Steel wire for heatproof spring, production mannered null mass of heatproof spring and

摘要

PROBLEM TO BE SOLVED: To provide a steel wire for a heat resistant spring having high strength, and excellent in high temperature tensile strength and high temperature settling resistance required for a spring material in the high temperature range of 350 to 500°C, particularly, at about 400°C.;SOLUTION: The steel wire for a heat resistant spring comprises, by mass, 0.01 to 0.08% C, 0.18 to 0.25% N, 0.7 to 2.0% Si, 0.5 to 4.0% Mn, 16 to 20% Cr, 8.0 to 10.5% Ni, 0.5 to 3.0% Mo and 0.2 to 2.0% Co, and the balance Fe with inevitable impurities. In the steel wire, tensile strength is 1,300 to 2,000 N/mm², the maximum crystal grain size of a γ phase (austenite) in the cross section is 12 μm, and the cross-sectional area is 5.0 to 20 mm² before low temperature annealing.;COPYRIGHT: (C)2004,JPO&NCIPI