Abstract: A high-strength steel excellent in hydrogen embrittlement resistance is provided. The high-strength steel of the present invention excellent in hydrogen embrittlement resistance has a tensile strength of 1800 N/mm2 or above, contains 0.3 to 0.7% (percent by mass) C, 0.95 to 5.0% Cr, not higher than 0.6% and higher than 0% Mn, and 0.7 to 2.5% Si, and contains at least one of Mg, Ca, Sr, Ba, Li, Na and K so as to meet the following conditions: (1) the upper limits of the Mg, the Ca, the Sr, the Ba, the Li, the Na and the K content are 0.05%, and (2) the Mg, the Ca, the Sr, the Ba, the Li, the Na and the K content meet Expression (1): Cr + Mn 4 ? 1000 × [ Ca + Mg + Sr + Ba 2 + Li + Na + K 8 ] .

Abstract: A spring steel having a high strength of 1900 MPa or more and superior in the brittle fracture resistance, as well as a method for manufacturing the same, are provided. The high strength spring steel comprises, as basic components in mass %, C: 0.4-0.6%, Si: 1.4-3.0%, Mn: 0.1-1.0%, Cr: 0.2-2.5%, P: 0.025% or less, S: 0.025% or less, N: 0.006% or less, Al: 0.1% or less, and O: 0.003% or less, the amount of solute C being 0.15% or less, the amount of Cr contained as a Cr-containing precipitate being 0.10% or less, and a TS value represented by the following equation being 24.8% or more, and in point of structure, the pre-austenite grain diameter being 10 ?m or smaller, wherein TS=28.5*[C]+4.9*[Si]+0.5*[Mn]+2.5*[Cr]+1.7*[V]+3.7*[Mo] where [X] stands for mass % of element X.

Abstract: Disclosed are an aluminum alloy material and a plate heat exchanger using the aluminum alloy material, both of which have superior corrosion resistance. Specifically, the aluminum alloy material includes an aluminum alloy base material having an anodic oxide layer with an average thickness of 1 to 20 ?m as its surface layer, an organic phosphonic acid primer coating arranged on the surface of the aluminum alloy base material, and a fluorocarbon resin coating arranged on the surface of the organic phosphonic acid primer coating and having an average thickness of to 100 ?m after drying.

Abstract: Disclosed is a steel sheet for dissimilar materials weldbonding to an aluminum material, the steel sheet containing, in mass, C: 0.02 to 0.3%, Si: 0.2 to 5.0%, Mn: 0.2 to 2.0%, and Al: 0.002 to 0.1%, further one or more of Ti: 0.005 to 0.10%, Nb: 0.005 to 0.10%, Cr: 0.05 to 1.0%, and Mo: 0.01 to 1.0%, and the balance consisting of Fe and unavoidable impurities. In the steel sheet, (i) the proportion of the oxide containing Mn and Si by 1 at.

Abstract: An aluminium alloy material having an excellent sea water corrosion resistance comprises an aluminium alloy substrate whose ten-points average surface roughness Rz, which is the average of five greatest peak-to-valley separations on the surface, is controlled at 0.3 um or over, an organic phosphonic primer film formed on a surface of the aluminium alloy substrate, and a fluorine resin paint film formed on the primer film and having a dry average thickness of 1 to 100 ?m. A plate heat exchanger having an excellent sea water corrosion resistance is also provided wherein the aluminium alloy material is used as a heat transfer unit using sea water as cooling water.

Abstract: A high-strength steel excellent in hydrogen embrittlement resistance is provided. The high-strength steel of the present invention excellent in hydrogen embrittlement resistance has a tensile strength of 1800 N/mm2 or above, contains 0.3 to 0.7% (percent by mass) C, 0.95 to 5.0% Cr, not higher than 0.6% and higher than 0% Mn, and 0.7 to 2.5% Si, and contains at least one of Mg, Ca, Sr, Ba, Li, Na and K so as to meet the following conditions: (1) the upper limits of the Mg, the Ca, the Sr, the Ba, the Li, the Na and the K content are 0.

