Determination of no-recrystallization temperature for a Nb-bearing steel

The recrystallization behavior of a Nb-bearing steel was investigated during multipass deformation under continuous cooling conditions. By a series of six-pass compression tests conducted on a thermomechanical simulator, the effect of deformation parameters, including strain, strain rate and interpass time, on the no-recrystallization temperature (Tnr) was determined. The results show that Tnr decreases with increasing strain and also decreases slightly with increasing strain rate. The strain has more appreciable influence on the Tnr compared with strain rate. When the interpass time is less than 10 s, the Tnr decreases with increasing interpass time. The mathematical model of Tnr was established considering the effect of pass strain, strain rate and interpass time. The calculated results agreed well with the actual experimental value.