Yang Jun, Sun Yijiao, Su Minwen, Yin Xueming, Li Hongxiang, Zhang Jishan
National Engineering Laboratory for Exploration and Development of Low-Permeability Oil & Gas Fields, Xi'an 710018, China.
Changqing Downhole Technology Company, Chuanqing Drilling Engineering Co., Ltd., Xi'an 710018, China.
Materials (Basel). 2023 Jul 22;16(14):5170. doi: 10.3390/ma16145170.
To suppress the corrosion and erosion wear of dissolvable magnesium alloy ball seats in wellbores, Fe-based amorphous coatings were deposited on dissolvable Mg-RE alloy substrates, and their microstructure, corrosion behavior, and erosion wear behavior were studied. The thickness of Fe-based amorphous coatings on dissolvable Mg-RE alloy substrates can reach 1000 μm without any cracks, and their porosity and amorphous contents are 0.79% and 86.8%, respectively. Although chloride ions will damage the compactness and protective efficacy of passive films, Fe-based amorphous coatings still maintain low corrosion current density (3.31 μA/cm) and high pitting potential (1 V) in 20 wt% KCl solution. Due to their higher hardness, the erosion wear resistance of Fe-based amorphous coatings is about 4.16 times higher than that of dissolvable Mg-RE alloy substrates when the impact angle is 30°. Moreover, the erosion rates of Fe-based amorphous coatings exhibit a nonlinear relationship with the impact angle, and the erosion rate reaches the highest value when the impact angle is 60°. The erosion wear mechanisms of Fe-based AMCs vary with the impact angles, including cutting, delamination, splat fracture, and deformation wear. This work can provide effective guidance for the corrosion and wear protection of plugging tools made from dissolvable magnesium alloy.
为抑制井筒中可溶解镁合金球座的腐蚀和冲蚀磨损，在可溶解Mg-RE合金基体上沉积了铁基非晶涂层，并研究了其微观结构、腐蚀行为和冲蚀磨损行为。可溶解Mg-RE合金基体上铁基非晶涂层的厚度可达1000μm且无任何裂纹，其孔隙率和非晶含量分别为0.79%和86.8%。尽管氯离子会破坏钝化膜的致密性和保护效果，但铁基非晶涂层在20 wt% KCl溶液中仍保持较低的腐蚀电流密度（3.31 μA/cm）和较高的点蚀电位（1 V）。由于其硬度较高，当冲击角为30°时，铁基非晶涂层的抗冲蚀磨损性能比可溶解Mg-RE合金基体高约4.16倍。此外，铁基非晶涂层的冲蚀速率与冲击角呈非线性关系，当冲击角为60°时冲蚀速率达到最高值。铁基非晶涂层的冲蚀磨损机制随冲击角而变化，包括切削、分层、飞溅断裂和变形磨损。这项工作可为可溶解镁合金制成的封堵工具的腐蚀和磨损防护提供有效指导。
