NSTD Research Projects: TRP

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Proposals

Year 1
Year 2
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Quarterly Reports

2002: 3rd, 4th
2003: 1st, 2nd, 3rd, 4th
2004: 1st, 2nd, 3rd, 4th
2005: 1st, 2nd, 3rd, 4th
2006: 1st, 2nd, 3rd, 4th

Annual Reports

2002-2003 (submission)
2003-2004
2004-2005
2005-2006
2006-2007

Other

Task Products

TRP -> Campaign/Number -> TRP 14

TRP 14. Use of Positron Annihilation Spectroscopy for Stress-Strain Measurements

Research Objectives & Methods

The primary objective of this task was to evaluate the feasibility of the characterization of residual stresses in plastically-deformed and welded structural materials using a new nondestructive technique based on PAS. The residual stresses measured by a modified PAS method have been compared to those measured by three other techniques, namely the Ring-Core (destructive), X-Ray Diffraction (non-destructive), and Neutron Diffraction (non-destructive).

All four techniques have been used to evaluate residual stresses in cold-worked, plastically deformed and welded specimens of austenitic Type 304L Stainless Steel (SS), and martensitic Alloys EP-823 and HT-9. Alloy EP-823 is a leading target structural material to contain the molten lead-bismuth eutectic nuclear coolant needed for fast spectrum operations of an Accelerator-Driven Transmutation System. Type 304L SS is a universally-known corrosion resistant low-carbon iron-nickel-chrome alloy having optimum formability and weldability. Alloy HT-9 is known for its superior high temperature tensile properties. The metallurgical microstructures and the nature of defects have been analyzed by optical microscopy, scanning electron microscopy, and TEM.

Researchers

• Ajit Roy, Mechanical Engineering

Collaborators

• Stuart Maloy, AFCI Materials Team Leader, Los Alamos National Laboratory
• J. Frank Harmon, Director, Idaho Accelerator Center, Idaho State University
• Doug Wells, Associate Professor, Department of Physics, Idaho State University
• Farida Selim, Post Doctoral Researcher, Idaho Accelerator Center, Idaho State University

Students

• Subhra Bandyopadhyay, Masters, Mechanical Engineering
  (MS Thesis Not Available)
• Silpa Suresh Budugur, Masters, Mechanical Engineering
  (MS Thesis Not Available)
• Srinivas Chanda, Masters, Mechanical Engineering
  (MS Thesis Not Available)
• Satish Babu Dronovalli, Masters, Mechanical Engineering
  MS Thesis
• Raghunandan Karamcheti, Masters, Mechanical Engineering
• Vikram Marthandam, Masters, Mechanical Engineering MS Thesis
• Anand Venkatesh, Masters, Mechanical Engineering
  MS Thesis
• Bhagath Yarlagadda, Masters, Mechanical Engineering