PRODUCTION OF HIGH PURITY STAINLESS STEEL RESISTANT AGAINST OZONE-CONTAINING WATER

摘要

PROBLEM TO BE SOLVED: To improve resistance against ozone-containing water by regulating C, total of Al and Si, single Al, Mn, Cr, Ni, P, S, O and N to specific contents, respectively, with a primary melting under vacuum and specifying the contents of Mn, O and N on and after secondary melting by using the method for a consumable electrode type dissolution. SOLUTION: In the primary melting, the composition of the molten steel is regulated to, by wt.%, <=0.020% C, 1.0-6.0% total of Al and Si or Al single, <=0.18% Mn, 12-30% Cr, 0-35% Ni, <=0.030% P, <=0.010% S, <=0.008% O and <=0.010% N. In the secondary melting, the composition is regulated to <=0.05% Mn, <=0.008% O and <=0.008% N. It is desirable to execute a heating treatment under weak oxidizing atmosphere of 10<-11> -10<-15> MPa gas partial pressure in the total of gaseous oxygen and steam or a nitric acid aqueous solution soaking treatment in 5-50 wt.% concn. or an anode electrolytic treatment for forming a coated film of alminium oxide at <=pH 1, etc., to the surface of a base material using the above cast slab as a blank.