| 摘要 |
<p>An alloy suitable for high temp. service and having low thermal expansion and freedom from notch sensitivity and deleterious microshrinkage, comprises 30-50% Ni, 10-20% Co, up to 5 (pref. 2-4)% Nb, up to 3% (pref. 0-1) Ta, up to 2.5 (pref. 1-2)% Ti, up to 0.1 (pref. 0.015-0.045)% C, up to 2.0 (pref. 0.25-1)% Al, 0.06-0.3% b, up to 0.1% Zr, up to 0.1% rare earths, up to 1.0% Hf, balance Fe. The alloy contains a eutectic boride. The alloy may also contains up to 0.1% Mg, Ca, Sr, Ba, up to 3% Mo and up to 3% W. The alloy is suitable for use in rocket engines. The eutectic boride which forms during solidification improves the cartabality of the alloy without affecting the low thermal expansion characteristics. The alloys have a wide liquidus to solidus range and can bec art or hot-worked and used in wrought from (provided a heat treatment for the wrought form is provided).</p> |
