Characterization of a Cast Duplex Stainless Steel with 3.0%Cu and Modeling of Precipitation Hardening
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Duplex stainless steels (DSSs) are corrosion-resistant alloys extensively used in aggressive environments. Cast DSSs may be selected for pipes, valves and pumps in chemical, petrochemical and nuclear industries. The grade steel ASTM A890 1B is an example of cast DSS with 2.7-3.3%Cu addition. Copper increases the resistance to many types of corrosion, especially in non-oxidizing environments. When the copper content is higher than 2%, the steel can be precipitation-hardened. In this work, the precipitation hardening of a DSS ASTM A890 1B steel with 3.0%Cu was studied and modeled for aging temperatures in the 450-600 °C range. Copper precipitates in the ferrite phase, but remains in solid solution in the austenite. The age hardening curves were modeled by ΔH = K(t)n model, where ΔH is the increase in hardness, t is the aging time, and K and n are constants to be determined. The microstructure and substructure were investigated by scanning electron and transmission electron microscopes.
Keywordsaging precipitation hardening stainless steel
Authors are grateful to Brazilian Research Agencies CAPES, CNPq and FAPERJ for financial support.
- 1.ASM Speciality Handbook: Stainless Steels. ASM International.Google Scholar
- 2.R.N. Gunn, Duplex Stainless Steels: Microstructure, Properties and Applications, Abington Publishing, Cambridge, 2003Google Scholar
- 3.A. Loureiro, V.C. da Costa, J.M. Pardal, T.R. Montenegro, and S.S.M. Tavares, Influence of Heat Treatments at 475 °C and 400 °C on the Pitting Corrosion Resistance and Sensitization of UNS S32750 and UNS S32760 Superduplex Stainless Steels, Mater. Corros., 2012, 63, p 522Google Scholar
- 10.ASTM A890—standard specification for castings, iron–chromium–nickel–molybdenum corrosion-resistant, duplex (austenitic/ferritic) for general application. ASTM, West Conshohocken; 2000.Google Scholar
- 11.I.A. Armas and S. Degallaix-Moreuil, Duplex Stainless Steels, Wiley, New York, 2009Google Scholar
- 14.P. Li, Y. Zhao, Y. Liu, Y. Zhao, D. Xu, C. Yang, T. Zhang, T. Gu, and K. Yang, Effect of Cu Addition to 2205 Duplex Stainless Steel on the Resistance Against Pitting Corrosion by the Pseudomonas aeruginosa Biofilm, J. Mater. Sci. Technol., 2017, 33, p 23Google Scholar
- 20.I. Le May and L.M. Schetky, Copper in Iron and Steel, Wiley, New York, 1982Google Scholar