1) 20 Marks The microstructure of a mild steel component is to be examined by optical microscopy and scanning electron microscopy (SEM). a) List and briefly describe the main processing steps that would be involved in the preparation of a metallographic sample from the mild steel component suitable for examination by optical and SEM. For each step, list any typical equipment used. (15 Marks) b) As shown in the SEM images to the right (obtained from different metallographic samples of the same steel component), the steel has a microstructure consisting of alternating "lamellae" (or "layers") of ferrite (light) and cementite (dark). Image (a) shows lamellae which are relatively straight and parallel whereas the image (b) shows significant bending of the lamellae. Given that Image (a) is representative of the real structure of the steel, whereas the bending of the lamellae in Image (b) is not, explain a feasible reason for the occurrence of the latter and propose what could be done in practice to avoid it. (5 Marks) (