Effect of heating process on the corrosion resistance of zinc iron alloy coatings

Abstract

Abstract In order to determine the influence of process parameters such as the optimal heating method, heating temperature, and time on the corrosion resistance of zinc iron alloy coatings, and to maximize their corrosion resistance while ensuring coating quality, a study was conducted on the influence of heating process on the corrosion resistance of zinc iron alloy coatings. Prepare coatings on steel-based materials using hot dip method, adjust the auxiliary plating and immersion temperatures, and test the corrosion resistance of coatings at different temperatures. After completing the coating preparation, test the corrosion resistance of the coating under two heating processes, namely, heating furnace and laser, as well as the corrosion morphology and corrosion rate of the coating under different heating temperatures. Calculate the corrosion loss of the coating under different heating durations. The experimental results show that the corrosion resistance of the coating is better when the auxiliary plating and immersion temperatures are 70 and 450°C, respectively. When the laser heating process is selected and the heating temperature does not exceed 450°C, the corrosion resistance of the coating is higher. Once the temperature is exceeded, the corrosion resistance of the coating decreases, and with the increase of heating time, the corrosion resistance of the coating will decrease. When the heating time is 14 min, the mass loss of the coating reaches 0.011 g. And in the electrochemical corrosion test, after soaking for 18 days, the polarization resistance value of the zinc iron alloy coating decreased to 987.8 Ω·cm2, achieving complete failure.