Effect of Chemical Composition on Recrystallization Behavior and r-value in Ti-added Ultra Low Carbon Sheet Steel

• Published in: ISIJ International Vol. 34; no. 1; pp. 70 - 76
• Main Authors: Yoda, Rika, Tsukatani, Ichiro, Inoue, Tsuyoshi, Saito, Tadashi
• Format: Journal Article
• Language: English
• Published: The Iron and Steel Institute of Japan 1994
• Subjects: nitrogen content; phosphorus content; r-value; recrystallization temperature; solute titanium; sulfur content; Ti-added ultra low carbon steel; TiC precipitates
• ISSN: 0915-1559; 1347-5460
• DOI: 10.2355/isijinternational.34.70

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.