Hot Corrosion Behavior of Arc-Sprayed NiCrB and NiCrTi Coatings with Different Oxide Contents

Coatings

Zheng Zhou¹  Xu Wang¹  Wei Shao¹  Dingyong He¹  Xingye Guo¹  Guohong Wang¹ 

[1] Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, China;

关键词: arc spraying;    hot corrosion;    microstructure;    NiCrB and NiCrTi coatings;    oxide content;   

DOI  :  10.3390/coatings12040497

来源: DOAJ

【 摘 要 】

In this study, newly developed NiCrB and conventional NiCrTi coatings were produced by arc spraying using compressed air and nitrogen as atomization gases. In this way, four coatings with different oxide contents were produced. The coatings were investigated in terms of their phase compositions, oxygen contents, and microstructures. The results showed that the oxygen contents in coatings were pronouncedly reduced by nitrogen-atomized compared to air-atomized. The oxygen contents in the nitrogen-atomized coatings were about one-fourth of those in the corresponding air-atomized coatings, respectively. No significant oxide phases were observed in the XRD patterns of the nitrogen-atomized coatings. Moreover, the corrosion behavior of the coatings was studied using a hot corrosion test in molten Na₂SO₄-10 wt.% NaCl salt at T = 800 °C. All coatings were significantly corroded under this test condition. However, NiCrB coatings exhibited higher corrosion resistance than NiCrTi coatings. The NiCrB and NiCrTi coatings prepared by nitrogen atomization corroded more severely in the initial stage than the corresponding coatings prepared by air atomization. The NiCrB coating with air-atomized showed the best corrosion resistance due to the low chromium content and the addition of boron.

【 授权许可】

Unknown