Abstract

Although precipitates in IF steels have been observed by many authors, they have yet to appear in stress vs. strain curves during laboratory simulations. The flow behavior of an IF steel was investigated during multi-pass deformatíón under conditions similar to those of a hot stríp mill by means of torsión tests. With short interpass times, there was a sharp and unexpected increase in the level of flow stress as the material was strained at temperatures of around 920°C, suggesting the presence of a hardening mechanism operating during the arrest time. TEM and X-ray chemical microanalysis techniques revealed the presence of precipítales such as TiS and TL4C2S2 (transformed in situ and finely precipitated) in samples quenched after si raining.