Abstract: To provide a joint product of a steel product and an aluminum material, and a spot welding method for the joint product, ensuring that spot welding with high bonding strength can be performed. In one embodiment, a steel product 1 having a sheet thickness t1 of 0.3 to 3.0 mm and an aluminum material 2 having a sheet thickness t2 of 0.5 to 4.0 mm are joined together by spot welding to form a joint product of a steel product and an aluminum produce. In this joint product, the nugget area in the joint part is from 20×t20.5 to 100×t20.5 mm2, the area of a portion where the thickness of the interface reaction layer is from 0.5 to 3 ?m is 10×t20.5 mm2 or more, and the difference between the interface reaction layer thickness at the joint part center and the interface reaction layer thickness at a point distant from the joint part center by a distance of one-fourth of the joint diameter Dc is 5 ?m or less.

Abstract: To provide a steel-aluminum welded material and a spot welding method therefor having high weld strength. The steel-aluminum welded material 3 includes a steel material 1 and an aluminum material 2 having predetermined widths. The area of a nugget 5 of a spot-welded part is determined as a function of the thickness of the aluminum material 2, and the area of a part of the nugget 5 corresponding to a part having a thickness in a range between 0.5 and 10 ?m of an interface reaction layer 6 is defined as a function of the thickness of the aluminum material 2.

Abstract: Disclosed is a member which is superior in anti-fungus property and anti-alga property, and is coated with a surface treatment coating comprising at least a layer having anti-fungus property and/or anti-alga property laminated between a topmost surface functional layer and a base, wherein the layer having anti-fungus property and/or anti-alga property comprises 80% or more of Ni, 0.1 to 10% of P, and 0.0001 to 1% of hydrogen, holes reaching the surface of the layer having anti-fungus property and/or anti-alga property are present in the topmost surface functional layer so as to penetrate the topmost surface functional layer, the opening area ratio thereof to the total area when the topmost surface functional layer is viewed in plan being from 0.001 to 10%, or the elution amount of Ni is from 0.1 to 50 ?g/cm2/week when the member is immersed in still water at 30° C.

Abstract: A titanium alloy having excellent high-temperature oxidation and corrosion resistance is disclosed which comprises, by mass, Al: 0.30–1.50%, and Si: 0.10–1.0%. Preferably, amass ratio Si/Al is not less than 1/3. More preferably, the titanium alloy further comprises Nb: 0.1–0.5% by mass. The titanium alloy is useful as an exhaust system material for a vehicle or a motorbike, which enhances corrosion and high-temperature oxidation resistance, while utilizing inherent lightness and corrosion resistance of an original titanium alloy without impairing economy and workability.

Abstract: Disclosed is a steel sheet for dissimilar materials weldbonding to an aluminum material, the steel sheet containing, in mass, C: 0.02 to 0.3%, Si: 0.2 to 5.0%, Mn: 0.2 to 2.0%, and Al: 0.002 to 0.1%, further one or more of Ti: 0.005 to 0.10%, Nb: 0.005 to 0.10%, Cr: 0.05 to 1.0%, and Mo: 0.01 to 1.0%, and the balance consisting of Fe and unavoidable impurities. In the steel sheet, (i) the proportion of the oxide containing Mn and Si by 1 at.

Abstract: A method for manufacturing a dissimilar metal joint member having an excellent corrosion resistance is provided. The method comprises immersing a member having an iron material and Al or an Al alloy material jointed together in a solution containing fluoro complex ions and zinc ions to cause metallic zinc to be deposited in the vicinity of a jointed portion.

