| 摘要 |
PROBLEM TO BE SOLVED: To improve the ridging resistance of a ferritic stainless steel by prescribing the amt. and size of precipitates in a steel. SOLUTION: At first, this steel is incorporated with Cr by >=11wt.% from the viewpoint of corrosion resistance. Since Ti plays an important roll for suppressing the generation of ridging, the formation of the sulfide, carbide and nitride thereof is effective, and particularly, in the case of >=3Ti/(C+N+S), its ridging resistance is remarkably improved. Then, the carbide + nitride + sulfide having <=3μm grain size are present by >=1 piece per (dmean )<2> in the case the average grain size of the steel sheet is defined as dmean , and the volume ratio thereof is regulated to <=0.5%. This is because the precipitates having <=3μm grain size prevent the formation of (100) colonies and a band-shaped structure at the time of recrystallization after cold rolling suppresses the generation of ridging. Furthermore, by prescribing the number and volume ratio of the above precipitates, its ridging resistance can furthermore be improved.
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