Precipitation in Cu-Bearing GOES at the Start of Primary Recrystallization

The role of copper additions to GOES has not been fully understood yet. Several mechanisms have been proposed: stabilization of austenite during hot rolling in two phase α+γ region, precipitation of e - Cu, dissolution and re-precipitation of Cu-bearing sulfides, segregation of copper at grain boundaries and support of deformation by twinning and shear during cold rolling.This paper deals with minor phase evaluation in Cu–bearing GOES after following manufacturing steps: a) the first cold rolling and decarburization annealing at 820 °C, b) the second cold rolling followed by a slow laboratory heating to the temperature of primary recrystallization (620°C). Microstructure analysis was carried out using EBSD and TEM techniques. Results of experimental studies were compared with Thermocalc predictions of the copper effect on equilibrium phases in GOES.