SciELO - Scientific Electronic Library Online

 
vol.66 issue4Analysis of pig iron desulfurization with mixtures from the CaO-Fluorspar and CaO-Sodalite system with the use of computational thermodynamicsSimulation of a ball mill operating with a low ball charge level and a balanced ball size distribution author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand

Journal

Article

Indicators

Related links

Share


Rem: Revista Escola de Minas

Print version ISSN 0370-4467

Abstract

ITMAN FILHO, André et al. Austenitic-ferritic stainless steel containing niobium. Rem: Rev. Esc. Minas [online]. 2013, vol.66, n.4, pp.467-471. ISSN 0370-4467.  http://dx.doi.org/10.1590/S0370-44672013000400010.

The austenitic-ferritic stainless steels present a better combination of mechanical properties and stress corrosion resistance than the ferritic or austenitic ones. The microstructures of these steels depend on the chemical compositions and heat treatments. In these steels, solidification starts at about 1450ºC with the formation of ferrite, austenite at about 1300ºC and sigma phase in the range of 600 to 950ºC.The latter undertakes the corrosion resistance and the toughness of these steels. According to literature, niobium has a great influence in the transformation phase of austenitic-ferritic stainless steels. This study evaluated the effect of niobium in the microstructure, microhardness and charge transfer resistance of one austenitic-ferritic stainless steel. The samples were annealed at 1050ºC and aged at 850ºC to promote formation of the sigma phase. The corrosion testes were carried out in artificial saliva solution. The addition of 0.5% Nb in the steel led to the formation of the Laves phase.This phase, associated with the sigma phase, increases the hardness of the steel, although with a reduction in the values of the charge transfer resistance.

Keywords : Austenitic-ferritic stainless steels; sigma phase; Laves phase; charge transfer resistance.

        · abstract in Portuguese     · text in English     · English ( pdf )

 

Creative Commons License All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License