S. F. Sternasty
Published: 1966
Total Pages: 118
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A research program aimed toward the development of a wrought nickel-base sheet alloy with a high strength-to-weight advantage up to 1400 degree F is described. The target properties were 1000 hour stress rupture strength to density ratio of 250,000 inches and 150,000 psi .2% yield strength, both at 1400 degree F. Laboratory heats were melted, processed to sheet, and tested. Several alloys exhibited yield strengths in excess of 180,000 psi at 1400 degree F with rupture strengths better than current high yield strength sheet alloys. None of the alloys, however, had the desired ductilities and stress rupture lives. The alloys selected for further evaluation were based on a statistical analysis of the chemical composition and mechanical property data generated on the previous heats. By exploitation several alloys were identified that combined exceedingly high yield strength with ductility. The best alloys had an extrapolated 1400 degree F/1000 hour rupture strength of 67,000 psi, which is about 10,000 psi over the best commercially available wrought alloy, U-700.