DEVELOPMENTS IN MACRO AND MICRO TEXTURE DURING PLANE-STRAIN CHANNEL DIE COMPRESSION OF IF STEEL

Textural developments in plane strain channel die compressed IF (inter stitial free) steel were investigated for 7-75% reduction in thickness . Developments in macro texture were investigated by X-ray ODFs (orien tation distribution functions) and were simulated by Taylor type model s, while actual microtextural developments were studied by OIM (orient ation imaging microscopy). Although a gradual increase in or-fiber (RD //[110]) was observed with increased reductions, gamma-fiber (ND//[111 ]) increased till 40-50% reduction and then remained almost the same. At the earlier stages of deformation and in general for relatively lar ger grains, areas around grain boundaries were relatively more deforme d (ie. with more frequent low angle boundaries) and more rotated (as t ested in split samples at 7 and 18% reduction) than the grain interior . Till 50% reduction, deformation substructures among deformed grains of different orientations were not significantly different. Above 50% deformation, relatively intense strain localizations (in the form of h igher frequencies and larger misorientations of grain boundaries) were observed to form at an angle of about approximate to 37 degrees with RD (rolling direction), somewhat more preferentially in the gamma-fibe r deformed grains of F {111}[112] and E {111}[110] components. The app earance of such strain localizations increased the stored energies of F/E bands and also possibly accounted for the formation of new high an gle boundaries (as evident from increased grain splitting factors).