Influence of subsolvus thermomechanical processing on the low-cycle fatigue properties of HAYNES 230 alloy

Journal Article · Wed Mar 01 04:00:00 EST 1995 · Metallurgical Transactions, A

DOI:https://doi.org/10.1007/BF02663917· OSTI ID:31974

Vecchio, K S; Fitzpatrick, M D ^[1]; Klarstrom, D ^[2]

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1. Univ. of California, San Diego, La Jolla, CA (United States). Dept. of Applied Mechanics and Engineering Sciences
2. Haynes International, Kokomo, IN (United States). Technology Dept.

Strain-controlled low-cycle fatigue tests have been conducted in air at elevated temperature to determine the influence of subsolvus thermomechanial processing on the low-cycle fatigue (LCF) behavior of HAYNES 230 alloy. A series of tests at various strain ranges was conducted on material experimentally processed at 1,121 C, which is below the M{sub 23}C{sub 6} carbide solvus temperature, and on material fully solution annealed at 1,232 C. A comparative strain-life analyses was performed on the LCF results, and the cyclic hardening/softening characteristics were examined. At 760 C and 871 C, the fatigue life of the experimental 230/1121 material was improved relative to the standard 230/1232 material up to a factor of 3. The fatigue life advantage of the experimental material was related primarily to a lower plastic (inelastic) strain amplitude response for a given imposed total strain range. It appears the increase in monotonic flow stress exhibited by the finer grain size experimental material has been translated into an increase in cyclic flow stress at the 760 C and 871 C test temperature. Both materials exhibited entirely transgranular fatigue crack initiation and propagation modes at these temperature. The LCF performance of the experimental material in tests performed at 982 C was improved relative to the standard material up to a factor as high as 2. The life advantage of the 230/1121 material occurred despite having a larger plastic strain amplitude than the sandbar 230/1232 material for a given total strain range.

• Sponsoring Organization: USDOE
• OSTI ID: 31974
• Journal Information: Metallurgical Transactions, A, Journal Name: Metallurgical Transactions, A Journal Issue: 3 Vol. 26; ISSN 0360-2133; ISSN MTTABN
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
DATA ANALYSIS
EXPERIMENTAL DATA
FATIGUE
HEAT RESISTING ALLOYS
MECHANICAL TESTS
NICKEL BASE ALLOYS
SERVICE LIFE
STRAIN HARDENING
STRAIN SOFTENING
THERMOMECHANICAL TREATMENTS