Abstract: A cold die steel excellent in the characteristic of suppressing dimensional change, which has a chemical composition in mass %: C: 0.7% or more and less than 1.6%, Si: 0.5 to 3.0%, Mn: 0.1 to 3.0%, P: less than 0.05% including 0%, S: 0.01 to 0.12%, Cr: 7.0 to 13.0%, one or two elements selected from the group consisting of Mo and W: amounts satisfying the formula (Mo+(W/2))=0.5 to 1.7%, V: less than 0.7% including 0, Ni: 0.3 to 1.5%, Cu: 0.1 to 1.0% and Al: 0.1 to 0.7%. Preferably, the die steel satisfies the formula in mass %: Ni/Al=1 to 3.7. It is preferred that the die steel also satisfies the following formula in mass %: (Cr?4.2×C)=5 or less and (Cr?6.3×C)=1.4 or more and that it contains 0.3% or less of Nb.

Abstract: A piston ring material is provided which retains excellent mechanical properties and processability, which are required of piston ring materials, and has wearing resistance and scuffing resistance, which are sliding properties required of piston rings. The piston ring material, which is for use in internal combustion engines, contains, in terms of mass %, 0.3-0.8% carbon, 0.1-3.0% silicon, 0.1-3.0% manganese, 0.01-0.3% sulfur, 0.1-2.0% chromium, and 0.05-2.0% the sum of titanium and/or zirconium, with the remainder being iron and incidental impurities. The titanium and/or zirconium contained in the piston ring material and the sulfur contained therein satisfy the following relationship. [Ti (%)+½Zr (%)]/S (%)?5.0 Preferably, the material may contain one or more members selected from up to 1.0% copper, less than 3.0% molybdenum, up to 1.0% aluminum, and less than 2.0% nickel, in terms of mass %.

Abstract: An alloy to be surface-coated, which can keep excellent hardness of 58HRC or above even when the amount of an alloying element added is reduced or even when the alloy is heated to a temperature of as high as 400 to 500° C.; and sliding members produced by forming a hard film on the surface of the alloy. An alloy to be surface-coated, the surface of which is to be covered with a hard film, which alloy contains by mass C: 0.5 to 1.2%, Si: 2.0% or below, Mn: 1.0% or below, Cr: 5.0 to 14.0%, Mo+1/2 W: 0.5 to 5.0%, and N: more than 0.015 to 0.1% with the balance being Fe and impurities, preferably such an alloy which contains by mass C: 0.6 to 0.85%, Si: 0.1 to 1.5%, Mn: 0.2 to 0.8%, Cr: 7.0 to 11.0%, Mo+1/2 W: 1.0 to 4.0%, and N: 0.04 to 0.08%.

Abstract: A piston ring material that when formed into a piston ring product, maintains excellent properties, and that at the production of piston ring rod, realizes excellent processability and shape stability. There is provided a piston ring material for internal combustion engine comprising, by mass, 0.5 to less than 0.7% C, 1.0% or less Si, 1.0% or less Mn, 12.0 to 16.0% Cr, 3.0% or less Mo and/or W (Mo+½W), 0.02 to 0.14% N and the balance Fe and unavoidable impurities, wherein the relationship of contained C, N and Cr satisfies the formulae: 25?43.22C (%)+42.45N (%)?0.02Cr (%)?40, and 0.15?0.92C (%)+0.67N (%)?0.03Cr (%)?0.30.

Abstract: Provided is a coated-surface sliding part having excellent adhesion of a hard coating, and a method for producing the same part. The coated-surface sliding part is a sliding part wherein a hard coating is formed by physical deposition on the surface of a base material formed from, by mass percent, C 0.5 to 0.8%, Si 0.1 to 1.5%, Mn 0.2 to 1.0%, Cr 8.0 to 13.5%, Mo and/or W 0.5 to 4.0% in terms of (Mo+ 1/2 W), and N 0.01 to 0.1%, with the remainder being Fe and impurities. The physically deposited coating is a titanium metal coating further covered by a diamond-like carbon coating. The method for producing a coated-surface part involves sputtering in order to apply the physically deposited coating, which consists of the titanium metal coating and then the diamond-like carbon coating which forms the surface layer, to the surface of the base material having the aforementioned composition. The base material is preferably subjected to argon gas bombardment prior to application of the physically deposited coating.

