STEEL WIRE FOR SPRINGS HAVING EXCELLENT FATIGUE PROPERTIES, AND SPRING.

摘要

　This steel wire for springs: contains specific amounts of C, Si, Mn, Cr, Al, Ca and Ti, with the remainder comprising iron and unavoidable impurities; has oxide inclusions, which are present in a cross section parallel to the longitudinal direction of the wire spring and have minor axes of at least 1 mm, containing specific amounts of CaO, Al2O3, SiO2, MgO, MnO and TiO2. The steel wire for springs satisfies CaO + Al2O3 + SiO2 + MgO + MnO + TiO2 ‰¥ 80%, and the number of oxide inclusions having a minor axis of 2 mm or greater present in the cross section exceeds 0.002/mm2.