CO2气氛和喷涂距离对电弧喷涂铁基非晶涂层组织及耐蚀性能的影响

为提高电弧喷涂铁基非晶涂层的非晶含量及耐蚀性,以CO₂为载流气体代替空气进行电弧喷涂试验,并研究喷涂距离对涂层组织与耐蚀性的影响。结果表明,喷涂层的厚度约为200 μm,涂层均主要由结晶相与非晶相构成。相比于空气介质,CO₂抑制了晶化,从而提高了涂层中的非晶含量。同时,喷涂距离对涂层的组织及耐蚀性能有较大影响。随着喷涂距离的增加,涂层中的非晶含量减少。当喷涂距离为100 mm时,涂层具有最高的开路电位-0.498 V(vs SCE)及最小的自腐蚀电流密度4.281 μA/cm²,耐蚀性能最好;当喷涂距离为150 mm时,涂层的耐蚀性最差。提高非晶含量和组织的均匀性可增强该涂层的耐蚀性能。

Effect of CO2 atmosphere and spraying distance on microstructure and corrosion resistance of arc sprayed Fe-based amorphous coating

To increase the amorphous content and corrosion resistance of arc sprayed Fe-based amorphous coating, CO₂ atmosphere was used instead of air for arc spraying and the effect of spraying distance on microstructure and corrosion resistance of the coatings was studied. The results show that the thickness of the coating is about 200 μm and the coating consists of crystalline phase and amorphous phase. Compared with air, the CO₂ inhibits the crystallization, which leads to the amorphous content increase in the coating. Meanwhile, the spraying distance has a great influence on microstructure and corrosion resistance of the coating. With the increase of spraying distance, the amorphous content decreases. When the spraying distance is 100 mm, the coating has the highest open circuit potential of -0.498 V(vs SCE) and the smallest self-corrosion current density of 4.281 μA/cm², the best corrosion resistance can be obtained. The corrosion resistance of the coating is the worst when the spraying distance is 150 mm. The increase of amorphous content and the uniformity of the microstructure can enhance the corrosion resistance of the coating.