This report summarizes research conducted during the fourth year of the five year Steam Generator Group Project. During this period the project conducted numerous nondestructive examination (NDE) round robin inspections of the original Surry 2A steam generator. They included data acquisition/analysis and analysis-only round robins using multifrequency bobbin coil eddy current tests. In addition, the generator was nondestructively examined by alternate or advanced techniques including ultrasonics, optical fiber, profilometry and special eddy current instrumentation. The round robin interpretation data were compared. To validate the NDE results and for tube integrity testing, a selection of tubing samples, determined to be representative of the generator, was designated for removal. Initial sample removals from the generator included three sections of tube sheet, two sections of support plate and encompassed tubes, and a number of straight and U-bend tubing sections. Metallographic examination of these sections was initiated. Details of significant results are presented in the following paper.

: A design study has been conducted to establish an engineering specification for an integrated inspection system that will be used to implement the Retirement for Cause (RFC) maintenance philosophy on gas turbine engine disks and spacers. The system specified by this study emphasizes equipment reliability, flexibility, component throughput and accountability required for 1985 overhaul facility implementation through an Air Force manufacturing technology program. NDE technology needs for far term (post-1985) overhaul implementation of optimal RFC inspections are discussed in terms of necessary research programs which should be conducted in parallel to the manufacturing technology effort. Keywords: Retirement for Cause, Nondestructive Evaluation, F100 Engine, Engine Maintenance, Eddy Current, Ultrasonic Test, Fluorescent Penetrant Inspection, Automated Facility.

The internal friction spectra of some titanium and zirconium alloys were measured from 4 to 300°K. These spectra show a peak in the vicinity of 180°K (at 120 kHz). This peak was found to be associated with the beta phase and not with β-ω interface as has been previously suggested by Nelson et al. These data are discussed in terms of the special electronic properties of the titanium group elements. An analysis of the omega structure suggests that, on alloying with other transition metals, the titanium group elements can exist in two different electronic configurations. The existence of these two electronic species in the b.c.c. beta phase results in stabilized or bound vacancies which account for the anomalous diffusion behavior in the titanium group elements. These vacancies and their stabilizing complex constitute defects in the b.c.c. lattice and these defects are responsible for the internal friction peak observed in the vicinity of 180°K in b.c.c. titanium group element alloys.