Abstract: A piston ring material is provided which retains excellent mechanical properties and processability, which are required of piston ring materials, and has wearing resistance and scuffing resistance, which are sliding properties required of piston rings. The piston ring material, which is for use in internal combustion engines, contains, in terms of mass %, 0.3-0.8% carbon, 0.1-3.0% silicon, 0.1-3.0% manganese, 0.01-0.3% sulfur, 0.1-2.0% chromium, and 0.05-2.0% the sum of titanium and/or zirconium, with the remainder being iron and incidental impurities. The titanium and/or zirconium contained in the piston ring material and the sulfur contained therein satisfy the following relationship. [Ti (%)+½Zr (%)]/S (%)?5.0 Preferably, the material may contain one or more members selected from up to 1.0% copper, less than 3.0% molybdenum, up to 1.0% aluminum, and less than 2.0% nickel, in terms of mass %.

Abstract: An alloy to be surface-coated, which can keep excellent hardness of 58HRC or above even when the amount of an alloying element added is reduced or even when the alloy is heated to a temperature of as high as 400 to 500° C.; and sliding members produced by forming a hard film on the surface of the alloy. An alloy to be surface-coated, the surface of which is to be covered with a hard film, which alloy contains by mass C: 0.5 to 1.2%, Si: 2.0% or below, Mn: 1.0% or below, Cr: 5.0 to 14.0%, Mo+1/2 W: 0.5 to 5.0%, and N: more than 0.015 to 0.1% with the balance being Fe and impurities, preferably such an alloy which contains by mass C: 0.6 to 0.85%, Si: 0.1 to 1.5%, Mn: 0.2 to 0.8%, Cr: 7.0 to 11.0%, Mo+1/2 W: 1.0 to 4.0%, and N: 0.04 to 0.08%.

Abstract: A piston ring material that when formed into a piston ring product, maintains excellent properties, and that at the production of piston ring rod, realizes excellent processability and shape stability. There is provided a piston ring material for internal combustion engine comprising, by mass, 0.5 to less than 0.7% C, 1.0% or less Si, 1.0% or less Mn, 12.0 to 16.0% Cr, 3.0% or less Mo and/or W (Mo+1/2W), 0.02 to 0.14% N and the balance Fe and unavoidable impurities, wherein the relationship of contained C, N and Cr satisfies the formulae: 25?43.22C (%)+42.45N (%)?0.02Cr (%)<40, and 0.15 <0.92C (%)+0.67N (%)?0.03Cr (%)<0.30.

Abstract: A cold die steel excellent in the characteristic of suppressing dimensional change, which has a chemical composition in mass %: C: 0.7% or more and less than 1.6%, Si: 0.5 to 3.0%, Mn: 0.1 to 3.0%, P: less than 0.05% including 0%, S: 0.01 to 0.12%, Cr: 7.0 to 13.0%, one or two elements selected from the group consisting of Mo and W: amounts satisfying the formula (Mo+(W/2))=0.5 to 1.7%, V: less than 0.7% including 0, Ni: 0.3 to 1.5%, Cu: 0.1 to 1.0% and Al: 0.1 to 0.7%. Preferably, the die steel satisfies the formula in mass %: Ni/Al=1 to 3.7. It is preferred that the die steel also satisfies the following formula in mass %: (Cr?4.2×C)=5 or less and (Cr?6.3×C)=1.4 or more and that it contains 0.3% or less of Nb.

