Comparative Study into Microstructural and Mechanical Characterization of HVOF-WC-Based Coatings

Abstract

The main objective of this work was to characterize and compare the microstructural and mechanical properties as well as erosion resistance of WC-12Co and WC-10Co-4Cr coatings. The High Velocity Oxy Fuel (HVOF) process was applied to carbon manganese steel API 2H typically used in oil and gas industries. Microstructural characterization of feedstock powder and coatings was conducted using scanning electron microscope (SEM), energy dispersive X-ray spectroscopic (EDS) analysis, X-ray diffraction (XRD) for phase determination, powder particle size distribution, and surface roughness measurement. The average particle size of the former powder was 13.7 µm whereas it was 28.1 µm for the latter. The results showed that the smaller particle size tends to melt easier than the larger one, as deduced from SEM images and surface roughness measurements. EDS and XRD results of both coatings indicated the occurrence of WC decomposition where the powder particle size plays a significant role in these results. Mechanical characterization was discussed through comparing hardness, erosion, and adhesion test results of both coatings. WC-10Co-4Cr coating exhibited higher hardness than WC-12Co as well as higher erosion resistance, due to the extent of decomposition of WC and also to carbide particle size within the coating layer; these are the same reasons for the superior adhesion strength of the former coating compared to the latter one as per ASTM Standard “C633- 13”.

The Effect of Zirconia Nanoparticles on Thermal, Mechanical, and Corrosion Behavior of Nanocomposite Epoxy Coatings on Steel Substrates

“…The EIS method has been reported as a powerful technique in studying the prevention of corrosion using coatings [ 23 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ]. We have employed EIS to report the performance of the fabricated coatings against corrosion after various exposure times in NaCl electrolytes.…”

“…The EIS method has been reported as a powerful technique in studying the prevention of corrosion using coatings [23,[26][27][28][29][30][31][32]. We have employed EIS to report the performance of the fabricated coatings against corrosion after various exposure times in NaCl electrolytes Figure 6 shows the Nyquist plots for the coated steel samples (EZr-1, EZr-2, and EZr-3 after their exposure in 3.5% NaCl for 1 d before measurement.…”

Application of Hvof Technology for Wc-Based Wear-Resistant Coatings – An Overview

“…Все виды технологии HVOF в вышеуказанных компаниях используют единый принцип создания сверхзвуковых течений газового пламени и имеют только конструктивные особенности, в основном, связанные с получением разной скорости и температуры газопорошковой смеси, условиями охлаждения, отличающиеся производительностью напыления. Технология HVOF в основном напыляет материалы, на основе карбидов, обладающих высокими эксплуатационными характеристиками, такие как высокая стойкость к абразивному, эрозионному и кавитационному износу [26][27][28]. Благодаря таким характери-стикам карбидосодержающие композиты хорошо зарекомендовали себя как износо-и эрозионно-стойкие покрытия во многих отраслях промышленности, таких как аэрокосмическая и морская (шасси самолетов, пропеллеры, газовые турбины, гидравлические приводы), бурение нефтяных и газовых скважин, резка металла, горнодобывающая промышленность, обработка металлов давлением, целлюлозно-бумажная промышленность, геотермальная энергетика, производство электроэнергии (газовые турбины) и морские сооружения [29][30][31].…”