TY - JOUR
T1 - Effect of Co and Fe contents on the microstructure and corrosion behaviour of heat-treated Ni-Fe-Co superalloys in 3.5 wt% NaCl aqueous solution
AU - Bopape, Itshepeng Mogaleadi Christinah
AU - Ogunmuyiwa, Enoch Nifise
AU - Shongwe, Mxolisi Brendon
AU - Mphasha, Nthape Percyval
AU - Ntholeng, Nthabiseng
N1 - Funding Information:
This work is based on the research supported by the National Research Foundation of South Africa for the grant, Unique Grant No. 99348.
Publisher Copyright:
© 2021, The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature.
PY - 2021/10/29
Y1 - 2021/10/29
N2 - The effect of chemical composition on the corrosion behaviour of heat-treated Ni-Fe-Co superalloys has been investigated in aerated 3.5 wt% NaCl aqueous solution. Nickel-base alloys with varying amounts of Fe (5–20 wt%) and Co (30–45 wt%) were fabricated via spark plasma sintering. The alloys were heat-treated at 1000 ∘C in a muffle furnace for 1 hour, and then quenched in distilled water for 5 minutes. Corrosion resistance of the alloys was analysed by measuring potentiodynamic polarization. Corrosion parameters, i.e. Ecorr, icorr, Epass and ipass, were compared for different Co and Fe contents to establish a relationship between the alloy composition and corrosion properties. The results showed that the corrosion resistance of the alloys improved with increasing Co and decreasing Fe content. Accordingly, corrosion rate and corrosion current density (icorr) decreased with increasing Co content and the imposition of heat treatment. Ni-5Fe-45Co (wt%) showed the highest resistance to corrosion with corrosion rates of 0.0145 and 0.00294 mm/year in as-sintered and heat-treated conditions, respectively. Generally, heat treatment improved the grain homogeneity of the microstructures. Characterisation of surface morphologies of as-sintered and heat-treated corroded alloys was conducted using X-ray diffraction (XRD) and scanning electron microscopy (SEM) equipped with energy-dispersive spectroscopy (EDS). [Figure not available: see fulltext.]
AB - The effect of chemical composition on the corrosion behaviour of heat-treated Ni-Fe-Co superalloys has been investigated in aerated 3.5 wt% NaCl aqueous solution. Nickel-base alloys with varying amounts of Fe (5–20 wt%) and Co (30–45 wt%) were fabricated via spark plasma sintering. The alloys were heat-treated at 1000 ∘C in a muffle furnace for 1 hour, and then quenched in distilled water for 5 minutes. Corrosion resistance of the alloys was analysed by measuring potentiodynamic polarization. Corrosion parameters, i.e. Ecorr, icorr, Epass and ipass, were compared for different Co and Fe contents to establish a relationship between the alloy composition and corrosion properties. The results showed that the corrosion resistance of the alloys improved with increasing Co and decreasing Fe content. Accordingly, corrosion rate and corrosion current density (icorr) decreased with increasing Co content and the imposition of heat treatment. Ni-5Fe-45Co (wt%) showed the highest resistance to corrosion with corrosion rates of 0.0145 and 0.00294 mm/year in as-sintered and heat-treated conditions, respectively. Generally, heat treatment improved the grain homogeneity of the microstructures. Characterisation of surface morphologies of as-sintered and heat-treated corroded alloys was conducted using X-ray diffraction (XRD) and scanning electron microscopy (SEM) equipped with energy-dispersive spectroscopy (EDS). [Figure not available: see fulltext.]
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U2 - 10.1007/s00170-021-08111-1
DO - 10.1007/s00170-021-08111-1
M3 - Article
AN - SCOPUS:85118235950
SN - 0268-3768
VL - 119
SP - 287
EP - 301
JO - International Journal of Advanced Manufacturing Technology
JF - International Journal of Advanced Manufacturing Technology
IS - 1-2
ER -