100 A/dm.sup.2 and a current quantity of 20-200 coulomb/dm.sup.2.

Abstract: An electroplated steel sheet having a plurality of coatings, excellent in workability, corrosion resistance and water-resistant paint adhesivity, which comprises:an iron-chromium-zinc alloy coating as a lower layer, having a coating weight of from 0.1 to 40 g/m.sup.2 per side, formed on the surface of a steel sheet, consisting essentially of:iron: from 3 to under 15 wt. %,chromium: from 0.1 to 1 wt. %, andthe balance being zinc and incidental impurities;another iron-chromium-zinc alloy coating as an intermediate layer, having a coating weight of from 20 to 59.9 g/m.sup.2 per side, formed on the iron-chromium-zinc alloy coating as the lower layer, consisting essentially of:iron: from 10 to 40 wt. %,chromium: from over 1 to under 30 wt.

Abstract: Zn-Mg alloy is plated by vapor deposition on the surface of metals. Since Zn and Mg are vapor-deposited as a vapor mixture of an optional ratio on the surface of metals, plated layers of excellent corrosion resistance, peeling resistance of coating film, formability, etc. can be formed. There is disclosed a method of forming uniform vapor mixtures of Zn and Mg, and vapor-depositing them on the surface of metals as the method forming the vapor-deposited layers.

Abstract: Surface treated steel sheets having excellent rust resistance and weldability, suitable for manufacturing various kinds of cans, produced by a process comprising applying 0.2 to 1 g/m.sup.2 of tin coating on a surface of a nickel coated cold rolled steel sheet, applying 0.01 to 0.3 g/m.sup.2 of zinc coating on the tin coating in such an amount that the ratio of the zinc coating amount to the tin coating amount is in a range from 2 to 30% by weight, and heating the coatings to alloy substantially all of the zinc into the tin coating layer with substantially no non-alloyed zinc left on the tin coating.

Abstract: The invention provides a method for producing a coated steel sheet for a can. A film of aluminum, aluminum alloy, titanium or titanium alloy 0.005 to 5 .mu.m thick is plated on one surface of a steel sheet by means of a dry process. A metal film is also plated on the other surface of the steel sheet by means of a dry process.

Abstract: Disclosed is a steel sheet having an organic composite plating layer excellent in press workability, spot weldability, electrodeposition coatability and corrosion resistance which comprises a zinc plated, aluminum plated or zinc base composite alloy steel sheet, a first layer of an insoluble chromate film of 5% or less in the content of water-soluble matter formed on the surface of the steel sheet at a coverage of 10-150 mg/m.sup.2 in terms of chromium content and a second layer of a coating composition having the following composition coated at a thickness of 0.3-5 .mu.