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:
Ultrafine-grained steel sheets with the chemical composition of 0.15%C-0.74%Mn-0.01%Si have been prepared using a laboratory rolling mill by Super Short Interval Multi-passRolling (SSMR) process, in which the inter-pass time is extremely shortened to enhance thecumulative strain. The SSMR process with a finish rolling around Ae3 leads to ultrafine equiaxedferrite structure with 1μm in average grain size. In order to clarify the grain refinement mechanismin the SSMR process, the deformation substructure in deformed austenite was simulated using70%Ni-30%Fe, which was a fcc alloy with equivalent stacking fault energy to C-Mn steels. TEMobservations have shown that the dislocation substructure in the Ni-Fe alloy hot-rolled by SSMRprocess mainly consists of dislocation cells, of which size are refined to less than 1μm withshortening inter-pass time. It is concluded that the SSMR process can accumulate the deformationstrain in austenite enough to densely nucleate ferrite inside austenite grains
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/15/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.539-543.4698.pdf
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