To provide a billet which suppresses the generation of an intermetallic compound entailing the deterioration of toughness and corrosion resistance and a seamless steel tube using the billet.
There are provided the billet for the seamless steel tube which contains 0.05% C, 0.10 to 1.00% Si, 0.1 to 1.5% Mo, 20.0 to 30.0% Cr, 50 to 11.0% Ni, 2.5 to 4.0% Mo, 0.001 to 0.100% Al, and 0.05 to 0.50% N, and the balance Fe with inevitable impurities, and 0.010%S and 0.04%P in the impurities and when the drilled radius is defined as R0, a drilled radius of the billet as X, the distance from the center of the billet cross section to an arbitrary segregation part position as R, and the degree of segregation of Mo in that position as S, and when the billet is not subjected to drilling work, the relation of formula: S-2/{(R2/X2)x100}-10 is satisfied, and when the billet is subjected to the drilling work, the relation of formula: S-2/{(R2-X2)/(R02-X2)x100}-10 is satisfied, and the seamless steel tube manufactured by using the billet.
TERUNUMA MASAAKI
TAKABE HIDEKI
HAYASHI HIROSHI
KUBO YASUSHI
| JPH04165019A | 1992-06-10 |
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