The erosion-corrosion rules and synergistic mechanism of the AC-HVAF sprayed Fe-based amorphous metallic and WC-10Co-4Cr cermet coatings in hydraulic fracturing fluid were studied by jet impingement and electrochemical testing methods.The leading role of the corrosion resistance and hardness during the erosion-corrosion was determined.The results show that the hardness of materials has a significant impact on the erosion-corrosion behavior of the coatings,and the WC coating with higher hardness exhibits high erosion-corrosion resistance.The interactions of erosion and corrosion are determined,and the dominant role of the coatings is the damage caused by mechanical factors.The damage caused by corrosion factors forms a large proportion of the coatings.Improving the corrosion resistance of the coating can reduce the loss of interaction,and then improve the erosion resistance.The coatings exhibit brittle erosion process,and mainly reflect in the crash and cutting erosion of the hard particles.The decrease of the porosity and increase of the combining bonding strength are the key factor to increase the erosion-corrosion resistance of the AC-HVAF coatings in fracturing fluid.%采用喷射冲蚀与电化学测试相结合方法,对AC-HVAF热喷涂非晶金属和金属陶瓷两种涂层在压裂工况下的冲蚀规律进行了研究,评价了腐蚀和冲蚀的交互作用,分析了耐蚀性和硬度在冲蚀时的主导作用,确定了冲蚀机理.结果表明,硬度决定材料的抗冲蚀性能,硬度高的WC涂层表现出更高的抗冲蚀能力.冲蚀过程中,纯机械冲刷引起的失重占主导作用.交互作用中,涂层由腐蚀引起的增量占比例则较高,提高涂层耐蚀性可以减少交互作用失重,进而提高其抗冲蚀性能.AC-HVAF涂层表面则呈现出脆性冲蚀特征,冲蚀时侧重于固体砂粒对表面的碰撞和切削剥蚀作用.涂层孔隙的降低和粘结相结合强度的提高是提高其在压裂液中抗冲蚀性能的关键.
展开▼
