FERRITIC ANTI-BACTERIAL STAINLESS STEEL BEARING Cu AND Nb ELEMENTS, AND METHOD OF MANUFACTURING THEREOF

摘要

PURPOSE: A ferritic anti-bacterial stainless steel bearing Cu and Nb elements is provided, wherein -Cu precipitate formed by aging increases the release amount of Cu¬+2 thus improving anti-bacterial effect. CONSTITUTION: In a manufacture method of ferritic stainless steel sheet including hot rolling, cold rolling and annealing, the method is characterized in that after annealing a steel sheet comprising 0.03 wt.% or less of C, 0.5 wt.% or less of Si, 0.025 wt.% or less of P, 0.010 wt.% or less of S, 0.03 wt.% or less of N, Cr 16.5 to 17.5 wt.%, Cu 1.0 to 1.6 wt.%, 1.0 wt.% or less of Ni, Nb 0.4 to 0.6 wt.%, a balance of Fe and incidental impurities is cooled in furnace after held at 400 to 600 deg.C for 20 to 40 min to disperse -Cu precipitate with diameter of 0.2 to 0.5 micrometer and NbO in the steel sheet, wherein the weight ratio of C+N in the steel sheet is less than 0.05 wt.% and the limited drawing ratio is greater than 2.2.