Comparative study of steel alloys using STM and XRD

The STM (Scanning Tunneling Microscope) has been used for characterizing the microstructure of various steel samples by utilizing its surface imaging properties. The subgrain sizes of 15 different samples of steel (in the range 20 nm to 250 nm) were studied by the STM and compared with the results obtained using X-ray diffraction (XRD) by employing line profile analysis of the Bragg peaks. Good agreement was observed between the two sets of data of subgrain sizes. This work establishes STM as a useful characterization tool for studies in metallurgy and metal physics.