Hydrogen-induced fracture characteristics of single crystal nickel-based superalloy

Thesis/Dissertation · Mon Jan 01 04:00:00 EST 1990

OSTI ID:5281229

Chen, Po-Shou

A stereoscopic method was developed and applied to the fracture surface of PWA 1480E single crystal nickel-based superalloy to permit rapid orientation determinations of small cleavage planes. The microstructure of PWA 1480E was characterized before fracture analysis was performed. The bucoid morphology of the gamma prime precipitate was not influenced by the crystal growth orientation. The amount of lattice mismatch and lattice misorientation between gamma/gamma prime in PWA 1480E was not affected by the single crystal growth orientation. Notched single crystals with seven different crystal growth orientations were tensile tested at room temperature in a helium atmosphere at 34 MPa, and notched single crystals with seven different crystal growth orientations were also tensile tested at room temperature in a hydrogen atmosphere at 34 MPa. In order to understand the temperature dependence of hydrogen-induced embrittlement, notched single crystals with three different crystal growth orientations were tensile tested at 1600 F in helium and hydrogen atmospheres at 34 MPa. Results of the environmentally controlled tests are given and briefly discussed.

• Research Organization: Auburn Univ., AL (United States)
• OSTI ID: 5281229
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
ALLOYS
CLEAVAGE
CRYSTAL GROWTH
CRYSTAL STRUCTURE
CRYSTALS
ELEMENTS
EMBRITTLEMENT
FLUIDS
FRACTURE PROPERTIES
GASES
HELIUM
HYDROGEN
HYDROGEN EMBRITTLEMENT
MECHANICAL PROPERTIES
MICROSTRUCTURE
MONOCRYSTALS
MORPHOLOGY
NICKEL ALLOYS
NICKEL BASE ALLOYS
NONMETALS
RARE GASES
TEMPERATURE DEPENDENCE