Abstract: (1) A titanium material composed of a substrate of pure titanium or titanium alloy and an aluminum-containing layer formed thereon having a thickness no smaller than 1 ?m and containing no less than 90 mass % aluminum or aluminum plus silicon. (2) A titanium material composed of a substrate of pure titanium or titanium alloy and an aluminum-containing layer formed thereon having a thickness no smaller than 1 ?m and containing no less than 90 mass % aluminum or aluminum plus silicon, with a layer of Al—Ti intermetallic compound interposed between them. (3) A titanium material as defined in (1) wherein the substrate contains 0.5-10 mass % aluminum. (4) A titanium material as defined in (1) wherein that surface of the substrate with which the aluminum-containing layer is in contact contains 20-50 atomic % nitrogen. (5) A titanium material as defined in (1) wherein a layer of aluminum nitride is formed in the interface between the substrate and the aluminum-containing layer.

Abstract: A titanium alloy having excellent high-temperature oxidation and corrosion resistance is disclosed which comprises, by mass, Al: 0.30-1.50%, and Si: 0.10-1.0%. Preferably, amass ratio Si/Al is not less than ?. More preferably, the titanium alloy further comprises Nb: 0.1-0.5% by mass. The titanium alloy is useful as an exhaust system material for a vehicle or a motorbike, which enhances corrosion and high-temperature oxidation resistance, while utilizing inherent lightness and corrosion resistance of an original titanium alloy without impairing economy and workability.

Abstract: (1) A titanium material composed of a substrate of pure titanium or titanium alloy and an aluminum-containing layer formed thereon having a thickness no smaller than 1 &mgr;m and containing no less than 90 mass % aluminum or aluminum plus silicon. (2) A titanium material composed of a substrate of pure titanium or titanium alloy and an aluminum-containing layer formed thereon having a thickness no smaller than 1 &mgr;m and containing no less than 90 mass % aluminum or aluminum plus silicon, with a layer of Al—Ti intermetallic compound interposed between them. (3) A titanium material as defined in (1) wherein the substrate contains 0.5-10 mass % aluminum. (4) A titanium material as defined in (1) wherein that surface of the substrate with which the aluminum-containing layer is in contact contains 20-50 atomic % nitrogen. (5) A titanium material as defined in (1) wherein a layer of aluminum nitride is formed in the interface between the substrate and the aluminum-containing layer.

Abstract: Disclosed is a member which is superior in anti-fungus property and anti-alga property, and is coated with a surface treatment coating comprising at least a layer having anti-fungus property and/or anti-alga property laminated between a topmost surface functional layer and a base, wherein the layer having anti-fungus property and/or anti-alga property comprises 80% or more of Ni, 0.1 to 10% of P, and 0.0001 to 1% of hydrogen, holes reaching the surface of the layer having anti-fungus property and/or anti-alga property are present in the topmost surface functional layer so as to penetrate the topmost surface functional layer, the opening area ratio thereof to the total area when the topmost surface functional layer is viewed in plan being from 0.001 to 10%, or the elution amount of Ni is from 0.1 to 50 &mgr;g/cm2/week when the member is immersed in still water at 30° C.

Abstract: A copper alloy comprising 0.1-7.3% of titanium and optionally comprising one or more of zinc, silicon and silver in amounts of 0.001-10%, 0.001-3% and 0.001-1%, respectively, wherein its surface layer contains an oxide containing titanium. This copper alloy exhibits sterilizing effect based on copper and antibacterial effect based on optical catalyst function resulting from the oxide which contains titanium dispersed in the surface layer. The oxide containing titanium can be produced by heating the copper alloy which has the above-mentioned composition and is produced in the usual manner to 200-800° C. to oxidize titanium preferentially. In the case that zinc and silicon are contained, these elements are also preferentially oxidized by the heating, so as to produce oxides. Thus, zinc exhibits antibacterial effect and sterilizing effect. Silicon exhibits hydrophilicity. Silver exhibits sterilizing effect.

Abstract: An Mg based article excellent in plating adhesion which is produced with an Mg alloy base material regardless of its kind by forming a Zn layer of an average thickness of 0.60 .mu.m or more, or a Zn deposition of 0.43 mg/cm.sup.2 or more formed on the Mg alloy base material and a method of producing the article with good efficiency are provided.