Microstructural characterization of a warm-deformed microalloyed steel

Journal Article · Tue Apr 15 04:00:00 EDT 2008 · Materials Characterization

DOI:https://doi.org/10.1016/j.matchar.2007.07.012· OSTI ID:21062218

A warm deformation process using torsion testing was carried out on a low carbon Nb-microalloyed steel. The physical processes that occur during deformation were studied by analyzing the warm flow curves. The mechanisms of fine ferrite grain formation were studied by means of optical microscopy and an electron back-scattering diffraction technique. The results show that warm flow curves of ferrite are similar to those affected only by dynamic softening events. Microstructural analysis shows that, with increasing strain, the new fine equiaxed ferrite grains surrounded by high-angle boundaries are generated at the initial boundaries. During the early stages of deformation, as strain increases the grain size decreases and the grain aspect ratio rapidly increases. A further increase of the strain also leads to continuous decreases of both the grain size and the grain aspect ratio. The dynamic softening mechanism and dynamical formation of new fine grains, observed during warm deformation, were verified to be due to continuous dynamic recrystallization.

• OSTI ID: 21062218
• Journal Information: Materials Characterization, Journal Name: Materials Characterization Journal Issue: 4 Vol. 59; ISSN 1044-5803; ISSN MACHEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ASPECT RATIO
BACKSCATTERING
DEFORMATION
ELECTRON DIFFRACTION
FERRITE
GRAIN SIZE
LOW ALLOY STEELS
OPTICAL MICROSCOPY
RECRYSTALLIZATION
STRAINS