: Because it shares the BCC structure with alpha iron, it possesses similar mechanical properties, though it is slightly less dense due to thermal expansion at higher temperatures. Technical Comparison of Iron Phases Common Name Crystal Structure Magnetic State Temperature Range Alpha ( ) Ferromagnetic Beta ( ) Beta Iron BCC Paramagnetic Gamma ( ) Non-magnetic Delta ( ) Delta Ferrite Non-magnetic (PDF) The Beta Iron Controversy Revisited - ResearchGate

, it undergoes a true allotropic transformation into Austenite ( ), which has a Face-Centered Cubic (FCC) structure.

). Historically considered a distinct allotrope, it is now primarily viewed as the high-temperature, paramagnetic form of ferrite. Key Features and Characteristics While it was once debated whether

: Most contemporary iron-carbon phase diagrams omit the "beta" label because it is not a crystallographically unique phase; the entire BCC region is typically just labeled as