Hot corrosion behaviour of HVOF-sprayed NiCrBSi coatings on Ni- and Fe-based superalloys in Na2SO4-60% V2O5 environment at 900 °C
Hot corrosion behaviour of HVOF-sprayed NiCrBSi coatings on Ni- and Fe-based superalloys in Na2SO4-60% V2O5 environment at 900 °C
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DOI：
10.1016/j.actamat.2005.10.009
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发表时间：
2006-02-01
期刊：
影响因子：
9.4
通讯作者：
Agrawal, RD
中科院分区：
文献类型：
--
作者：
Sidhu, TS;Prakash, S;Agrawal, RD
为了延长在高温腐蚀环境中使用的部件的使用寿命，需要研究耐高温腐蚀涂层。在900℃的熔融盐（Na2SO4-60% V2O5）循环氧化条件下，研究了高速氧燃料（HVOF）喷涂镍基和铁基高温合金NiCrBSi涂层的性能。采用热重技术建立了腐蚀动力学。采用x射线衍射、扫描电镜/能量色散分析和电子探针微分析技术对涂层和腐蚀产物进行了表征。在给定的环境条件下，裸露的高温合金通常会遭受加速腐蚀，并表现出氧化层的剥落/溅射。镍基高温合金的耐热腐蚀性能优于铁基高温合金。在900℃熔盐环境下，NiCrBSi涂层在降低腐蚀速率方面非常有效。NiCrBSi涂层的耐热腐蚀性能可能归因于硅、铬、镍的氧化物和镍、铬的尖晶石的形成。(c) 2005材料学报Elsevier Ltd.出版。版权所有。
The investigation of high-temperature corrosion-resistant coatings is required so that the service lifetime of components used at higher temperatures in corrosive environments can be prolonged. This study is concerned with the performance evaluation of high-velocity oxyfuel (HVOF)-sprayed NiCrBSi coatings on Ni- and Fe-based superalloys in a molten salt (Na2SO4-60% V2O5) environment at 900 degrees C under cyclic oxidation conditions. The thermogravimetric technique was used to establish the kinetics of corrosion. X-ray diffraction, scanning electron microscopy/energy-dispersive analysis and electron probe microanalysis techniques were used to characterise the as-sprayed coatings and corrosion products. The bare superalloys, in general, suffered accelerated corrosion under the given environmental conditions and showed spalling/sputtering of the oxide scale. The hot corrosion resistance of Ni-based superalloys was found to be better than that of Fe-based superalloys. The NiCrBSi coating was found to be very effective in decreasing the corrosion rate in the given molten salt environment at 900 degrees C. The hot corrosion resistance imparted by NiCrBSi coatings may be attributed to the formation of oxides of silicon, chromium and nickel and spinels of nickel and chromium. (c) 2005 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.