Abstract: A high-strength spring steel wire is provided which secures excellent hydrogen embrittlement resistance even when the adding amount of alloy elements is suppressed, and has 80 area % or more of tempered martensite and 1,900 MPa or more of the tensile strength, in which a predetermined chemical composition is satisfied, with C and Si satisfying the relation of the expression (1) below, with prior austenite grain size number being No. 10 or more, and with the hydrogen absorption amount being 14.0 ppm or more. 0.73%?[C]+[Si]/8?0.90%??(1) where [C] and [Si] express the content (mass %) of C and Si respectively.

Abstract: It is an object of the present invention to provide a rolled material, which is a material for high strength spring, and also can exhibit excellent corrosion fatigue properties after quenching and tempering even when suppressing the addition amount of an alloying element; and a wire for high strength spring obtained from such a rolled material. The rolled material for high strength spring of the present invention includes, in % by mass: C: 0.39 to 0.65%, Si: 1.5 to 2.5%, Mn: 0.15 to 1.2%, P: exceeding 0% and 0.015% or less, S: exceeding 0% and 0.015% or less, Al: 0.001 to 0.1%, Cu: 0.10 to 0.80%, Ni: 0.10 to 0.80%, and O: exceeding 0% and 0.0010% or less, with the balance being iron and inevitable impurities, wherein the number of oxide inclusions having an average diameter of 25 ?m or more is 30 or less per 100 g of a steel material, and an amount of nondiffusible hydrogen is 0.40 ppm by mass or less.

Abstract: An object of the present invention is to provide a rolled material for high strength spring, which has excellent wire drawability even when suppressing the addition amount of an alloying element, and which can exhibit corrosion fatigue properties after quenching and tempering. The present invention provides a rolled material for high strength spring, including C, Si, Mn, P, S, Al, Cu and Ni, wherein an amount of nondiffusible hydrogen is 0.40 ppm by mass or less, and an area ratio of ferrite expressed as a percentage satisfies an inequality expression (1) below, and a total area ratio of bainite and martensite is 2% or less: Ferrite area ratio<{(0.77?[C])/0.77?[C]/3+0.08}×100??(1) where [name of element] in the above inequality expression (1) means a content expressed in % by mass of each element.

Abstract: A high-strength spring steel wire is provided which secures excellent hydrogen embrittlement resistance even when the adding amount of alloy elements is suppressed, and has 80 area % or more of tempered martensite and 1,900 MPa or more of the tensile strength, in which a predetermined chemical composition is satisfied, with C and Si satisfying the relation of the expression (1) below, with prior austenite grain size number being No. 10 or more, and with the hydrogen absorption amount being 14.0 ppm or more. 0.73%?[C]+[Si]/8?0.90% ??(1) where [C] and [Si] express the content (mass %) of C and Si respectively.

Abstract: A steel wire for spring is provided which exhibits high strength even without adding a large amount of alloy elements, and is for obtaining a cold winding spring having excellent coiling performance and improved hydrogen embrittlement resistance. The steel wire for spring is characterized in that C: 0.40-0.65% (mass %), Si: 1.0-3.0%, Mn: 0.6-2.0%, P: 0.015% or less (exclusive of 0%), S: 0.015% or less (exclusive of 0%), and Al: 0.015 percent by mass or less (excluding 0%) of S, and Al: 0.001-0.10% are satisfied, with the remainder consisting of iron and inevitable impurities, tempered martensite: 70 area % or more and retained austenite: 6-15 area % with respect to the total microstructure, the prior austenite grain size number obtained by a method stipulated in JIS G 0551 is No. 10.0 or more, and the tensile strength is 1,900 MPa or more.