Processing maps and hot workability of Super304H austenitic heat-resistant stainless steel

Hot-compression and hot-tension experiments were conducted on a Gleeble3500 thermal–mechanical simulator, and the microstructure diagram of Super304H austenitic heat-resistant stainless steel as well as its thermoplastic diagram under different deformation conditions was obtained. Based on the dynamic material model theories and Prasad instability criterion, its hot processing maps were developed. The deformation mechanisms of different regions in the maps were analyzed, and corresponding microstructures were investigated. The results show that for Super304H steel, the critical Z value, below which the complete dynamic recrystallization may occur, is about 4.23 × 1020. During the hot tension at 0.1 and 1 s−1, the total elongation and reduction in area increased with the increase of deformation temperature ranging from 800 to 1100 °C. As for the hot working of Super304H austenitic heat-resistant stainless steel, large-strain deformation can be carried out at 1100 °C and at the strain rate above 0.5 s−1.