Stability investigation of electrodeposited zirconium diboride ceramic coatings in molten zinc

Abstract

ZrB2 coating was synthesized by molten salt electrodeposition and its stability in molten zinc at 550 °C was investigated by static immersion tests. Macro morphologies, microstructures, phase and chemical composition of the uncoated and ZrB2‐coated 201 stainless steels after immersion in molten zinc for different periods were analyzed to evaluate their corrosion resistance. The results indicated that bare substrate suffered severe corrosion after several hours immersion in molten zinc and the corrosive products were composed of inner δ phase (Fe, Cr)Zn7 and outer ζ phase (Fe, Cr)Zn13. As a contrast, ZrB2 coating acted as an effective barrier against the invasion of molten zinc and greatly improved the corrosion resistance of the substrate materials. The results may provide a potential way to design ZrB2‐based ceramic coatings for corrosion protection in molten zinc environment.

Al2O3 Coatings for Protection of Stainless Steel 316L against Corrosion in Zn-Al and Zn-Al-Mg

“…The accumulation of these reaction products led to the generation of stresses, and the coating was forced to detach, as illustrated in Figure 6d. This potential failure mechanism was observed in other studies investigating the performance of ceramic coatings in liquid Zn [15]. It was previously shown that the Al 2 O 3 coatings remained inert in liquid Zn-Al and shielded SS 316L from the attack of molten metal until coating breakdown occurred.…”

“…Material characterisation of the coatings after exposure to molten metal at high temperatures has identified the presence of cracks that developed in the ceramic coating. The formation of cracks in ceramic and cermet coatings after exposure to high temperatures was reported in other studies in the literature [12,15,31,32]. In addition to this, cracking was linked to stress generated between materials with dissimilar CTE values [18,33].…”

“…Coatings 2024, 14, x FOR PEER REVIEW 11 of 13 coatings in liquid Zn [15]. It was previously shown that the Al2O3 coatings remained inert in liquid Zn-Al and shielded SS 316L from the attack of molten metal until coating breakdown occurred.…”

“…However, the matrix supporting the WC particles was observed to react with liquid Zn alloy, leading to cracking of the WC particles and failure of the coating [4,10]. Ceramic materials show promise due to their inertness in molten metal [11][12][13][14][15]. For example, recent research showed that aluminium oxide (Al 2 O 3 ) is inert to liquid Zn-Al [11].…”

Study on the Zinc Corrosion Resistance and Failure Mechanism of Cobalt-Based Carbide Coatings

“…When used in the galvanized production line, the coating is prone to cracking and flaking under the thermal fatigue load generated by temperature changes and loses its protective effect. 6 Metal-ceramic composite coatings can provide effective protection for the base metal. 7 For example, WC-Ni [8][9][10] and WC-Co [11][12][13][14][15] coatings can provide protection for the base metal, where the high hardness of the tungsten carbide enables the coating to withstand the wear of steel strips in motion.…”