FeCrBSiC电弧喷涂层磨损及热腐蚀性能研究

Wear and Hot Corrosion Resistance of FeCrBSiC Coating Prepared by Wire-arc Spraying

设计开发了一种FeCrBSiC粉芯丝材,采用电弧喷涂技术在Q235钢基体上制备相应涂层,通过XRD、SEM、磨粒磨损试验机及高温箱式电阻炉等对其微观组织结构、磨粒磨损及热腐蚀行为进行表征,同时与工程中广泛应用的NiCrTi涂层进行了对比研究。结果表明,涂层均具有热喷涂典型的层状结构,且较为致密,孔隙率低于3%;Fe基涂层组织更为均匀,其氧化物含量显著低于Ni基涂层。所设计Fe基涂层平均显微硬度约为1107.3HV0.1,其耐磨性也更为优异,达到Ni基涂层4倍以上。两种涂层在650℃时的热腐蚀动力学曲线均呈抛物线形式,表面生成连续致密的氧化膜阻止了腐蚀介质向涂层内部的渗透,能够对基体起到有效的防护作用。

A new FeCrBSiC cored wire was designed to prepare coatings by wire-arc spraying on Q235 substrate. The microstructure, wear and hot corrosion behavior of the Fe-based coating were investigated in the meaning of X-ray diffractometry （XRD）, scanning electron microscopy （SEM）, abrasive wear test machine and high- temperature muffle furnace, in comparison with that of the traditional NiCrTi coating. The results show that both of the coatings exhibit dense layered structure with the porosity below 3%, and the Fe-based coating expresses more homogeneous structure with lower oxides content than Ni-based coating. The average microhardness of Fe- based coating can be achieved approximately 1107.3 HV01, thus leading to their superior wear resistance than Ni-based coating. Thermo-gravimetric curves of the two coatings follow the parabolic law, which implies their effective ability to protect substrates withstanding hot corrosion, due to the formation of successive and compact surface oxide scale which prevents the diffusing or penetrating of the corrosive species.