Patent ID: 6322747
Filing Date: 2001-11-27
Classification: C21D,C22C

Abstract:
A high-strength spring steel having an Hv of at least 600 and an impact value of at least 40 J/cm.sup.2, comprising 0.40 to 0.70 wt. % carbon, 1.00 to 2.50 wt. % silicon, 0.30 to 0.90 wt. % manganese, 0.50 to 1.50 wt. % nickel, 1.00 to 2.00 wt. % chromium, 0.30 to 0.60 wt. % molybdenum, 0.25 to 0.50 wt. % copper, 0.01 to 0.50 wt. % vanadium, 0.010 to 0.050 wt. % niobium, 0.005 to 0.050 wt. % aluminum, 0.0045 to 0.0100 wt. % nitrogen, 0.005 to 0.050 wt. % titanium, and 0.0005 to 0.0060 wt. % boron, with phosphorus limited to 0.010 wt. % or less, sulfur to 0.010 wt. % or less, and O.sub.T to 0.0015 wt. % or less, and the remainder being composed of iron and unavoidable impurities.