SAE AMS5940-1996
Alloy, Corrosion and Heat Resistant, Bars, Forgings, and Rings 34Co - 3.0Cr - 28Ni - 30Cb - 5.5Al - 0.008B - 25.5Fe Multiple Melted, High Temperature, Oxidation Resistant, Low Expansion Solution Heat Treated, Precipitation Hardenable, Specification U