PROCESS DEVELOPMENT FOR PRECISION FORGING COLUMBIUM BASE ALLOYS.
Abstract
A program to develop a process for precision tolerance forgings of medium and high strength columbium alloys has been successfully completed. Preliminary studies established process parameters. The program objective was then met by specific process development trails followed by pilot production forging of Cb-752 to a structural shape, and of Cb-132M to a gas turbine rotor blade. Dimensional evaluation of the Cb-752 forgings demonstrated that thicknesses were reproducible within a + or -0.007 inch tolerance band. Mechanical test results showed that the program target of 20,000 psi ultimate strength at 2400 F was exceeded in forged and heat treated Cb-752 alloy before and after application of a Cr-Ti-Si service coating. Thickness tolerances within + or - 0.005 inch were achieved in the Cb-132M forgings, and airfoil contour and twist dimensions were within the precision tolerances required for turbine blade use. The Cb-132M forgings provided 2400 F ultimate strengths in excess of the program target of 45,000 psi in both the as-forged and the forged and annealed conditions. Application of the service coating moderately decreased the tensile properties of the Cb-132M alloy. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1967
- Accession Number
- AD0814808
Entities
People
- Charles R. Smeal
- Frank N. Lake