Abstract: Disclosed is a spring steel for a high corrosion resistant and high strength, which exhibits an excellent drawability without softening heat treatment after hot rolling, and which has a strength of 1900 MPa or more by quenching and tempering and an excellent corrosion resistance. The spring steel contains elements of C, Si, Mn and Cr, and elements of Ni and/or Mo in suitable amounts, the balance being essentially Fe and inevitable impurities, wherein the elements satisfy the following requirement:2.5.ltoreq.(FP).ltoreq.4.52.0.ltoreq.(FP/log D).ltoreq.4.0where D is a diameter (mm) of the rolled material,and FP=(0.23?C!+0.1).times.(0.7?Si!+1).times.(3.5?Mn!+1) .times.(2.2?Cr!+1).times.(0.4?Ni!+1).times.(3?Mo!+1) in which ?element! represents mass % of the element.

Abstract: The present invention provides a spring steel with excellent performance, characterized in that the spring steel is produced by making a spring steel contain an appropriate amount of at least one or more of Ti, Nb, Zr, Ta, and Hf, thereby generating fine inclusions including carbide, nitride, sulfides and/or their complex compounds, to make the inclusions exert the effect of trapping diffusive hydrogen whereby the resistance to hydrogen embrittlement is enhanced, wherein the size and number of the coarse inclusions are regulated, thereby suppressing the decrease of the fatigue life. The spring steel can provide a valve spring or a suspension spring or the like, with enhanced strength and higher stress resistance, together with improved resistance to hydrogen embrittlement and fatigue.

Abstract: Disclosed is a spring steel for a high corrosion resistant and high strength, which exhibits an excellent drawability without softening heat treatment after hot rolling, and which has a strength of 1900 MPa or more by quenching and tempering and an excellent corrosion resistance. The spring steel contains elements of C, Si, Mn and Cr, and elements of Ni and/or Mo in suitable amounts, the balance being essentially Fe and inevitable impurities, wherein the elements satisfy the following requirement:2.5.ltoreq.(FP).ltoreq.4.52.0.ltoreq.(FP/log D).ltoreq.4.0where D is a diameter (mm) of the rolled material, and FP=(0.23[C]+0.1).times.(0.7[Si]+1).times.(3.5[Mn]+1).times.(2.2[Cr]+1).tim es.(0.4[Ni]+1).times.(3[Mo]+1) in which [element] represents mass % of the element.