1994 年 34 巻 1 号 p. 70-76
The changes in recrystallization behavior and r-value by reducing impurity elements in Ti-added ultra low carbon sheet steel were investigated. The recrystallization temperature of high-purity steel is lower than that of conventional impure steel when compared at a given finish-rolling temperature or solute titanium content. This is attributed to the retarding effect of phosphorus, which can be interpreted on the basis of a commonly accepted solute-drag effect since sulfur and nitrogen have almost no effect on recrystallization behavior. The half-recrystallization temperature of Ti-added ultra low carbon steel is more closely related to the content of solute titanium, rather than the amount of TiC precipitates. The superior difference of r-value in high-purity steel in comparison to conventional impure steel is assumed to have arisen from the balance between an unfavorable effect, which may be a suppression in grain growth, caused by the increase in sulfur and nitrogen contents, and a favorable effect caused by the addition of phosphorus.
