Corrosion wear and electrochemical corrosion behaviors of laser cladded amorphous FeSiB coating in 3.5% NaCl solution

Abstract

An amorphous FeSiB composite coating was fabricated on S355 structural steel using a laser cladding. The morphologies, phases and hardness of obtained coating were analyzed using a field emission scanning electron microscope (FESEM), X–ray diffractometer (XRD), and microhardness tester, respectively. The corrosion wear and electrochemical corrosion behaviors of FeSiB coating in 3.5% NaCl solution were investigated using a wear tester and electrochemical workstation. The results show that the FeSiB coating with the hardness of 601 HV is primarily composed of amorphous and crystal phases of α–Fe(Si) and Fe2B. The average coefficients of friction (COFs) of FeSiB coating at the wear loads of 3, 5 and 7 N loads are 0.888, 0.751, and 0.564, respectively, which deceases with the increase of wear loads; and the corresponding wear rates are 7.60, 8.02 and 10.04 μm3 · N–1 · m–1, respectively. The corrosion potentials of FeSiB coating and substrate are –0.718 and –1.042 V, respectively, exhibiting that the corrosion potential of FeSiB coating shifts positively, its corrosion resistance was higher than that of substrate.