Investigation using neutron diffraction of changes of deformation texture in low carbon cold rolled steel during recrystallisation annealing

Abstract

In many instances the use of neutrons for texture investigation offers advantages over well established X-ray methods, particularly when it is important to have the information averaged over the entire volume of the bulk sample or when it is necessary to obtain this information in a relatively short time. A neutron diffraction technique for texture investigation in low carbon cold rolled steel at ambient and elevated temperatures up to 700°C has been established. The use of the high intensity neutron beam from the ISIS pulsed neutron source and the application of the time-of-flight method made it possible to carry out in situ observations of texture formation during recrystallisation annealing. Pole density values were calculated from the integrated intensities of the diffraction spectra including values obtained for peaks at smaller d spacings than are observable with conventional X-ray machines or reactor based neutron instruments. Diffraction peak profile refinement enabled calculations of the line broadening, microstrains, and the elastic stored energies in various texture components to be made. In situ recrystallisation annealing was carried out at two mean heating rates: low (35 K h−l) and high (650 K h−l). Data obtained from in situ experiments give more reliable information and hence a better understanding of the recrystallisation kinetics in various texture components than is obtainable using 'off line' annealing.MST/959