To meet the demand for more power and less fuel consumption in automotive engines, higher-strength valve springs are widely used today. However, as is well known, an increase in steel wire tensile strength often leads to shorter fatigue life unless the sensitivity to nonmetallic inclusions and their size are restricted. A study of optimum chemical compositions for higher ductility and strength and nonmetallic inclusion controlling techniques has made it possible to manufacture a valve spring steel with excellent fatigue life at a higher stress level.
展开▼
