Abstract
The effects of addition of various alloying elements to a steel having base composition (0.1 C-0.3 Si-1.0 Mn) on the static recrystallization in the austenite range have been studied by a high temperature double tension method.
It was observed that recrystallized grains nucleated at the grain boundaries and that recrystallization time increased linearly with increasing initial grain size. At 900°C, recrystallization after strained to 0.2 by the first tension was retarded by the addition of Si (_??_1.0), Mn (_??_2.5), Ni (_??_1.0), Cr(_??_1.0), Cu (_??_0.3), Nb (_??_0.04), V (_??_0.1) and Mo (_??_0.4). Among them the retardation effect of Nb was remarkable, and this was explained by precipitation of NbC. On the other hand, the role of other elements in the retardation was ascribed to substitutional solid solution effect. In the Nb added steel, the degree of retardation was found to be significantly influenced by the heating history before a double tension test. This can be explained by the difference in the dispersion of NbC precipitates in addition to the initial grain size. The contribution of individual effect of grain size or precipitation on recrystallization was separated in an analytical way. Recrystallization rate increased with increasing C content (0.0020.07), but this was interpretated as due to the indirect effect of initial grain refinement by carbon.
