Microstructure, Mechanical Properties, Abrasive Wear, and Corrosion Behavior in Molten Zinc of Boride-Based Coatings in Situ Synthesized by an HVOF Spraying Process

Coatings

Hongtao Wang¹  Su Song¹  Xiaobo Bai²  Shunjian Xu²  Chengdi Li³  Xiao Chen³ 

[1] Remanufacturing, School of Mechanical and Materials Engineering, Jiujiang University, Jiujiang 332005, China;;Jiangxi Province Engineering Research Center of Materials Surface Enhancing &Xinyu Key Laboratory of Materials Technology and Application for Intelligent Manufacturing, School of Mechanical and Electrical Engineering, XinYu University, Xinyu 338004, China;

关键词: high velocity oxygen-fuel;    boride;    microstructure;    microhardness;    abrasive wear;    corrosion resistance;   

DOI  :  10.3390/coatings9100665

来源: DOAJ

【 摘 要 】

Hot-dip galvanizing has been used for anti-corrosion of various steel products; however, the corrosion of molten zinc in the galvanizing industry is the key problem to be solved. Three kinds of Mo−B−Co−Cr, Mo−B−Ni−Cr, and Ti−B−Co−Cr mixture powders were deposited on the surface of a 316L stainless-steel substrate by a HVOF spraying method to prepare MoB/CoCr, MoB/NiCr, and TiB/CoCr coatings. The microstructure, mechanical properties, abrasive wear, and corrosion behavior in molten zinc of the in situ synthesized boride-based coatings were investigated. The experimental results showed that MoB/NiCr coating with a denser microstructure had the lowest porosity (0.811%). The in situ synthesized boride-phase compositions of MoB/CoCr, MoB/NiCr, and TiB/CoCr coatings were CoMoB and CoMo₂B₂, NiMo₂B₂, and TiB₂, respectively. The MoB/NiCr coating had the highest boride content among the coatings. The presence of binary (TiB₂) or ternary boride phases (CoMoB, CoMo₂B₂, and NiMo₂B₂) with their excellent mechanical properties could obviously increase the microhardness values in the coatings. The in situ synthesized borides in the coatings also could improve the wear resistance properties; MoB/NiCr coating with shallower grooves and smaller craters/pits had the smoothest worn surface and the lowest weight loss (6.8 ± 0.84 mg) among the coatings. After immersion test in molten zinc for 360 h, no presence of zinc or intermetallic compounds in the three kinds of the coatings (MoB/CoCr, MoB/NiCr, and TiB/CoCr), and the element compositions of the three kinds of coatings after the immersion test were the same as the as-sprayed coatings. Compared to the other coatings, MoB/NiCr coatings had the higher durability in molten zinc.

【 授权许可】

Unknown