Shear band formation in IF steel during cold rolling at medium reduction levels

Abstract

The mechanisms of shear band formation in IF steel after cold rolling to $50% reductions have been investigated using transmission electron microscopy. The observations revealed that shear bands were always parallel to a second set of microbands, where these exist, and contained within individual crystals, indicating that shear banding is controlled by orientation. Crystallographic analysis revealed that shear banding involves two mechanisms, dislocation glide and rigid-body rotation. In the first step, dislocation glide causes a rotation about the h211i axis to produce the so called 'S' band, which gives the shear band its crystallographic character. In the second step, when the most heavily stressed slip plane parallel to the shear band is of the form {110}h111i, rigid-body rotation continues about the h211i axis in the sheared zone and, then, a rotation about the transverse direction (TD) is promoted by the geometry of the sample. Using rigidbody matrix theory, the calculated orientations of shear bands are shown to be in agreement with experimental observations. The process outlined is capable of explaining how slip processes in grains that contain microbands, using either {110} or {112} slip planes, can produce crystallographic shear bands.

Unusual Crystallographic Aspects of Microband Boundaries within {111}^|^lt;110^|^gt; Oriented Grains in a Cold Rolled Interstitial Free Steel

“…Several other {112}<111> slip systems were also found to have high Schmid factors (as shown by the values in columns 6 to 8), but none of these show coincidence with microband boundary interfaces. This outcome also matches the finding of Chen et al 9,27) who showed that the {110}<111> slip systems accommodate shear processes in IF steel during low levels of deformation (~10% reduction) at room temperature. The foregoing discussion confirms that high-angle microband features evolve in two stages.…”

A review of metal-ion-flux-controlled growth of metastable TiAlN by HIPIMS/DCMS co-sputtering

“…Adatom residence times are longer on the low-potentialenergy, low-diffusivity 111 surfaces, thus the local 111 epitaxial growth is preserved. 27,30,56 The residual defect concentration, and hence residual stress (-0.9 GPa), is lower under Al + rather than Ar + ion irradiation since Al is primarily incorporated into the lattice of the growing film, whereas Ar resides in interstitial sites.…”

Microstructure and thermoelectric properties of CrN and CrN/Cr2N thin films

“…However, Cr 2 N also shows a relatively low thermal conductivity value with good electrical conductivity and can be further studied for other applications such as diffusion barriers [59] or hard coatings [60].…”