NSTD Research Projects: TRP
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TRP -> Campaign/Number -> TRP 10
TRP 10. Development of a Mechanistic Understanding of High-Temperature Deformation
of Alloy EP-823
August 2001 - August 2004
Research Objectives & Methods
Experimental heats of Alloys EP-823, HT-9 and 422 were vacuum-induction-melted, followed by forging and hot rolling. The hot-rolled bars were subsequently thermally treated to produce a fully tempered and fine-grained martensitic microstructure without any retained austenite. They were austenitized at 1010°C, oilquenched, and tempered at 621°C. The tempering operation was performed for 1.25, 1.75, and 2.25 hours, respectively, to study the effect of tempering time on the tensile properties. The hardness of all materials, before and after tempering, was measured using the Rockwell hardness scale. The tensile properties were determined at temperatures ranging from ambient to 600°C using smooth cylindrical specimens at a strain rate of 10-3 sec-1 according to the ASTM Designation E 8. A minimum of two specimens was tested under each condition, with the average value recorded. The metallurgical microstructures of the tested specimens were evaluated by optical microscopy. The primary fracture surface of the tensile specimens was analyzed by scanning electron microscopy (SEM) to determine the extent and morphology of failure. The resultant data include the percentage elongation (%El), percentage reduction in area (%RA), yield strength (YS), and ultimate tensile strength (UTS) as functions of the testing temperature and thermal-treatments. At least two specimens per material were tested under each of the three metallurgical conditions at the desired temperatures.
Researchers
- Ajit Roy, Mechanical Engineering
- Brendan O'Toole, Mechanical Engineering
Collaborators
- Stuart Maloy, AFCI Materials Team Leader, Los Alamos National Laboratory
Students
- Mark Jones, Masters, Mechanical Engineering
- Prad Koppula, Masters, Mechanical Engineering
- Raymond Kozak, Graduate, Mechanical Engineering
-
Srinivasa Rao Kukatla, Masters, Mechanical Engineering
M.S. Thesis - Martin Lewis, Masters, Mechanical Engineering
-
Venkata Nagarajuna Potluri, Masters, Mechanical Engineering
M.S. Thesis -
Bhagath Yarlagadda, Masters, Mechanical Engineering
M.S. Thesis - John Motaka, Undergraduate (BS), Mechanical Engineering