Neural Networks to Predict Impact Energy of Functionally Graded Steels: Experimental Study

Charpy impact energy of functionally graded steel produced by electroslag remelting has been modeled in crack divider configuration. To produce functionally graded steels, two slices of plain carbon steel and austenitic stainless steels were spot welded and used as electroslag remelting electrode. Functionally graded steel containing graded layers of ferrite and 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 artificial neural networks. To build the model for graded ferritic and austenitic steels, training, testing and validation using respectively 174 and 120 experimental data were conducted. The Vickers microhardness of each layer in functionally graded steels was related to the yield stress of the corresponding layer and by assuming Holloman relation for stress-strain curve of each layer, they were acquired. Afterwards; the stress-strain curves were modified by the load-displacement data achieved from instrumented Charpy impact tests. Finally, by applying the rule of mixtures, Charpy impact energy of functionally graded steels in crack divider co