High-temperature oxidation of FeCrAl alloy with alumina–silica–ceria coatings deposited by sol–gel method

Abstract

One-layer protective coatings made up of SiO 2 -Al 2 O 3 or SiO 2 -Al 2 O 3 -CeO 2 oxides were synthesized on a FeCrAl alloy substrate by the sol-gel method from sols containing tetraethyl orthosilicate, aluminum tri-secbutoxide and cerium(III) 2,4-pentanedionate as the precursors. Coating solutions with the Si:Al:Ce molar ratio of 3:1:0, 3:1:0.1; 3:1:0.01, and 3:1:0.001 were used. The composition and morphology of the obtained gels were examined by TG/DSC, XRD, and SEM techniques. It was found that a small addition of cerium affected the morphology of the forming coatings and improved the FeCrAl alloy resistance to high-temperature oxidation (in air at T = 900°C for t = 100 h). The oxidation of all the investigated samples conformed to the parabolic rate. The protection effectiveness of the one-layer coatings after 100 h of high-temperature oxidation was as high as 70 %.

Titanium Influence on the Microstructure of FeCrAl Alloys Used for 4R Generation Nuclear Power Plants

“…The development of lead alloy coolant technologies will allow successful application with maximized efficiency and enhanced safety.The LBE-cooled nuclear energy systems, however, have been exposed to several issues * email: radu.stefanoiu@upb.ro; Phone: 0744606588 arising from the limitation of the system life due to the relatively low corrosion resistance of structural materials in LBE environments. The corrosion behaviours on several types of austenitic and ferritic/martensitic (FM) steels have been extensively studied to investigate the corrosion performance of structural materials and to improve the materials life performance worldwide [1][2][3][4][5][6][7][8][9].…”

“…Titanium reacts with oxygen at temperatures of 600-800 °C according to the reaction: (1) Titanium has high affinity for oxygen, which means that it takes part in the deoxidation processes of the molten metal. The affinity of titanium for oxygen can be evaluated using the equilibrium constant (K Ti = [Ti][O] 2 ), considering that the total amount formed varies with the temperature according to: (2) Since the K TI value is 6.638x10 -8 at 1600 0 C, it follows that the deoxidation power of titanium is greater comparatively with silicon and aluminium. Titanium is also used as a deoxidizer and as an alloying element in ferrous alloys like FeCrAl.…”