Spring steel wire
AssigneeSumitomo Electric Industries, Ltd.
InventorsHiromu IZUMIDA, Tetsuya NAKAJIMA
Life of this patent
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Abstract
A spring steel wire includes a main body made of a steel and having a line shape, and an oxidized layer covering an outer peripheral surface of the main body. The steel constituting the main body contains not less than 0.62 mass % and not more than 0.68 mass % C, not less than 1.6 mass % and not more than 2 mass % Si, not less than 0.2 mass % and not more than 0.5 mass % Mn, not less than 1.7 mass % and not more than 2 mass % Cr, and not less than 0.15 mass % and not more than 0.25 mass % V, with the balance being Fe and unavoidable impurities. A value obtained by dividing a sum of a Si content and a Mn content by a Cr content is not less than 0.9 and not more than 1.4. The steel constituting the main body has a tempered martensite structure.
Claims6
A spring steel wire comprising:
- a main body made of a steel and having a line shape;
- and
- an oxidized layer covering an outer peripheral surface of the main body;
- the steel constituting the main body containing not less than 0.62 mass % and not more than 0.68 mass % C, not less than 1.6 mass % and not more than 2 mass % Si, not less than 0.2 mass % and not more than 0.5 mass % Mn, not less than 1.7 mass % and not more than 2 mass % Cr, and not less than 0.15 mass % and not more than 0.25 mass % V, with the balance being Fe and unavoidable impurities, a value obtained by dividing a sum of a Si content and a Mn content by a Cr content being not less than 0.9 and not more than 1.4,
- the steel constituting the main body having a tempered martensite structure.
A spring steel wire comprising:
- a main body made of a steel and having a line shape;
- and
- an oxidized layer covering an outer peripheral surface of the main body;
- the steel constituting the main body containing not less than 0.62 mass % and not more than 0.68 mass % C, not less than 1.6 mass % and not more than 2 mass % Si, not less than 0.2 mass % and not more than 0.5 mass % Mn, not less than 1.7 mass % and not more than 2 mass % Cr, and not less than 0.15 mass % and not more than 0.25 mass % V, with the balance being Fe and unavoidable impurities, a value obtained by dividing a sum of a Si content and a Mn content by a Cr content being not less than 1 and not more than 1.2,
- the steel constituting the main body having a tempered martensite structure wherein
- the oxidized layer has a thickness of not less than 2 μm and not more than 5 μm,
- the oxidized layer contains Fe3O4 in a percentage of not less than 80 mass %, and
- the spring steel wire has an outer diameter of not less than 0.5 mm and not more than 12 mm.
Dependencies are inferred from the claim text.