Document Type : Research Paper
Authors
1 chamran university
2 1 Department of Materials Science and Engineering, Faculty of Engineering, Shahid Chamran University of Ahvaz, Ahvaz, 61357-83151, Iran
3 Department of Materials Science and Engineering, Faculty of Engineering, Shahid Chamran University of Ahvaz, Ahvaz, 61357-83151, Iran
Abstract
In steel production plants, such as those manufacturing sheets, pipes, and round bars, raw materials are annealed in preheating furnaces at approximately 1200 oC before undergoing hot deformation process. Substantial oxidation and loss of raw steel materials occur in preheating furnaces, resulting in significant economic losses. A potential solution to reduce losses in this scenario is the application of protective ceramic coatings. This research investigates the effect of a ceramic coating based on Al2O3-SiO2 on the oxidation behavior of steel sheets. The industrial-scale effect of the coating on the oxidation of steel slabs is also examined. The coating was applied using a spray method with slurry ceramic materials dispersed through a compressed air flow. Thickness measurement tests, scanning electron microscopy, and EDS analysis were conducted to evaluate the kinetics, microstructure and the oxidation behavior of the coatings. The findings indicate that the oxidation kinetics for uncoated steel sheets follow a parabolic trend, while the kinetics for ceramic coated samples exhibit a slower logarithmic behavior. The application of the coating resulted in a reduction of the oxide layer thickness by less than 30% compared to the uncoated samples, attributed to a lower diffusion coefficient in the coated samples. In industrial Test, the application of the ceramic coating on St52 slabs led to a significant reduction in the oxide layer thickness and easier peel of the oxide layers. These show that the use of such ceramic coating for materials in preheating furnaces can effectively reduce oxidation losses and enhance mechanical quality of final products.
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