Phase transformation induced by severe plastic deformation in the AISI 304L stainless steel

The phase transformation caused by high pressure torsion (HPT) of a cold rolled AISI 304L stainless steel was investigated. After cold rolling the steel has a microstructure of martensite α′ (bcc) with a magnetization saturation of 136.0 A m−2 kg−1. The HPT processing with pressures of 2 and 5 GPa promoted the α′ (bcc)→ε (hcp) partial transformation, as observed by X-ray diffraction. The magnetization saturation decreased by the increase of true deformation by HPT, which is in agreement to the α′ decrease.