The effect of surface treatment on the susceptibility to metal dusting of 304L stainless steel (SS) exposed in a mixed gas of CO/CO2 = 100/1 in the temperature ranging from 500-700° C was investigated. Thermogravimetric analyses (TGA) and long-term exposure tests in the above environments, followed by surface-morphological examination and cross-section chemical composition and microstructure analyses were conducted. The results showed that the decomposition of CO gas to form graphite and nano-sized carbon filaments was affected by the surface pre-treatment applied on the 304L SS. Enhanced carbon deposition but with a significant resistance to metal dusting was found on the sand-blasted 304L SS. The existence of an initial non-protective oxide on the pre-oxidized 304L SS surface, however, gave rise to the highest susceptibility to metal-dusting-associated-localized attack. The roles of different surface treatments on the reactions between 304L SS and the exposing gas environment are discussed.
All Science Journal Classification (ASJC) codes
- Inorganic Chemistry
- Metals and Alloys
- Materials Chemistry