Compositionally graded steels: a strategy for materials development

A study was conducted to demonstrate that the the strategy of combining microstructural design and the spatial distribution of composition provided a powerful tool for combining strength and ductility of structural steels. This strategy represented the first step in building a hierarchy of architectures, which were realized with a very simple and cost-effective process, such as the localized addition or removal of carbon through carburizing or decarburizing atmospheres. A prototype requirement, including the combination of high strength and good formability was used to demonstrate the approach. The study approximated the elastoplastic behavior of the two phases as a bilinear behavior and assumed that both phases had similar Young moduli to simplify the approach.