INVESTIGATION OF THE ORIENTATION DEPENDENCE OF RECOVERY IN LOW-CARBON STEEL BY USE OF SINGLE ORIENTATION DETERMINATION

Iron poly- and oligocrystals with a carbon mass content of 0.02 % were cold rolled to a technical strain (epsilon = Delta d/d(0)) of 90 % and annealed at 1000 K in a salt bath furnace far 1 to 300 s. The polycrystals had an initial grain size oi about 20 mu m. The oligocrystals consisted of 20-40 grains with a longitudinal extension of 10-20 mm and a transverse extension of 2-6 mm. The microstructure of both types of specimens was investigated by use of optical and scanning electron microscopy. The crystallographic texture was examined by use of X-ray and electron back scattering diffraction. It is shown that both primary recrystallization and recovery considerably depend on the crystal orientation. in the 90 % cold rolled oligocrystals {111}<uvw> and {112}<110> oriented grains recrystallized during annealing. In crystals with {001}<110> orientation, however, primary recrystallization was suppressed. In the polycrystals the latter phenomenon was less pronounced. In these samples it was observed that {001}<110> oriented grains are consumed by growing nuclei stemming from neighbouring crystals.