Martensitic Phase Transformation and Deformation Behavior of Fe–Mn–C–Al Twinning‐Induced Plasticity Steel during High‐Pressure Torsion

Abstract

The transformation between the face centered cubic austenitic and hexagonal close-packed martensitic phases during high-pressure torsion processing was observed in a Fe-Mn-C-Al twinning-induced plasticity steel. This phase transformation was not found in the same material processed by unidirectional compressive and tensile deformation. Initiated by the high-pressure loading, the martensite phase initially increased with torsional strain but diminished subsequently. Texture evolution of the austenitic phase was compared with the ideal texture distribution of face-centered cubic materials after shear deformation.

Formation of epsilon martensite by high-pressure torsion in a TRIP steel

“…A similar trend was also reported in an AISI 304L steel which was cold rolled to form α' phase and then processed by HPT where an ε phase was developed [20]. An ε phase was also reported after HPT processing of an Fe-Mn-C-Al steel but it was formed from austenite in the very early stage of HPT [19].…”

“…Specifically, it was reported that ε hexagonal martensite was formed when the processing was carried out at -196 ºC while only austenite was observed when processing the material at room temperature [15]. It was also reported that the ε martensite formed in an Fe-Mn-C-Al steel processed by HPT from the austenite phase [19]. Finally, it was also reported that a cold rolled 304L stainless steel with an α' martensite microstructure developed ε martensite in HPT processing and the amount of the ε martensite increased with increasing strain and applied pressure [20].…”

“…In this operation, a sample in the shape of a thin disc is compressed between rigid anvils and subjected to torsional straining. Processing by HPT has been used with iron [5,6] and different steels [6][7][8][9][10][11][12][13][14][15][16], including twinning induced plasticity steels [17][18][19] which also exhibit very high uniform elongations at room temperature. A review of these data shows that different effects were reported during the processing of iron and steels by HPT.…”

Hydrostatic Compression Behavior and High-Pressure Stabilized β-Phase in γ-Based Titanium Aluminide Intermetallics

“…In the present study, we investigate the influence of pressure on the formation of the ductile β-phase in γ-based TiAl alloys, which is not only of fundamental interest, but is also most relevant to modelling high-pressure deformation techniques, such as high-pressure torsion, in order to achieve severe plastic deformation [11][12][13][14][15] and high-pressure near-net-shape forging [16][17][18][19]. These deformation processes operate at pressures up to 7 GPa and forces exceeding 1 GN, respectively.…”

Improving Mechanical Properties of a Forged High-Manganese Alloy by Regulating Carbon Content and Carbide Precipitation

“…As a metastable phase, the FCC phase will induce martensitic transformation when subjected to an external load, and the phase transformation can induce plasticity, which is a TRIP effect [13,18]. While maintaining the TRIP effect, twinninginduced plasticity of high-manganese steel will occur, due to the higher Mn content, which is a TWIP effect [8,[19][20][21][22]. The experimental results show that the tensile strength reaches 900 MPa and ductility is increased by about 60% compared with high-strength steel.…”