PURPOSE: To produce a heat-resistant cast steel casing high in creep fracture strength at a high temp., having good weldability and used for a supercritical turbine in which the main steam temp. and pressure are regulated to 621°C and 250kgf/cm2, respectively.
CONSTITUTION: This casing is constituted of a heat-resistant cast steel contg., by weight, 0.06 to 0.16% C, <0.4% Si, <1% Mn, 8 to 12% Cr, 0.2 to 0.9% Ni, 0.05 to 0.3% V, 0.01 to 0.15% Nb, 0.01 to 0.08% N, <1% Mo, >1 to <3% W, <0.0027% B, and the balance substantial Fe. The ratio of Ni/W is preferably regulated to 0.25 to 0.75, furthermore, at least one kind of ≤0.15% Ta and ≤0.1% Zr may be added, and moreover, the Cr equivalent calculated by the following formula is preferably regulated to 4 to 10: the Cr equivalent = Cr+6Si+4Mo+1.5W+11V+5Nb-40C-30N-30B-2Mn-4Ni-2Co.
KURIYAMA MITSUO
HIDAKA KISHIO
NAKAMURA SHIGEYOSHI
FUKUI HIROSHI
FUJITA TOSHIO
| JPS60128250A | 1985-07-09 | |||
| JPS5970752A | 1984-04-21 | |||
| JPH02149649A | 1990-06-08 | |||
| JPS61133365A | 1986-06-20 | |||
| JPH02310340A | 1990-12-26 | |||
| JPS60200912A | 1985-10-11 |
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