Effect of Heat Input on Microstructure and Microhardness in WAAM

Experiments were carried out for WAAM of samples using electric arc and additive material in the form of solid wire grade G3Si1. The layers were built-up with one transition each. Metallographic macro- and microsections were made from the obtained samples. The macro- sections are used to determine the locations of microhardness measurements. The microsections were used to measure the microhardness and to illustrate the microstructure. The analysis of the obtained results shows that the heat input and the interlayer temperature are of crucial importance for the obtained mechanical characteristics of the built-up samples. The microstructure of the obtained layers varies along the height of the built-up samples thus witnessing for the thermal treatment occurring in each layer except the last one as a result of applying the subsequent layers.