Mechanisms of time-dependent crack growth at elevated temperature. Final project report, July 1, 1986--August 31, 1989

Technical Report · Sun Apr 15 00:00:00 EDT 1990

DOI:https://doi.org/10.2172/10142352· OSTI ID:10142352

Saxena, A; Stock, S R

Objective of this 3-y study was to conduct creep and creep-fatigue crack growth experiments and to characterize the crack tip damage mechanisms in a model material (Cu-1wt%Sb), which is known to cavitate at grain boundaries under creep deformation. Results were: In presence of large scale cavitation damage and crack branching, time rate of creep crack growth da/dt does not correlate with C{sub t} or C{sup *}. When cavitation damage is constrained, da/dt is characterized by C{sub t}. Area fraction of grain boundary cavitated is the single damage parameter for the extent of cavitation damage ahead of crack tips. C{sub t} is used for the creep-fatigue crack growth behavior. In materials prone to rapid cavity nucleation, creep cracks grow faster initially and then reach a steady state whose growth rate is determined by C{sub t}. Percent creep life exhausted correlates with average cavity diameter and fraction of grain boundary area occupied by cavities. Synchrotron x-ray tomographic microscopy was used to image individual cavities in Cu-1wt% Sb. A methodology was developed for predicting the remaining life of elevated temperature power plant components; (C{sub t}){sub avg} was used to correlate creep-fatigue crack growth in Cr-Mo and Cr-Mo-V steel and weldments.

• Research Organization: Georgia Inst. of Tech., Atlanta, GA (United States). School of Material Engineering
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: FG05-86ER45257
• OSTI ID: 10142352
• Report Number(s): DOE/ER/45257-T2; ON: DE93012228
• Resource Relation: Other Information: PBD: 15 Apr 1990
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
20 FOSSIL-FUELED POWER PLANTS
COPPER BASE ALLOYS
CREEP
CRACK PROPAGATION
POWER PLANTS
PROGRESS REPORT
TEMPERATURE RANGE 0400-1000 K
ANTIMONY ADDITIONS
DAMAGE
CAVITATION
GRAIN BOUNDARIES
SERVICE LIFE
FORECASTING
CHROMIUM-MOLYBDENUM STEELS
360103
200104
MECHANICAL PROPERTIES
COMPONENTS