| 摘要 |
<p>Parent Patent described a Ni-Cr superalloy suitable for casting objects such as gas turbine components exposed to corrosive media at high temp. The improvement comprises the addn. of hafnium such that the alloy has compsn. 14-22% Cr, 5-25% Co, 1-5% W, 0.5-3% Ta, 2-5% Ti, 1-4.5% Al, 4.5-9% Ti+Al, 0-2% Nb, 0.3-1.2% B, 0-3.5% Mo, 0-0.5% Zr, 0-0.2% Y and/or La, 0-0.1% C, =2.2% Hf, and =2% V; the remainder is Fe with impurities caused by melting. The pref. alloy contains 0.05-1.7% Hf, esp. 0.3-1.3% Hf, 0.5-1.5% esp. 0.5-1.3% V; 0.4-1 esp. 0.5-1% B; =0.05% C; 15-21% Cr; max. 17% Cr; or min. 19% Cr; 5-22% Co; 0.8-2.5% Ta, 0.5% max. Nb. The alloy is used esp. for parts requiring high creep strength and corrosion resistance at high temp. Used esp. in chill casting to obtain parts with columnar structure, where Hf and V improve creep strength and hot toughness.</p> |
