Study of phase transformations in EN8 steel material using acoustic emission technique

The use of steel has steadily increased in the recent days especially in ship building, automobile industry and in power plants. The microstructure of these steels consists of a variety of different phase and which leads to superior material properties - a combination of high strength with good formability. For the development of such steels research is required to gain more insight into the underlying microstructure and the mechanisms by which it is formed. In the present study experiments are carried out to distinguish different phases using online monitoring technique - Acoustic Emission (AE). The objective of this work is to have a better understanding of the growth mechanism and solid-state phase transformations that can occur in carbon steel (EN8). In view of the fact that AE is an unexplored technique in this kind of steel research, this study also aims to give a good overview of the possibilities and limitations of AE as a real time monitoring technique for the evolution of bainitic and martensite phase transformations. It is found from the experiments that the basic parameters by which the phase transformation can be found out are energy, counts, RMS and amplitude. By analyzing the obtained AE data, it is possible to study the phase transformation behavior of the particular material.