Wear resistance study on HVOF based SiC and TiB2 ceramic coating for AH36 steel for marine based thermal applications

Abstract

ASTM AH36 steel has been a primary material used for marine-based construction and applications. It is also a primary material employed in boilers and thermal-based equipment. The material is known for versatility and reliability in marine environments. However, the steel has an inherent limitation for wear resistance when subjected to adverse conditions during operation by the marine ecology as well as abrasive materials when being in thermal operation. This has been a major reason for services and these problems can be mitigated by improving the hardness, chemical inertness and adhesion to the substrate. Silicon Carbide (SiC) and Titanium Diboride (TiB2) are noted for their hardness and ecologically inert behaviour. The steel surface has been coated with these ceramic materials to improve the wear resistance. The coating is provided by the High-Velocity Oxy-Fuel (HVOF) technique. A microstructural, mechanical and wear analysis is performed on SiC, TiB2 and Mixture of 80 %SiC-20 %TiB2 coated specimens to analyze the surface modifications. Based on the pin on disc test results it can be observed that the application of Silicon Carbide and Titanium Diboride coatings has shown an improvement in wear resistance by reducing a wear loss by 1/8th, 1/6th and 1/10th respectively against the uncoated specimen. This increase in wear resistance is attributed to the improvement in the hardness of the surface by formation of harder compounds and additional phases during HVOF process. This indicates that inert material-based surface modifications can be an ecofriendly and effective way to improve the wear resistance in marine steels.