| 摘要 |
PROBLEM TO BE SOLVED: To increase equiaxed crystal ratio and to improve ridging resistance by specifying respective contents of Cr, C, Si, Mn, N, and Ti in a steel and controlling the form of an inclusion consisting of TiN alone so that its area ratio takes a value in a specific range. SOLUTION: This ferritic stainless steel has a composition consisting of, by weight, 9-32% Cr, <=0.15% C, <=1.0% Si, <=1.0% Mn, 0.003-0.06% N, 0.01-1.0% Ti, and the balance essentially Fe. Further, an inclusion consisting of TiN alone is allowed to exist in an amount of >=0.01% by area ratio. When the area ratio of the single-type TiN precipitating in the molten metal becomes >=0.01%, a slab of >=60% equiaxed crystal ratio can be obtained without requiring particular devices and difficult casting conditions. In the alloy composition, higher Cr content is preferable and lower C content is preferable. Mn has functions of improving manufacturability and fixing harmful S in the form of MnS. N is a component necessary to form TiN which is used as a nucleus of solidification of ferrite.
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