Corrosion resistance of cu-alloyed precipitation hardenable duplex stainless steel ASTM A890 Grade 1B

Duplex stainless steels (DSS) are corrosion resistant alloys largely used in chemical and petrochemical industries. Some commercial DSS contain 0.5-1.0% copper addition to improve the corrosion resistance by reducing the corrosion rate in non-oxidizing environments. Higher copper addition (≥ 2%) can...

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Detalles Bibliográficos
Autores: Lima, Hillane Mirelle Lopes Ferreira de, Tavares, Sérgio Souto Maior, Bastos, Ivan Napoleão, Rodrigues, Matheus Souza, Martins, Marcelo, Araújo, Walney Silva
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2019
País:Brasil
Institución:Universidade Federal do Ceará (UFC)
Repositorio:Repositório Institucional da Universidade Federal do Ceará (UFC)
Idioma:inglés
OAI Identifier:oai:repositorio.ufc.br:riufc/59297
Acceso en línea:http://www.repositorio.ufc.br/handle/riufc/59297
Access Level:acceso abierto
Palabra clave:Cast duplex stainless steel
Copper
Passive film
Descripción
Sumario:Duplex stainless steels (DSS) are corrosion resistant alloys largely used in chemical and petrochemical industries. Some commercial DSS contain 0.5-1.0% copper addition to improve the corrosion resistance by reducing the corrosion rate in non-oxidizing environments. Higher copper addition (≥ 2%) can also hard by precipitation, especially when fine copper precipitates (ε phase) are produced. In this work, a cast copper alloyed DSS type ASTM A890 grade 1B with 3.01%Cu was investigated. Different levels of hardness were produced by solution treatment and aging at 450, 500, 550 and 600 oC for periods of time up to 1 hour. The corrosion resistance of aged DSS was evaluated by electrochemical tests in three media: 0.6 mol/L NaCl, 0.3 mol/L H2SO4 and 0.6 mol/L NaCl + 0.3 mol/L H2SO4 solutions. The results indicate that the effect of Cu addition depends on the media studied. Polarization studies in 0.6 mol/L NaCl showed a small anodic current peak occurred at around 400 mV vs. Ag/AgCl, with a strong influence on the passive film stability. Additionally, chronoamperometric measurements at 400 mV vs. Ag/AgCl showed a high electrochemical activity for the samples in 0.6 mol/L NaCl.