Microhardness profile prediction of a graded steel by strain gradient plasticity theory

In the present study, the Vickers microhardness profile of functionally graded steel austenitic steel produced by electroslag remelting process has been investigated. To produce functionally graded steels, two different slices from plain carbon steel and austenitic stainless steels were spot welded and used as electroslag remelting electrode. Functionally graded steel containing graded layers of austenite may be fabricated via diffusion of alloying elements during remelting stage. Vickers microhardness profile of the specimen has been obtained experimentally and modeled with mechanism-based strain gradient plasticity theory. In this regard, the density of the statistically stored dislocations and that of geometrically necessary dislocations was related to the Vickers microhardness profile of each layer. The experimental results are in good agreement with those obtained from the theory.