Patent ID: 7717411

Claim:
A high-strength stainless steel spring, which is made of a stainless steel wire, wherein said stainless steel wire has an chemical component containing 0.04 to 0.08% by mass of C, 0.15 to 0.22% by mass N, 0.3 to 2.0% by mass of Si, 0.5 to 3.0% by mass of Mn, 16 to 20% by mass of Cr, 8.0 to 10.5% by mass of Ni, 0.5 to 3.0% by mass of Ma, and the balance of Fe and inevitable impurities, and said spring has a spring index D/d or D/d′ of 2 to 6, wherein “D” represents the average diameter of the coil “d” represents the diameter of the steel wire in the case that cross sections of the stainless steel wire are in a complete round form, and “d′” represents the value obtained by subtracting the average coil diameter from the outer diameter of the coil in the case that the cross sections of the stainless steel wire are in a form other than the complete round form, wherein an atomic percentage ratio of Mo to N (Mo/N) is from 0.6 to 1.3 in the stainless steel wire, and wherein an arithmetical average of Vickers hardnesses of the cross sections of the stainless steel wire is from 400 to 550 after the wire is subjected to coiling and before the spring is annealed, and the arithmetical average of the Vickers hardnesses of the cross sections of the stainless steel wire is from 450 to 650 after the spring is annealed.