简介 |
PROBLEM TO BE SOLVED : To provide a method which is capable of continuous casting of low-carbon sulfur-based free cutting steel without causing an internal crack or a surface crack.
SOLUTION : The continuous casting method is used for casting a molten low-carbon sulfur-based free cutting steel which contains 0.05-0.19% C , 1.0% or less Si, 0.4-2.0% Mn, 0.001-0.2% P, 0.2-0.69% S, less than 0.01% Pb, 0.2% or less Al, 0.001 to 0.02% O and 0.001 to 0.02% N, with the balance being Fe and impurities and in which the contents of Mn and S meet relations of [Mn%]×[S%]<0.9 and [S%]<0.32×[Mn%]5. Further the above low-carbon sulfur-based free cutting steel may contain one or more elements out of either or both of groups (a) and (b) mentioned below : group (a) consisting of Cu, Ni, Cr, Mo, V and Nb and group (b) consisting of Ti, Se, Te, Bi, Sn, Ca, Mg and rare earth elements. |