Oxidation resistance of Al 2 O 3 /SiO 2 nanocomposite coating on hot-dip galvanized steel deposited by chemical immersion and sol-gel coating
Journal
Surface and Coatings Technology
Journal Volume
404
Date Issued
2020
Author(s)
Abstract
A protective coating against oxidation of hot-dip galvanized (HDG) steel was developed using a solution-based route and its oxidation protectiveness during hot-stamping was evaluated. An Al2O3/SiO2 nanocomposite coating of approximately 500 to 700 nm was developed and successfully processed on a HDG SGC400 steel via a chemical immersion and sol-gel dip coating method. Oxidation tests at 900 °C show that oxidation of the HDG SGC400 steel is effectively suppressed by the Al2O3/SiO2 nanocomposite coating, signifying its potential as a protective coating for HDG press hardening steel. The phase transformation of Al2O3/SiO2 nanocomposite coating at 900 °C was also investigated. Although cracks form inevitably, the Al2O3/SiO2 nanocomposite coating is stable at 900 °C. Specially, the thickness of the composite coating changes slightly and ZnO is confined in the composite coating via the formation of Zn2SiO4 nanoparticles. Finally, this chemical immersion and dipping route to form a nanocomposite oxide coating is in line with the continuous hot-dip galvanizing line for steel industry.
SDGs
Type
journal article