Surface morphology and grain size of 45 steel after scanning by electron beam

摘要

The modification of 45 steel surface by continuous scanning beam process (CSEBP) in the regimes being different in the scanning frequencies (f = 300, 400, 500, 600 Hz) were performed in the research. The results show that when f is 500 Hz, the surface roughness is reduced to 0.48 mu m, which is about 85%. The original scratches are still visible when f is low, the surface is overheated and volcanic craters are easy to appear when f is too high. The surface grains are refined when CSEBP treatment. The grains are mostly equiaxed and the size is mainly between 5 and 25 mu m. Under non-equilibrium solidification, parallel dendrites with a size of 300-800 nm are formed in the grains. (C) 2021 Published by Elsevier B.V.