Aging and Phase Stability Studies of Alloy 22 FY08 Final Report

Technical Report · Thu Apr 03 04:00:00 EDT 2008

DOI:https://doi.org/10.2172/945143· OSTI ID:945143

Torres, S G

This report is a compilation of work done over the past ten years in support of phase stability studies of Alloy 22 for the Yucca Mountain Project and contains information previously published, reported, and referenced. Most sections are paraphrased here for the convenience of readers. Evaluation of the fabrication processes involved in the manufacture of waste containers is important as these processes can have an effect on the metallurgical structure of an alloy. Because material properties such as strength, toughness, aging kinetics and corrosion resistance are all dependent on the microstructure, it is important that prototypes be built and evaluated for processing effects on the performance of the material. Of particular importance are welds, which have an as-cast microstructure with chemical segregation and precipitation of complex phases resulting from the welding process. The work summarized in this report contains information on the effects of fabrication processes such as solution annealing, stress mitigation, heat-to-heat variability, and welding on the kinetics of precipitation, mechanical, and corrosion properties. For a waste package lifetime of thousands of years, it is impossible to test directly in the laboratory the behavior of Alloy 22 under expected repository conditions. The changes that may occur in these materials must be accelerated. For phase stability studies, this is achieved by accelerating the phase transformations by increasing test temperatures above those anticipated in the proposed repository. For these reasons, Alloy 22 characterization specimens were aged at Lawrence Livermore National Laboratory (LLNL) Aging Facilities for times from 1 hour up to 8 years at temperatures ranging from 200-750 C. These data as well as the data from specimens aged at 260 C, 343 C, and 427 C for 100,028 hours at Haynes International will be used for performance confirmation and model validation.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA
• Sponsoring Organization: USDOE
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 945143
• Report Number(s): LLNL-TR-403968
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
22 GENERAL STUDIES OF NUCLEAR REACTORS
AGING
ALLOYS
ANNEALING
CONTAINERS
CORROSION
CORROSION RESISTANCE
FABRICATION
KINETICS
LIFETIME
MICROSTRUCTURE
MITIGATION
PHASE STABILITY
PHASE TRANSFORMATIONS
PRECIPITATION
SEGREGATION
VALIDATION
WASTES
WELDING
YUCCA MOUNTAIN