Patent ID: 8613809
Filing Date: 2013-12-24
Classification: C21D,C22C,F16F

Abstract:
1. A high cleanliness spring steel which is a steel containing C: 1.2% (means mass, hereafter the same with respect to each component) or below (not inclusive of 0%): Si: 3.2-4%, Mn: 0.1-2.0%, Al: 0.1-20 ppm, and the balance comprising iron with inevitable impurities; wherein the total number of (1) oxide-based inclusions having 4 or above for L (the large diameter of an inclusion)/D (the short diameter of an inclusion) and D of 25 μm or above and (2) oxide-based inclusions having less than 4 L/D and L of 25 μm or above, in the oxide-based inclusions having an oxygen concentration of 25 mass % or above and a SiO