摘要
采用亚音速火焰喷涂方法在P91钢上制备了NiCr/Cr3C2涂层,研究了样品在600,650和700℃的80%Na2SO4+10%K2SO4+10%KCl(质量分数,后同)混合熔融盐中的热腐蚀行为,利用XRD和SEM分析了表面成分和结构。结果表明:喷涂NiCr/Cr3C2涂层样品在热腐蚀过程中,腐蚀产物从样品表面剥落而在动力学上表现为失重,在700℃样品失重加速。经热腐蚀后,涂层表面的腐蚀产物主要由Ni3S2和Cr2O3组成。由于基体/涂层结合处生成硫化物,造成基体/涂层的弱结合,导致涂层脱落。
NiCr/Cr3C2 coating was prepared on P91 steel by subsonic flame spraying process. The hot corrosion tests of the coated samples were conducted in 80%Na2SO4＋10%K2SO4＋10%KC1 molten salts at 600,650 and 700℃, respectively. The surface morphology and microstructures of corroded samples were examined by XRD and SEM. It is shown that the the corrosion products spall from sample surface on a large scale, which lead to mass loss during the tests. Especially, mass loss is accelerated when the samples are tested at 700℃. After oxidation the corroded products on the samples surface are mainly composed of Ni3O2 and Cr20a. Sulfides layer is observed at the interface of substrate/ coating, which resultes in weak bonding interface and lead to corrosion products spalled from smaple surface during hot corrosion.
出处
《表面技术》
CAS
CSCD
北大核心
2011年第5期25-28,共4页
Surface Technology
