热喷涂FeCrAl/Al复合涂层抗高温硫化的研究

为了提高材料的抗热腐蚀性能,采用电弧喷涂方法在钢铁基体表面施加FeCrAl/Al复合涂层,通过沉积Na2SO4的900℃热腐蚀试验以及二硫化碳生产装置中的现场挂片试验,研究了FeCrAl/Al复合涂层的高温硫化表现。实验结果表明:FeCrAl/Al复合涂层提高了钢铁材料的抗高温硫化腐蚀能力,在高温硫化初期,外表面的Al涂层首先发生氧化,形成连续的Al2O3层,显著地减缓了硫原子向复合涂层内部的扩散速度。随着复合涂层中Cr、Al等有效抗硫化合金元素的相互扩散,形成FeCr金属间化合物层,进一步阻碍硫原子扩散,对钢铁基体材料提供有效的高温硫化防护作用。

Thermal Sprayed FeCrAl/Al Composite Coatings Used for High-Temperature Sulphide Corrosion Protection

In order to improve the material’s ability to against sulphur attack under high temperature,arc-sprayed FeCrAl/Al composite coatings on steel materials were studied in this work.The results of the laboratory experiments and the test under the Charcoal-Sulphur operating condition revealed that the arc sprayed composite coatings of FeCrAl/Al could well protect the steel substrate from high-temperature sulphide corrosion.In the early test,the surface Al coating was priority oxidized and formed into a continuous alumina layer which effectively slowed down the diffusion of sulphur into the steel substrate.After then,the diffusion of the elements including Cr and Al in the composite coatings resulted in the formation of an intermetallic compound which provided a further sulphide corrosion protection.