Faculty Publications

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Author: search.filters.author.Arya, S.B.Subject: search.filters.subject.Corrosion behaviour

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    Plasma nitriding of AISI 2205 steel: Effects of surface mechanical attrition treatment and chemical etching
    (Maney Publishing michael.wagreich@univie.ac.at, 2016) Gatey, A.M.; Hosmani, S.S.; Arya, S.B.; Figueroa, C.A.; Singh, R.P.
    In the present study, surface mechanical attrition treatment (SMAT) and plasma nitriding were conducted on AISI 2205 steel. SMAT was effective in enhancing the surface hardness of the steel by about 80%. The influence of SMAT on the corrosion behaviour of the steel was studied in a 3.5 wt-% NaCl solution. Due to the stable and thicker passive layer, improved corrosion resistance was observed for the SMATed steel. However, nitrogen diffusion during plasma nitriding was impeded by the improved passivation, especially for the lower duration (30 min) of chemical etching/cleaning (i.e. sputter cleaning in hydrogen plasma) of the specimen's surface. Furthermore, high chemical etching duration (120 min) resulted in improved surface hardness and nitriding kinetics. © 2016 Institute of Materials, Minerals and Mining.
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    Hot corrosion behavior of Al2O3 + Sm2SrAl2O7 composite thermal barrier coatings
    (John Wiley and Sons Inc, 2022) Joseph, F.J.; Arya, S.B.; Tailor, S.
    Rare earth-based samarium strontium aluminate (Sm2SrAl2O7) powder has been synthesized in the laboratory through molten salt synthesis and Al2O3 + Sm2SrAl2O7 (SSA) thermal barrier coatings have been developed on an Inconel 718 superalloy substrate by atmospheric plasma spraying technique. The microstructures and surface morphologies of the samples before and after the hot corrosion tests in 50 wt% Na2SO4 + 50 wt% V2O5 (aviation atmosphere) and 90 wt% Na2SO4 + 5 wt% V2O5 + 5 wt% NaCl (marine atmosphere) at 700°C and 900°C were examined. It is observed that samples exposed to marine conditions exhibited 14.5% and 11.6% lower lifetime than the samples exposed to aviation conditions at 700°C and 900°C, respectively, due to significant chlorides attack. © 2022 Wiley-VCH GmbH.
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    Hot corrosion behaviour of mullite thermal barrier coatings for marine diesel engines
    (Elsevier Ltd, 2024) K, S.; Babu, N.; Cadambi, S.; Arya, S.B.
    Mullite's inherent qualities have made it a potential material for the application of thermal barrier coatings (TBCs) for diesel engine components. Hot corrosion at 600–800 °C can cause TBC degradation, thus significantly affecting the performance of engine components and reducing their service life. This work examines the hot corrosion behaviour of atmospheric plasma-sprayed (APS) mullite coating over NiCrAlY bond coat on mild steel substrates. The coated specimen surface was covered with a mixture of Na2SO4 (sodium sulphate) and V2O5 (vanadium pentoxide) in the form of paste and heated in a muffle furnace at 700 °C for up to 300 h. SEM, EDS, and XRD characterisations were used to investigate the mechanism of hot corrosion. Coatings remained intact after corrosion tests; however, it had reacted with corrosive salts, particularly sodium sulphate. This was evidenced by the removal of amorphous silica, followed by the formation of nosean as a major phase. During the reaction between sodium sulphate and mullite coating, vanadium pentoxide was found to be acting as a flux and mineraliser. © 2023 Elsevier Ltd and Techna Group S.r.l.
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    Enhancing X70 steel durability: Tribo-corrosion resistance through protective laser cladding
    (Elsevier Ltd, 2025) Singh, R.K.; Bhole, K.B.; Arya, S.B.; Nayak, J.
    This study investigates the effects of laser surface cladding (L-DED technique) on the tribo-corrosion behavior of API X70 steel in the simulated Indian oilfield water. Using optimized parameters, 500 W laser power, 720 mm/min scan speed, and 4.2 g/min powder feed rate, 316 L SS was successfully clad onto X70 steel without any significant defects. The results showed a significant improvement in corrosion resistance, with the SS clad exhibiting a corrosion rate of 131.3 ?m/year at 20 N, compared to 287.9 ?m/year for the X70 substrate. SEM and 3D profilometer analyses revealed a more stable tribo-layer on the SS clad, with less damage and debris accumulation. These findings highlight the potential of laser cladding to enhance the durability and lifespan of steel components. © 2025 Elsevier Ltd