Ultralow-temperature superplasticity of high strength Fe-10Mn-3.5Si steel

Superplastic steels with high elongations above 300% are expected to be used for manufacturing complex-shaped mechanical parts without joining. However, their practical application is difficult due to high energy consumption and surface oxidation caused by a high deformation temperature (>873 K). Here, we propose a new high strength Fe-10Mn-3.5Si steel, which is superplastically deformed at 763 K. This steel exhibits different microstructural and deformation features from previous superplastic steels, such as single phase before deformation, coarse elongated grains, low strain rate sensitivity, and strong texture. The superplasticity of the steel results from both dislocation creep and grain boundary sliding due to dynamic reverse transformation. Because the steel has a low material cost and is produced by conventional rolling, it is suitable for practical application.

Automated summary

The new high-strength Fe-10Mn-3.5Si steel exhibits superplasticity at lower temperatures, showing different microstructural and deformation features compared to previous superplastic steels, and is suitable for practical applications.