DBPapers
DOI: 10.5593/SGEM2014/B61/S24.001

A COMPARISON OF THE STRUCTURE AND PROPERTIES OF HSLA STEEL COLD ROLLED AND SEVERE PLASTIC DEFORMED BY HIGH SPEED HIGH PRESSURE TORSION

G. Gurau, P. Alexanu, L. Gurau, V. Musat
Wednesday 1 October 2014 by Libadmin2014

References: 14th International Multidisciplinary Scientific GeoConference SGEM 2014, www.sgem.org, SGEM2014 Conference Proceedings, ISBN 978-619-7105-20-9 / ISSN 1314-2704, June 19-25, 2014, Book 6, Vol. 1, 3-10 pp

ABSTRACT
A large deformation degree was induced on High Strength Low Alloy steel X60
samples in hot rolled state. The plastic deformation process was conducted on cold rolling mill start to 0.03 up to 3.14 true strain in 43 passes, without intermediate thermal treatments. Also an original severe plastic deformation method – High Speed High Pressure Torsion was applied. The achieved true strain was very similar but had been obtained in one step. Here we report the grain structure evolution from coarse equiaxed grains to fine and ultrafine structure. For cold rolled respectively HSHPT’ed samples was performed a comparison of structures by OM and SEM. However the structure development in each plastic deformation process was strong function of the true strain achieved. Both HS HPT and cold rolling technological parameters were monitored and mechanical properties were determined.

Keywords: Severe plastic deformation, High Speed High Pressure Torsion, High
Strength Low Alloy Steel, ultrafine grain structure, OM, SEM, Microhardness