skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Alloy 617 Creep-fatigue Damage Evaluation Using Specimens with Strain Redistribution

 [1];  [1];  [2]
  1. ORNL
  2. Consultant
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
OSTI Identifier:
DOE Contract Number:
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Pressure Vessel Technology; Journal Volume: 137
Country of Publication:
United States

Citation Formats

Wang, Yanli, Sham, Sam, and Jetter, Robert I. Alloy 617 Creep-fatigue Damage Evaluation Using Specimens with Strain Redistribution. United States: N. p., 2015. Web. doi:10.1115/1.4031548.
Wang, Yanli, Sham, Sam, & Jetter, Robert I. Alloy 617 Creep-fatigue Damage Evaluation Using Specimens with Strain Redistribution. United States. doi:10.1115/1.4031548.
Wang, Yanli, Sham, Sam, and Jetter, Robert I. 2015. "Alloy 617 Creep-fatigue Damage Evaluation Using Specimens with Strain Redistribution". United States. doi:10.1115/1.4031548.
title = {Alloy 617 Creep-fatigue Damage Evaluation Using Specimens with Strain Redistribution},
author = {Wang, Yanli and Sham, Sam and Jetter, Robert I},
abstractNote = {},
doi = {10.1115/1.4031548},
journal = {Journal of Pressure Vessel Technology},
number = ,
volume = 137,
place = {United States},
year = 2015,
month = 1
  • This paper studies tension/torsion multiaxial low-cycle fatigue lives and creep-fatigue damage evaluation for Alloy 738LC superalloy. Tension/torsion creep-fatigue tests were carried out using hollow cylinder specimens and multiaxial creep-fatigue lives were obtained. The Mises' equivalent strain correlated the multiaxial low cycle fatigue lives within a factor of two scatter band. An a.c. potential method is developed to detect the creep-fatigue damage associated with crack nucleation and extension. A.c. potentials at high frequencies accurately detect the creep-fatigue damage from the early stage of life while those at low frequencies detect that in the final stage of life. A.c. potentials at highmore » frequencies detect the crack density, defined as the total crack length per unit area, and maximum crack length more sensitivity than those at low frequencies.« less
  • This report is the result of a research program on creep-fatigue damage conducted under a Grant from PVRC on engineering materials such as 316 stainless steel. The main objective of the program is to analyze, evaluate and develop a model for creep-fatigue interaction under uniaxial and biaxial stress/strain cycling at elevated temperature. The biaxial loading was torsion coupled with axial loading with 30 minutes hold-time to generate the creep effect. Data was obtained from fatigue-creep tests conducted at 1,150 F (620 C). Based on test data and in-depth macro-micro analysis, a model which accounts for uniaxial creep damage is developedmore » on the basis of ductility-exhaustion concept. A comparison is made between the proposed ductility exhaustion model and the time fraction rule. The proposed model shows a better and more comprehensive predictive capability than the time fraction rule and was able to distinguish whether the failure is by creep or by low cycle fatigue. For creep-fatigue damage under biaxial state of strain/stress cycling, the uniaxial proposed ductility damage concept was modified to account for the biaxial strain/stress effect.« less
  • Creep and low-cycle fatigue behavior of ferritic Fe-24Cr-04Al alloy was studied in the temperature range of 673 to 873 K, where dynamic strain aging (DSA) occurrence was found. The DSA of the alloy manifested in the form of serrated flow, negative strain rate sensitivity, and the peak or plateau in the variations of yield strength (YS) and ultimate tensile strength (UTS) with temperature. The characteristic creep behavior of the alloy was experimentally verified as that for a class I solid solution. However, this ferritic alloy showed an anomalous high stress exponent (n = 5.7) and high activation energy (Q{sub c}more » = 285 kJ/mol) of the secondary creep, which were commonly exhibited by class II solid solutions. During cyclic deformation, the alloy displayed serration in the stress-strain hysteresis loops, increased cyclic hardening, and enhanced planarity of dislocations. On the basis of the observed experimental results and proper analysis, it was proposed that there was strong elastic interaction between solute aluminum atoms and dislocations in the DSA temperature domain. The anomalous creep and fatigue features were interpreted in terms of the interaction of aluminum with the dislocations.« less
  • Alloy 617 is the leading candidate material for an Intermediate Heat Exchanger (IHX) of the Very High Temperature Reactor (VHTR). To evaluate the behavior of this material in the expected service conditions, strain-controlled cyclic tests that include hold times up to 9000 s at maximum tensile strain were conducted at 950 degrees C. The fatigue resistance decreased when a hold time was added at peak tensile strain, owing to the mechanisms resulting in a change in fracture mode from transgranular in pure fatigue to intergranular in creep–fatigue. Increases in the tensile hold duration beyond an initial value were not detrimentalmore » to the creep–fatigue resistance. An analysis of the evolving failure modes was facilitated by interrupting tests during cycling for ex situ microstructural investigation.« less
  • Cited by 4