engleski

Influence of thermal oxides on pitting corrosion of austenitic and duplex steels

The influence of thermal oxides on the pitting corrosion of austenitic and duplex (austenitic-ferrite) steels has been studied. Austenitic steel specimens AISI 316L were subjected to heating isothermally (200 to 1000 oC) in order to simulate conditions of the application in production. Duplex steel specimens AISI S31803 were heated isothermally at (1100 to 1300 oC) in order to simulate welding parameters. The characterization of thermal oxides formed by heating isothermally on austenitic steel was performed by AES, and XPS analyses. The microstructures and thickness of thermal oxides on austenitic specimens and microstructures on duplex specimens was determined. Pitting susceptibility of such specimens was tested by exposure to FeCl3 solution at 22 ± ; ; 2 oC during 72 h (ASTM G 48-99a). Pitting criteria show that oxides developed at 600 oC cause the highest susceptibility to pitting corrosion for austenitic steel and 1300 oC for duplex steel.

thermal oxides; austenitic; duplex; pitting

nije evidentirano