Influence of state of Nb on recrystallization temperature during annealing in cold-rolled low-carbon steels

The influence of state of Nb on recrystallization temperature during annealing in cold-rolled low-carbon steels was investigated. Two kinds of specimens showing a remarkable difference in recrystallization temperature were prepared. Differences in the features of Nb-containing precipitates larger than 3 nm were rarely observed, whereas differences in precipitates smaller than 3 nm were confirmed by atom-probe field-ion microscopy in each hot-rolled sheet. The difference in the recrystallization temperatures of both specimens probably originates in the state of Nb at the atomic scale before annealing.