Purpose To enhance the corrosion and wear resistance of 3Cr13 stainless steel in seawater by depositing an iron-based composite coating on its surface. Method A high-velocity arc-spraying (HVAS) technique was employed. A flux-cored wire was prepared with 434 stainless steel as the outer sheath and alloy powder (60–80 mesh) as the core filler. The iron-based composite coating was sprayed onto 3Cr13 steel substrates. Surface and cross-sectional morphologies were examined by scanning electron microscopy (SEM), and coating thickness was measured. Hardness was determined with a nano-indenter. Corrosion behavior of both substrate and coating was evaluated in 3.5 wt % NaCl solution using an electrochemical workstation. Tribological performance in 3.5 wt % NaCl solution was tested with a multi-functional tribometer and white-light interferometer; wear tracks were analyzed by SEM and energy-dispersive spectroscopy (EDS). Results Coating thickness was ~385 µm. The microstructure was uniform with well-melted splats, minor phase separation, and a few unmelted particles. Hardness HV0.05 of the iron-based composite coating was ~535. In 3.5 wt % NaCl solution the corrosion potential and current density were –499 mV and 5 µA cm⁻², respectively; corrosion initiated mainly at surface defects. Average steady-state friction coefficients in 3.5 wt % NaCl were 0.590 for the coating and 0.761 for 3Cr13 substrate; corresponding wear rates were 2.04 × 10⁻⁵ and 5.88 × 10⁻⁵ mm³·N⁻¹·m⁻¹. The coating exhibited mild abrasive wear, whereas the substrate showed deep ploughing and more severe abrasive wear. Conclusion High-velocity arc-sprayed iron-based composite coatings significantly improve the wear resistance of 3Cr13 steel in 3.5 wt % NaCl solution, but do not enhance its corrosion resistance.

Key words: High-Velocity Arc Spraying; Iron-Based Composite Coating; Microstructure and Properties