Hot-corrosion of AISI 1020 steel in a molten NaCl/Na2SO4 eutectic at 700°C

High-Temperature Corrosion Behavior of Selected HVOF-Sprayed Super-Alloy Based Coatings in Aggressive Environment at 800 °C

“…The durability and reliability of power generation equipment are important parameters affecting the stability of the energy market. In the case of components of combustion plants, such as boiler firewalls, heat exchangers, or pressure vessels of coal-fired power plants, the service life is often limited by the corrosion attack of an aggressive environment, where hot corrosion is especially a major issue determining the service life of said components [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ]. Hot corrosion has been identified as a serious problem for many high-temperature aggressive environment applications, such as boilers [ 1 , 2 , 4 , 5 , 6 , 7 , 8 , 11 , 12 , 14 ], internal combustion engines, gas turbines [ 15 , 16 ], fluidized bed combustion boilers [ 17 ], industrial waste incinerators [ 18 , 19 ], etc.…”

“…A chemical reaction then takes place, which initially attacks the protective oxide film and continuously reduces the chromium (Cr) content of the substrate materials. As a result of the reduction in chromium content, oxidation of the substrate increases rapidly and porous deposits are formed [ 5 , 7 , 8 ]. The reaction producing metal chlorides or sulphides near the oxide/metal consumes metallic elements, especially chromium.…”

“…If alloy contains aluminum, alumina (Al 2 O 3 ) is also found in the oxide layer [ 8 ]. Solid salt deposits are deposited on the oxide scale and when the temperature rises above the melting point of the salt deposits, the salt mixture becomes liquid or partially liquid [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ]. This is when the temperature threshold at hot corrosion type I begins to occur.…”

“…This is when the temperature threshold at hot corrosion type I begins to occur. The actual melting temperature depends on the salt mixture composition, but the melting temperature of the salt mixture is usually below melting temperature of its component due to eutectic character of the mixture [ 4 , 5 , 6 , 7 , 8 , 9 ].…”

“…Other material elements such as nickel or titanium are also subject to these reactions [ 1 , 2 , 3 , 4 , 5 , 7 , 8 ].…”