Abstract: The(C+N)content in ultra purity ferritic stainless steels is ≤150×10-⁶,its corrosion resistance, weldability and toughness are obviously higher than that of common ferritic stainless steels. The grade,chemical com- position and properties of new developed ultra purity fernitic stainless steels including modified 409,429 and modi- fied,444 and modified steels are presented; and by using 3- step steel making process to produce 18Cr ultra purity ferritic stainless steels, with SS-VOD refining,the(carbon + nitrogen)content in steel-[C+N] is≤70×10^-6, with VOD-PB refining,[C+N] is 80×10^-6,and with VCR refining,[C+N] is(80～100)×10^-⁶.

摘要： 超纯铁素体不锈钢中(C+N)含量≤150×10- °,其耐蚀性、焊接性能、韧性等显著高于普通铁素  体不锈钢。介绍了新开发的409改进型、429及改进型、444及改进型超纯铁素体不锈钢的钢种、成分和性能； 采用三步法工艺冶炼18Cr超纯铁素体不锈钢，用SS-VOD 精炼时，钢中[C+N]≤70×10-⁶ ;VOD-PB 精炼时， [C+N] 为80×10-⁶ ;VCR 精炼时，[C+N] 为(80~100)×10-⁶。