Patent ID: 8894924

Claim:
A ferrite stainless steel with low black spot generation in welded portions, comprising: by mass %, C: 0.020% or less; N: 0.025% or less; Si: 0.25% or less; Mn: 0.5% or less; P: 0.035% or less; S: 0.01% or less; Cr: 19.1 to 22.6%; Al: 0.04% to 0.13%; Ti: 0.05% to 0.19%; Ca: 0.0003% to 0.0015%; either one or both of V: 0.05% to 0.2% and Zr: 0.05% to 0.2%; and a balance of Fe and unavoidable impurities, wherein the stainless steel has a BI value ≦0.8, and BI=3Al+Ti+0.5Si+200Ca.