Abstract: A cold die steel excellent in the characteristic of suppressing dimensional change, which has a chemical composition in mass %: C: 0.7% or more and less than 1.6%, Si: 0.5 to 3.0%, Mn: 0.1 to 3.0%, P: less than 0.05% including 0%, S: 0.01 to 0.12%, Cr: 7.0 to 13.0%, one or two elements selected from the group consisting of Mo and W: amounts satisfying the formula (Mo+(W/2))=0.5 to 1.7%, V: less than 0.7% including 0, Ni: 0.3 to 1.5%, Cu: 0.1 to 1.0% and Al: 0.1 to 0.7%. Preferably, the die steel satisfies the formula in mass %: Ni/Al=1 to 3.7. It is preferred that the die steel also satisfies the following formula in mass %: (Cr?4.2 ×C)=5 or less and (Cr?6.3×C)=1.4 or more and that it contains 0.3% or less of Nb.

Abstract: A material for use as self-lubricating sliding parts, which consists of a steel containing, by mass, from not less than 0.4% to less than 1.5% of C (carbon), 0.1 to 3.0% of Si, 0.1 to 3.0% of Mn, from inclusive zero to 0.5% of Cr, 0.05 to 3.0% of Ni, 0.3 to 2.0% of Al, 0.3 to 20% in total (Mo+W+V) of at least one element selected from the group consisting of Mo, W (tungsten) and V (vanadium), and 0.05 to 3.0% of Cu, wherein there can be observed graphite particles having an average particle size of not more than 3 ?m in a section of the metal structure of the steel. The steel is also used as piston rings. In the steel, the graphite particles observed in the structural section occupy an area rate of not less than 1% in the overall area of the structural section, and have an average particle size of not more than 3 ?m. The steel may further contain not more than 0.3% of S and/or not more than 0.01% of Ca. The steel is subjected to nitriding treatment for use.

Abstract: There are disclosed a piston ring material and a piston ring both having such superior properties contradictory each other as the sliding property required in a piston ring and the mechanical properties of a steel wire material subjected to a manufacture process. The piston ring material or the piston ring consists essentially, by mass, of not less than 0.3% but less than 0.8% C, 0.1 to 3.0% Si, 0.1 to 3.0% Mn, 0.03 to 0.3% S, 0.3 to 6.0% Cr, preferably 3.0 to 6.0% or 0.3 to 1.0% Cr, 0 to 3.0% Cu, and the balance Fe, and the distribution state of sulfide inclusions with a maximum diameter/minimum size≧3 observed on structure parallel to the outer peripheral surface of the formed piston ring is such that an intersecting angle made between straight lines passing the maximum size of two of the sulfide inclusions is not more than 30 degrees. Further, the area ratio of nonmetallic inclusions occupying the structure is 2.

Abstract: There are disclosed a piston ring material and a piston ring both having such superior properties contradictory each other as the sliding property required in a piston ring and the mechanical properties of a steel wire material subjected to a manufacture process. The piston ring material or the piston ring consists essentially, by mass, of not less than 0.3% but less than 0.8% C, 0.1 to 3.0% Si, 0.1 to 3.0% Mn, 0.03 to 0.3% S, 0.3 to 6.0% Cr, preferably 3.0 to 6.0% or 0.3 to 1.0% Cr, 0 to 3.0% Cu, and the balance Fe, and the distribution state of sulfide inclusions with a maximum diameter/minimum size≧3 observed on structure parallel to the outer peripheral surface of the formed piston ring is such that an intersecting angle made between straight lines passing the maximum size of two of the sulfide inclusions is not more than 30 degrees. Further, the area ratio of nonmetallic inclusions occupying the structure is 2.

Abstract: A target for use in reactive sputtering for forming a film by a reaction with nitrogen, which is a target being composed substantially of titanium and nitrogen and having a nitrogen/titanium atomic ratio, N/Ti, of 0.20 to 0.95, and is used for forming a film whose nitrogen ratio is greater than a ratio of nitrogen to titanium in the target by a reaction with a sputtering gas containing nitrogen, and a method for forming a film, which uses the target.