Open AccessResearch on the Influence of Different Paint Film Thickness Combination on Corrosion Resistance of Sandblasting Steel Plate
Author(s) -
Zhang Huayuan,
Bing Xue,
Can Wang,
Yongyong Yue,
Jing Luo,
Ran Yan
Publication year - 2021
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1965/1/012106
Subject(s) - materials science , corrosion , carbon steel , composite material , metallurgy , polarization (electrochemistry) , salt spray test , scanning electron microscope , primer (cosmetics) , chemistry , organic chemistry
To guide the selection of paint film thickness scheme with high cost performance when spraying sandblasting steel plate. In this paper, we sprayed different film thickness with the combination of primer and topcoat on the sandblasting steel plate. The corrosion resistance was evaluated by neutral salt spray test and electrochemical test of different film thickness combinations. In addition, the corrosion morphology was analyzed by automatic inverted metallographic microscope. Furthermore, potentiodynamic polarization and electrochemical impedance (EIS) curves were used to analyze the corrosion mechanism. The self-corrosive current density (I corr ) is 1.999 × 10 -12 A·cm -2 with the combination of primer and topcoat thickness (20 μm+20 μm) and the self-corrosive current density (I corr ) of low carbon steel matrix is 1.855 × 10 -5 A·cm -2 from the analysis of polarization curves from kinetic potential. The impedance value on 0.01 Hz (|Z| 0.01Hz ) (4.56 × 10 10 Ω·cm 2 ) of the combination of primer and topcoat thickness (20 μm+20 μm) after immersing in 3.5 wt. % NaCl for 2 hours was more than eight orders of magnitude higher than the value (|Z| 0.01Hz 6.52 × 10 2 Ω·cm 2 ) of the low carbon steel plate after immersing for 0.5 hours. Even dipping in 3.5 wt. % NaCl for 168 hours, the |Z| 0.01Hz value of the combination of primer and topcoat thickness (20 μm+20 μm) was still three order of magnitude higher than the low carbon steel plate with 0.5 hours immersion. Increasing the film thickness of the topcoat can improve the anticorrosion performance under the condition of a certain thickness of the primer. However, too thick coating will generally bring greater internal stress, which leads to the cracking of the coating in the process of use because of the change of external force and temperature, thus affecting the anticorrosion performance. When the total film thickness is certain, with the increase of the proportion of primer increase of the proportion of primer film.