Effect of cooling rate after heat treatment at high temperature in the localized corrosion of UNS S31803 steel
DAVI PEREIRA GARCIA1; Marcelo Camargo Severo de Macedo2; Sergio Souto Maior Tavares3
1 IFES; 2 UFES; 3 UFF
doi:10.20906/CPS/COB-2015-0187
Resumo
Duplex Stainless Steel has both phases, ferrite and austenite, in his microstructure in almost equal proportions, allowing it to have great strength corrosion and mechanical resistance. When exposed to high temperatures they are subject to microstructural changes making his properties to be modified. In this work localized corrosion resistance of the duplex stainless steel UNS S31803 heat treated by high temperature (1300◦C) for 30 minutes followed by different cooling rates is studied. Some samples were solution treated at 1000◦C for 1 hour and fast cooled after the high temperature treatment. A wide range of microstructures, with differents morphologies and phase proportions, were obtained by this way, also this microstructural changes during cooling process have promoted the precipitation of deleterious phases such as nitrides and sigma, making the corrosion strength to be altered.
Palavras-chave: Duplex Stainless Steel UNS S31803; High temperature heat treatment; cooling rates; deleterious phases; DL-EPR; Potentiodynamic Polarization