| 摘要 |
PROBLEM TO BE SOLVED: To provide a slab of high Cr steel containing >=1% Cr and extremely small in porosities and cracks in the central part as-cast and to provide a seamless steel pipe of high Cr steel free from flaws at the inside and good in internal properties. SOLUTION: This high Cr steel slab and seamless steel pipe have a composition containing, by mass, 0.001 to 0.3% C, 0.1 to 1% Si, 0.1 to 5% Mn, <=0.04% P, <=0.01% S, 1 to 30% Cr, 0.001 to 0.1% Al, <=0.1% O(oxygen) and <=0.5% N, and if required, further containing Ni, Mo, W, Cu, Nb, Ti, Zr and V, and the balance Fe with impurities and moreover satisfying the following inequality (1) and have a metallic structure containing a ferritic phase of >=5 vol.%: Cr+3 Mo+Nb+4V+7-(190C+120N+4Ni+8Cu+4Si+12Al+2W)>=0.
|
