  The inner structure of a material is called microstructure. It stores the
genesis of a material and determines all its physical and chemical properties.
While microstructural characterization is widely spread and well known, the
microstructural classification is mostly done manually by human experts, which
gives rise to uncertainties due to subjectivity. Since the microstructure could
be a combination of different phases or constituents with complex substructures
its automatic classification is very challenging and only a few prior studies
exist. Prior works focused on designed and engineered features by experts and
classified microstructures separately from the feature extraction step.
Recently, Deep Learning methods have shown strong performance in vision
applications by learning the features from data together with the
classification step. In this work, we propose a Deep Learning method for
microstructural classification in the examples of certain microstructural
constituents of low carbon steel. This novel method employs pixel-wise
segmentation via Fully Convolutional Neural Networks (FCNN) accompanied by a
max-voting scheme. Our system achieves 93.94% classification accuracy,
drastically outperforming the state-of-the-art method of 48.89% accuracy.
Beyond the strong performance of our method, this line of research offers a
more robust and first of all objective way for the difficult task of steel
quality appreciation.
