Steel is considered the most widely used metal because of its excellent strength and comparatively low-production cost. Preventing steel corrosion will be a top priority in industry. This work investigates the influence of an epoxy resin liner to steel filled with different percentages (1, 2, and 3 wt%) of either micro or nanoparticles of alumina (Al2O3) on both bending properties and corrosion resistance. To test for barrier resistance, the coated steel samples were submerged in a citric acid and saline solution. In comparison with pure epoxy coatings, the addition of nano and micro alumina (Al2O3) particles enhanced the corrosion resistance, bending strength, and bending strain under dry and wet conditions. Furthermore, under both dry and wet circumstances, the bending strain rose dramatically with the addition of micro and nano fillers. The 1 wt% of Al2O3 nanoparticles coated steel exhibited the maximum bending strength of 492.81 and 436.9 MPa under wet and dry conditions, respectively. Moreover, the micro filled steel of 1 wt% Al2O3 micro fillers exhibited a 483.7 and 319.08 MPa bending strength under wet and dry circumstances, respectively. Stepwise graded micro/nanocomposite coatings showed good bending and corrosion properties in both dry and wet conditions.