Abstracts Book - IMRC 2018

• SD3-O013
MICROSTRUCTURAL EVOLUTION IN SEVERELY DRAWN HIGH
CARBON CONTENT WIRES
Martina Cecilia Avalos 1 , Elena Brandaleze 2 , Mykhaylo Romanyuk 3 , Raul Eduardo Bolmaro 4
1 Instituto de Fisica Rosario, Electron Microscopy Lab, Argentina. 2 Universidad Tecnológica
Nacional- Facultad Regional San Nicolás, Departamento Metalurgia- Centro DEYTEMA,
Argentina. 3 Universidad Tecnológica Nacional, Departamento Metalurgia- Centro DEYTEMA,
Argentina. 4 Instituto de Fisica Rosario, Micromecanica de Materiales Heterogéneos, Argentina.
Severe Plastic Deformation can induce nanometric grain sizes, phase
distributions and defect storage that cannot be achieved by any other means.
Their microstructures are responsible for mechanical property improvements
which have not been fully exploited yet except for a few cases. High carbon
content steels subject to large wire drawing deformation, and later on bundled
together forming conforming large section cables, are one of the few products
of extensive large scale application. They develop high strength (5-6 GPa) and
large ductility, making them particularly useful for applications such as cables
for bridges and heavy cranes. The technology is well known but the complex
interaction between deformation mechanisms, microstructure development
and precipitates due to the high carbon content (~0.84%) has not been
completely clarified. Clarification of those mechanisms in such successful
product may shed light on modern SPD processes.
In this work we present EBSD results in high carbon content wires of several
diameters (8 mm, 7 mm, 3.2 mm, 2.8 mm, 2 mm). Optical and EBSD microscopy,
together with XRD, were used to characterize textures, microtextures and
microstructure evolution. Differential Thermal Analysis (DTA) and
thermodynamic simulations (FactSage) were used to characterize their thermal
responses.
Inverse Pole Figure maps, misorientation distribution parameters (KAM, GAM,
GOS, GND, etc.) and other post-processing tools are used for characterizing the
evolution of the microstructure. Some other test like micro-hardness and
mechanical torsion tests were correlated with the microstructure evolution.
Despite being subject to room temperature deformation, the severity promotes
several dynamic recrystalization and strain aging mechanisms like cementite
destabilization and carbon diffusion with a consequent increase on the material
strength [1,2]