| 摘要 |
An inexpensive high Cr ferritic stainless steel having excellent corrosion resistance, elongation, stretchability, and pipe expanding properties by reducing the content of Mo, increasing the content of Cr, properly controlling C%+N%, C%/N%, and Ti%/(C%+N%), controlling contents of Ca, Mg, and Zr, and controlling slab heating temperature, finish rolling temperature, and hot and cold annealing conditions is provided, and a method of manufacturing the same is provided. A ferritic stainless steel having excellent corrosion resistance and stretchability is characterized in that an EL value defined by a mathematical expression, EL=-162.1x(C+N)-0.2xCr-1.1xMo-0.2xTi/(C+N)+42.2, of stainless steel comprising, by weight percent, 0.03% or less of C, 0.5% or less of Si, 0.5% or less of Mn, 0.035% or less of P, 0.01% or less of S, 18 to 21% of Cr, 0.5% or less of Mo, 0.030% or less of N, 0.5% or less of Cu, 0.05% or less of Al, 0.2% or less of Ni, 0.014% or less of C+N, 0.4% or less of Ti, and the balance of Fe and other inevitably added impurities is controlled to not less than 31, and a P.I. value defined by a mathematical expression, P.I.=Cr+3.3Mo, of the stainless steel not less than 21. The ferritic stainless steel having excellent corrosion resistance and stretchability comprises one or more selected from the group consisting of 0.005 wt.% or less of Ca, 0.005 wt.% or less of Mg, and 0.01 wt.% or less of Zr. The C/N ratio satisfies a value that is not more than 1.05, and the Ti(C+N) ratio satisfies a value from 18 to 25. |
