Spring steel wire, spring, method of manufacturing spring steel wire, and method of manufacturing spring

摘要

Steel wire for springs is 0.5 mass% or more and 0.8 mass% or less carbon, 1.0 mass% or more and 2.5 mass% or less silicon, and 0.2 mass% or more and 1.0 mass% or less And manganese of 0.5% by mass or more and 2.5% by mass or less, the balance being composed of iron and unavoidable impurities, and made of steel having a tempered martensitic structure. The hardness of the surface layer region which is a region within 10 μm from the outer peripheral surface is harder than 0 HV and 50 HV or less as compared with the region other than the surface layer region.