Technical Note: Hot Corrosion Resistance of Nano-Structured Sol-Gel Alumina-Coated 9Cr-1Mo Ferritic Steel in Air/Salt Environments

被引：3

作者：

Ruhi, G. ^{[1
]}

Modi, O. P. ^{[1
]}

Singh, M. ^{[1
]}

Khare, A. K. ^{[1
]}

Singh, I. B. ^{[1
]}

机构：

[1] CSIR Adv Mat & Proc Res Inst, Bhopal 462064, MP, India

来源：

CORROSION | 2014年 / 70卷 / 02期

关键词：

9Cr-1Mo ferritic steel; oxidation kinetics; salt systems; sol-gel coatings; ZIRCONIA COATINGS; MILD-STEEL; OXIDATION; PROTECTION;

D O I：

10.5006/0978

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Synthesized boehmite (AlO[OH]) sol was deposited on 9Cr-1Mo ferritic steel substrates using a dip coating technique. The coated substrates were heat-treated at 300 degrees C to obtain a precursor-free alumina coating. Atomic force microscopy (AFM) analysis of the coated surfaces confirmed the presence of nano-sized alumina particles (8 nm to 12 nm) in the coating. The alumina-coated and uncoated samples were subjected to a hot corrosion test in lithium chloride-sodium chloride (LiCl-NaCl) and sodium sulfate-potassium sulfate (Na2SO4-K2SO4) salt mixtures separately at 650 degrees C and 850 degrees C, respectively. Oxidation kinetics study has indicated a significant improvement in the hot corrosion resistances of the coated substrates. Microstructural examinations of the oxidized substrates have revealed the presence of comparatively compact and less porous oxide scale at the coated specimens, whereas relatively very thick scale filled with cracks and voids were noticed on the uncoated oxidized specimens.

引用

页码：130 / 136

页数：7