|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Advanced Characterization Techniques for Quantifying and Modeling Deformation
||Unexpected Stress Induced Martensite Formation in Ultra-strong Pearlitic Steel
||Soundes Djaziri, Yujiao Li, Shoji Goto, Dierk Raabe, Gerhard Dehm
|On-Site Speaker (Planned)
The overview presents the microstructure evolution of severely wire drawn pearlitic steel unravelled by combining TEM/STEM, XRD methods, and atom probe tomography. When subjecting pearlite to heavy wire drawing, the material is rendered nanostructured reaching an exceptional strength of as a high as 7 GPa, which makes it one of the strongest known materials. More specific, the high strength is attributed to strain-driven fragmentation and dissolution of the cementite phase which leads to a refined nanostructured composite material. So far the underlying microstructure mechanisms are only partly understood. Especially, the accommodation of carbon in ferrite stemming from the cementite dissolution process remained unclear. Based on our results we find that the carbon supersaturation of ferrite induces martensite formation. This is surprising, as martensite is believed to form only by rapid quenching of steel from the high temperature austenite field. Therefore, we propose that cold drawing can induce a martensitic transformation.
||Planned: EPD Congress Volume