|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Multiscale Architectured Materials (MAM II): Tailoring Mechanical Incompatibility for Superior Properties
||Superior Combinations of High Strength and Ductility in Compositionally Graded Martensitic Steels
||Hatem S. Zurob, Hamid Azizi, Olivier Bouaziz, David Embury
|On-Site Speaker (Planned)
||Hatem S. Zurob
Steels with more than 0.3 wt%C offer strength levels in excess of 2 GPa, but suffer from very limited ductility. Controlled decarburization of medium carbon steels can be utilized to produce architectured structures with unique combinations of strength and ductility. The improved ductility is attributed to the presence of low carbon martensite at the surface which serves to arrest surface cracks and prevent the propagation of shear bands which are formed within the high carbon core. These graded materials can be cold-rolled and annealed to produce a bimodal microstructure containing a mixture of nanoscale and microscale ferrite grains. This microstructure combines high yield strength and reasonable work-hardening. The heterogeneity of the graded microstructures can be varied by changing the decarburizing parameters. The application of multiple carburizing/decarburizing steps along with diffusion barriers can be used to introduce an additional degree of heterogeneity along the length and width of the material.