Patent ID: 11892048
Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
Field: Materials, metallurgy (Chemistry)
Classification: CPC F  C | IPC C  F

Claim 0:
1. 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 0.5 mass % and not more than 0.7 mass % C, not less than 1 mass % and not more than 2.5 mass % Si, not less than 0.2 mass % and not more than 1 mass % Mn, and not less than 0.5 mass % and not more than 2 mass % Cr, with the balance being Fe and unavoidable impurities,
the steel constituting the main body having a pearlite structure,
the oxidized layer having an average thickness of more than 2 μm and not more than 5 μm,
the oxidized layer containing not less than 60 mass % Fe3O4.