ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Recrystallization behavior of SPD processed high purity iron was studied. The 99.95%iron sheet was deformed by the accumulative roll-bonding (ARB) process up to 8 cycles (equivalentstrain of 6.4) at ambient temperature. Subsequently, the ARB-processed specimens were annealed for1.8ks at various temperatures from 300°C to 500°C. The microstructures of these specimens werecharacterized by TEM and SEM/EBSP. The microstructure of the as-ARB-processed specimensshowed the lamellar boundary structure elongated along RD, which was the typical microstructure ofthe ARB-processed materials. The mean interval of the lamellar boundaries was about 100 nm. Afterannealing at 400°C, the ARB specimen showed a partially recrystallized microstructure composed ofequiaxed grains with grain size larger than 10 5m and the recovered lamellar boundary structure.After annealing above 500°C, the microstructures were filled with equiaxed recrystallized grains.These results suggest that conventional discontinuous recrystallization characterized by nucleationand growth occurs during annealing at annealing temperature above 400 ºC. In previous workreported about the annealing behavior of the low carbon IF steel ARB processed, the continuousrecrystallization occurred during annealing at annealing temperature above 600 ºC. Therecrystallization temperature of the pure iron was much lower than the IF steel and therecrystallization process were significantly different. This difference was suggested to be caused byinhomogeneous microstructure in the pure iron ARB-processed
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/17/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.558-559.357.pdf
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