Patent ID: 8052925
Filing Date: 2011-11-08
Classification: C21C,C21D,C22C

Abstract:
1. A low carbon resulfurized free-machining steel having a high machinability, consisting of: C: 0.02 to 0.15% by mass; Si: more than 0% by mass up to 0.004% by mass; Mn: 1.20 to 1.70% by mass; P: 0.02 to 0.2% by mass; S: 0.40 to 0.48% by mass; Al: more than 0% by mass up to 0.005% by mass; 0: 0.008 to 0.04% by mass; N: 0.005 to 0.025% by mass, wherein the total of at least one element selected from the group consisting of Ti, Cr, Nb, V, Zr, and B is suppressed to the level of up to 0.02% by mass; and a balance of iron and inevitable impurities, wherein the average oxygen concentration in MnS in the steel is at least 0.4% by mass, wherein the content of soluble N is 0.002 to 0.02% by mass, wherein the soluble Si in the steel is up to 35 ppm, and the soluble Al is up to 1 ppm, wherein the average composition of non-metallic inclusions having an area of at least 25 μm