Compositional and microstructural effects on hydrogen embrittlement of ASTM grade 12 titanium (TI 0. 3 Mo - 0. 8 Ni)

Technical Report · Thu May 01 04:00:00 EDT 1986

OSTI ID:5851496

Moody, N R; Robinson, S L

This study characterized the effects of alloy composition, microstructure, and hydrogen on ASTM grade 12 titanium tensile properties and fracture. The effect of alloy composition on the tensile properties agreed with previous studies. Mo, Fe, and O each increased the yield and ultimate tensile strengths and the fracture stress in all heats studied. Ni had little effect on the yield and ultimate strengths but decreased the fracture stress. Mo and Fe increased ductility, whereas, Ni and O decreased it. In contrast, hydrogen increased the ultimate tensile strength but decreased the yield strength, fracture stress and ductility. The decrease in properties was independent of alloy composition. However, the amount of hydrogen-induced secondary cracking exhibited significant heat-to-heat variation which was directly related to the microstructure. Alloy heats with a well-defined banded microstructure and significant amount of intergranular ..beta.. exhibited more hydrogen-induced secondary cracking than alloy heats with poorly-defined banded microstructures or less intergranular ..beta... These results showed that grade 12 titanium used for high-level nuclear waste storage applications should have the lowest total concentration of alloying elements required to provide adequate toughness and corrosion resistance. The alloy should also be fully annealed to reduce the severity of microstructural banding and the amount of intergranular ..beta... The low concentration of alloying elements and a full anneal will reduce susceptibility to hydrogen embrittlement.

• Research Organization: Sandia National Labs., Livermore, CA (USA)
• DOE Contract Number: AC04-76DR00789
• OSTI ID: 5851496
• Report Number(s): SAND-85-8247; ON: DE86011379
• Country of Publication: United States
• Language: English

Related Subjects

052002 -- Nuclear Fuels-- Waste Disposal & Storage
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
ALLOYS
CHEMICAL COMPOSITION
CONTAINERS
CRYSTAL STRUCTURE
DUCTILITY
EMBRITTLEMENT
FAILURES
FRACTURES
HIGH-LEVEL RADIOACTIVE WASTES
HYDROGEN EMBRITTLEMENT
MANAGEMENT
MATERIALS
MECHANICAL PROPERTIES
MICROSTRUCTURE
MOLYBDENUM ADDITIONS
MOLYBDENUM ALLOYS
NICKEL ADDITIONS
NICKEL ALLOYS
RADIOACTIVE MATERIALS
RADIOACTIVE WASTE STORAGE
RADIOACTIVE WASTES
STORAGE
TENSILE PROPERTIES
TITANIUM ALLOYS
TITANIUM BASE ALLOYS
WASTE MANAGEMENT
WASTE STORAGE
WASTES