| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To inexpensively provide a spring steel which suppresses the increase of production cost caused by the charge of large quantities of expensive alloy elements such as Ni and Cu, and further, V, Mo or the like, further has high strength and high toughness, and further has excellent delayed fracture resistance. <P>SOLUTION: Disclosed is a high strength spring steel having a componential composition comprising 0.40 to 0.65% C, 1 to 2% Si,≤0.8% Mn,≤0.01% S, 0.05 to 0.60% Mo, 0.3 to 1.5% Cr and 0.0005 to 0.0100% B, and the balance Fe with inevitable impurities, and having a structure in which the fraction of martensite is≥90% and also the grain size of old austenite is≤10μm, and having a tensile strength of≥1,900 MPa and the total elongation of≥10%. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
