摘要
在Cr25Ni20Si2合金上制备了施加Ni中间层的复合搪瓷涂层,研究了Cr25Ni20Si2合金、搪瓷涂层及含镍中间层的复合搪瓷涂层在800℃熔融盐(75%Na2SO4+25%NaCl)下的腐蚀行为和腐蚀机理。试验表明合金在孕育期结束后发生灾难性腐蚀,腐蚀机理主要遵从硫化-碱融模式;未镀镍搪瓷涂层主要以直接脱落丧失保护能力,复合搪瓷涂层则以物理减薄方式缓慢失效。搪瓷涂层使合金的抗热腐蚀能力提高了30%,复合搪瓷涂层可使合金抗热腐蚀能力提高100%以上。这种复合搪瓷涂层是有效的抗热腐蚀涂层。
The enamel with Ni interlayer coating on Cr25Ni20Si2 alloy was prepared. The hot corrosion behavior and mechanism of Cr25Ni20Si2 alloy and enamel coating on Cr25Ni20Si2 alloy with or without Ni interlayer were investigated in molten salt （75 % Na2 SO2 ＋ 25 % NaCl）at 800℃. The experimental results indicate that the alloy is subject to serious corrosion after the end of incubation period, the hot corrosion mechanism conform to sulfuration-alkalescent melt manner. As the nickel-free enamel fall off directly from the substrate, the enamel coatings loses the ability of protection mostly. The composite enamel coatings become invalid slowly in a manner of physical reducing of the enamel thickness. The hot corrosion resistance can be improved 30% with the enamel coating without Ni interlayer, while the hot corrosion resistance can be improved 100% above with the composite enamel coating, compared with Cr25Ni20Si2 alloy. The composite enamel coating is a efficient protective coating for hot corrosion.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2009年第1期174-177,187,共5页
Transactions of Materials and Heat Treatment
基金
华中科技大学材料成形与模具技术重点实验室开放基金
华中科技大学研究基金资助
