Experimental Study on Neutral Salt Spray Accelerated Corrosion of Metal Protective Coatings for Power-Transmission and Transformation Equipment

Abstract

At present, the common protection technology of power-transmission and transformation equipment is mainly coating protection and hot-dip zinc protection. However, due to the low adhesion of epoxy zinc-rich coating, and the poor compatibility with top paint, environmental pollution, complex processing, high energy consumption and other defects of the hot-dip zinc process, its development is limited. In view of the above deficiencies, new anti-corrosion coating materials and processes were investigated in this study. Zinc coatings and Al-Zn coatings were prepared on the C45 steel matrix by hot-spraying and cold-spraying processes. The macro appearance, micromorphology and phase composition analysis of the coatings were evaluated. The adhesion of the coating to the substrate after the salt-spray test was tested. The results showed that the hot dip zinc coating and hot spray zinc coating had obvious cracking after the salt-spray test. The surface structure of cold-sprayed Al-Zn coating was relatively dense after the salt-spray test. The critical load of the cold-sprayed Al-Zn coating after the salt-spray test was higher than that of the other two coatings. The corrosion resistance to salt spray of cold-sprayed Al-Zn coating was demonstrated to be better than the hot-dip zinc coating, and thus has great application prospects.

Physical and Chemical Properties of High-Temperature Silicone-Based Polymer Coatings Applied on Different Surface Roughnesses

“…Adhesion performance is one of the most important properties of protective coatings [29]. The greater the adhesion between the coating and the substrate, the better the coating protection performance, which improves the corrosion resistance of the coating and prolongs the service life of the coating [14]. The results showed that sandblasted samples have better adhesion.…”

“…Authors [12,13] used electrochemical impedance spectroscopy (EIS) as a method to evaluate the condition of the coating surface and its barrier properties, which are key to achieving satisfactory corrosion resistance of the coating. Chen et al [14] used a neutral salt spray test to accelerate the indoor aging of cold-spray aluminum zinc, hot-spray zinc, and hot-dip zinc coatings. After the salt spray test adhesion was determined by the method of a scratch test.…”