为了解决Cr3C2涂层与304 不锈钢热膨胀系数不匹配的问题，提高304 不锈钢的耐腐蚀性，采用磁控溅射技术在304 不锈钢表面制备了2 种不同结构的Cr3C2/Cr2AlC MAX 复合涂层。 利用SEM、XRD 和EDS 技术表征了涂层的组织结构、相组成，对比分析了不同结构Cr3C2/Cr2AlC MAX 复合涂层与单层Cr2AlC MAX 涂层在熔融多硫化钠中的耐腐蚀性能和腐蚀行为。 结果表明，Cr3C2/Cr2AlC MAX 复合涂层致密均匀，主要由Cr3C2、Cr2AlC MAX相组成。 腐蚀120 h 后，Cr3C2/Cr2AlC MAX 复合双层涂层的腐蚀速率为0.03 mg/(m2∙h)，Cr3C2/Cr2AlC MAX 复合多层涂层的腐蚀速率为0.02 mg/(m2∙h)，比单层Cr2AlC MAX 涂层的腐蚀速率低了2 个数量级。 在多硫化钠中腐蚀后，2 种Cr3C2/Cr2AlC MAX 相复合涂层表面均形成了致密的Cr2S3腐蚀产物层。 经过120 h 腐蚀后，复合双层涂层表面出现裂纹，这是由于热应力集中引起的涂层表面开裂。 但是，复合多层涂层在长时间腐蚀后仍然致密无缺陷，复合多层涂层在多硫化钠腐蚀中表现出优异的耐腐蚀性和稳定性。
崔星铖, 任延杰, 肖彪, 李燕华, 陈荐, 周立波, 邱玮, 黄伟颖, 牛焱
. 不锈钢表面Cr3C2/Cr2AlC MAX相复合涂层在熔融多硫化钠中的高温腐蚀行为[J]. 材料保护, 2025
, 58(6)
: 143
-150
.
DOI: 10.16577/j.issn.1001-1560.2025.0105
In order to address the issue of thermal expansion coefficient mismatch between Cr3C2 coatings and 304 stainless steel, and to enhance the corrosion resistance of 304 stainless steel, two different structural Cr3C2/Cr2AlC MAX composite coatings were prepared on the surface of 304 stainless steel using magnetron sputtering technology.The microstructure and phase composition of the coatings were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) techniques.A comparative analysis was conducted on the corrosion resistance and behavior of Cr3C2/Cr2AlC MAX composite coatings with different structures in molten sodium polysulfide, as well as a single-layer Cr2AlC MAX coating.Results showed that the Cr3C2/Cr2AlC MAX composite coatings were dense and uniform, and were primarily composed of Cr3C2 and Cr2AlC MAX phases.After 120 h of corrosion, the corrosion rate of the Cr3C2/Cr2AlC MAX composite double-layer coating was measured at 0.03 mg/(m2∙h), while the corrosion rate of the Cr3C2/Cr2AlC MAX composite multilayer coating was recorded at 0.02 mg/(m2∙h),which was two orders of magnitude lower than that of the single-layer Cr2AlC MAX coating.Following corrosion in sodium polysulfide,a dense layer of Cr2S3 corrosion products was formed on the surfaces of both types of Cr3C2/Cr2AlC MAX composite coatings.After 120 h of corrosion,cracks were observed on the surface of the composite double-layer coating,which were attributed to thermal stress concentration leading to surface cracking.In contrast, the composite multilayer coating remained dense and defect-free even after prolonged exposure to corrosion, and was shown to demonstrate excellent corrosion resistance and stability in sodium polysulfide environments.
