Abstract
The present paper presents the results of a study on the effect of cold deformation upon isothermal aging in S32654 and S31254 superaustenitic stainless steels. Samples were cold rolled up to 60% and aged within the temperature range of 650-950°C for time up to 120 h. Several precipitate species were identified following aging of the steels, with sigma σ phase being the predominant one. The present study helped clarify the effect of cold deformation on the precipitation sequences for both superaustenitic stainless steel grades studied. Cold rolling was found to accelerate precipitation, which occurred during subsequent isothermal exposure. The amount, shape and spatial distribution of all precipitates is an important factor that in general results to higher hardness values, found to be enhanced by prior cold deformation. Finally, the experiments performed indicate a number of phase transformations to precipitation sequences of intermetallic phases taking place, clearly specifying a time-temperature transformation regime where care must be taken during the use of these steels.