Abstract
The simulation of microstructural evolution during the primary breakdown of production-sized alloy 718 ingots and billets by radial forging was accomplished in the laboratory via multiple-stroke axial compression testing of cylindrical specimens. The dwell or hold time between strokes was varied to simulate the deformation-time history for three different locations along the radial-forging work piece: lead-end, mid-length, and tail-end positions. The microstructural evolution varied with simulated work piece position. Static, rather than dynamic, recrystallization was responsible for the observed grain-size refinement, and its repetitive occurrence during consecutive dwell periods resulted in the maintenance of a fine-grain microstructure during multiple-stroke deformation sequences. For comparison, the total plastic strain was also applied in a single-stroke test. The single- and multiple-stroke techniques gave differing microstructural results, indicating that multiple-stroke testing is necessary in modeling microstructural evolution during primary breakdown.
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Additional information
Martin C. Mataya earned his Ph.D. in metallurgical engineering at Marquette University in 1974. He is currently a research professor at the Advanced Steel Processing and Products Research Center at the Colorado School of Mines and a staff member in the Materials Science and Technology Division at Los Alamos National Laboratory. Dr. Mataya is a member of TMS.
For more information regarding the Advanced Steel Processing and Products Research Center, contact D. Matlock at (303) 273-3775.
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Mataya, M.C. Simulating microstructural evolution during the hot working of alloy 718. JOM 51, 18–26 (1999). https://doi.org/10.1007/s11837-999-0006-x
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DOI: https://doi.org/10.1007/s11837-999-0006-x