Relationship between Yield Point Phenomena and the Nanoindentation Pop-in Behavior of Steel

Journal Article · Sun Jan 01 04:00:00 EST 2012 · Journal of Materials Research

DOI:https://doi.org/10.1557/jmr.2011.208· OSTI ID:1033150

Ahn, T. -H. ^[1]; Oh, C. -S. ^[2]; Lee, K. ^[3]; George, Easo P ^[4]; Han, H. N. ^[1]

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1. Seoul National University
2. Korean Institute of Materials Science
3. Technical Research Laboratories, Republic of Korea
4. ORNL

Pop-ins on nanoindentation load-displacement curves of a ferritic steel were correlated with yield drops on its tensile stress-strain curves. To investigate the relationship between these two phenomena, nanoindentation and tensile tests were performed on annealed specimens, prestrained specimens, and specimens aged for various times after prestraining. Clear nanoindentation pop-ins were observed on annealed specimens, which disappeared when specimens were indented right after the prestrain, but reappeared to varying degrees after strain aging. Yield drops in tensile tests showed similar disappearance and appearance, indicating that the two phenomena, at the nano- and macro-scale, respectively, are closely related and influenced by dislocation locking by solutes (Cottrell atmospheres).

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1033150
• Journal Information: Journal of Materials Research, Journal Name: Journal of Materials Research Journal Issue: 1 Vol. 27; ISSN JMREEE; ISSN 0884-2914
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
DISLOCATIONS
FERRITIC STEELS
SOLUTES
STEELS
STRAIN AGING
STRESS ANALYSIS
TENSILE PROPERTIES