CHEM02200704003 Nilamadhab Pandhy - Homi Bhabha National ...

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Chapter 5 correlation between surface analytical studies and corrosion resistance of 304L SS in 1 M nitric acid is well observed. With increase in nitrogen ion dose, decrease in passivation current density, corrosion current density and marginal increase transpassive potential revealing improvement in corrosion resistance was observed. Similarly, in both SIMS and XPS analysis increase in nitrogen intensity revealing enrichment of nitrogen as well as formation of chromium nitride was observed. Thus, the beneficial role of nitrogen from corrosion results with surface analysis using SIMS and XPS can be well correlated. 5.2. 9 Surface morphology study after potentiodynamic polarization Surface morphology analysis of the unimplanted and nitrogen ion implanted samples with dose of 1×10 16 and 2.5×10 17 N + /cm 2 after potentiodynamic polarization experiment investigated using AFM are as shown in Fig. 5.9a-c [21]. Distinctive surface morphologies were observed depending on the dose of nitrogen implantation, as clear from the topographic images indicating effect of nitrogen in slowing down the surface dissolution process leading to improvement in corrosion resistance. The unimplnated samples showed grain boundary dissolution in nitric acid medium with visibility of well demarked grain boundaries (Fig. 5.9a). The large damage, and highly corrugated surface morphology is due to intergranular corrosion of austenitic stainless steel occurring in nitric acid medium [20,21]. The extent of grain boundary dissolution lessened at a dose of 1×10 16 N + /cm 2 (Fig. 5.9b) as less clear grain boundaries were visible. At highest dose of implantation of 2.5×10 17 N + /cm 2 the grain boundary dissolution disappeared and at some places selective attack was observed (Fig. 5.10c). The selective attack is attributed to the presence of surface inhomogenities on the surface. The root mean square roughness (R q ) calculated for the aforementioned polarized test samples in 1 M nitric acid are, 238 nm for unimplanted, 110 nm for dose of 1×10 16 N + /cm 2 and 46 nm for
Chapter 5 dose of 2.5×10 17 N + /cm 2 , respectively. The decrease in root mean square roughness with increase in nitrogen ion implantation dose after polarization is attributed to lesser surface dissolution [21]. (a) (b) (c) Fig.5.9: AFM surface morphology after potentiodynamic polarization study, Unimplanted (b) 1×10 16 and (c) 2.5×10 17 N + /cm 2 [21] Surface morphology investigation by Picard et al [143] on corroded samples of low energy nitrogen implanted austenitic stainless steel has revealed alternate black, and white regions in acidic media due to topographic contrasts, and preferential etching in the twinning directions. However, in the present study such topographical demarcations were not observed, and only grain
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2.3 Effect of alloying elements on
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6.2.3.2 Open circuit potential vs.
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eprocessing can be recovered, and c
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The ex-situ study of passive film w
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Fig.3.10: Schematic of electrical e
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Fig.6.11: Polarization study of unc
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AISI: American Institute of Steel I
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Chapter 1 C H A P T E R 1 Spent Nuc
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Chapter 1 1.3 Challenges in spent n
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Chapter 1 corrosion resistance. The
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Chapter 1 choice of zirconium is du
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C H A P T E R2
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Chapter 2 temperature, (c) higher i
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Chapter 2 Chromium in excess of 12
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Chapter 2 2. 3 Effect of alloying e
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Chapter 2 The twins are identified
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Chapter 2 and at temperature around
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Chapter 2 of adsorption of oxygen o
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Chapter 2 transpassive dissolution
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Chapter 2 healing chromium oxide fi
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Chapter 2 their segregation to the
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Chapter 2 is intimately related to
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Chapter 2 in nature because the dis
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C H A P T E R3
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Chapter 3 3.1.1.2 Specimen preparat
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Chapter 3 ionized. However, differe
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Chapter 3 various industrial applic
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Chapter 3 In the present investigat
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Chapter 3 3.1.3.2 Atomic force micr
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Chapter 3 present on the surface fo
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Chapter 3 necessary condition is th
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Chapter 3 Y m is the sputter yield.
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Chapter 3 Fig. 3.7: Schematic of X-
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Chapter 3 rate of 10Å/min using 5
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Chapter 3 different doses of nitrog
Page 80 and 81: Chapter 3 The modulus of electroche
Page 82 and 83: Chapter 3 equivalent circuit as sho
Page 84 and 85: Chapter 3 reference electrode with
Page 86 and 87: Chapter 3 for understanding the pas
Page 88 and 89: C H A P T E R4
Page 90 and 91: Chapter 4 encountered by all materi
Page 92 and 93: Chapter 4 pitting, and intergranula
Page 94 and 95: Chapter 4 The ridged structure, and
Page 96 and 97: Chapter 4 nitric acid is that the b
Page 98 and 99: Chapter 4 Potential (V) Vs Ag/AgCl
Page 100 and 101: Chapter 4 4.2.3 In-situ electrochem
Page 102 and 103: Chapter 4 The surface morphologies
Page 104 and 105: Chapter 4 a b c d Opening up of gra
Page 106 and 107: Chapter 4 Intensity (Arbitrary unit
Page 108 and 109: Chapter 4 The chromium, and oxygen
Page 110 and 111: Chapter 4 Intensity (Arbitrary unit
Page 112 and 113: C H A P T E R5
Page 114 and 115: Chapter 5 elements, and often impar
Page 116 and 117: Chapter 5 5.2 Results and discussi
Page 118 and 119: Chapter 5 Presence of oxygen is due
Page 120 and 121: Chapter 5 was an increase in marten
Page 122 and 123: Chapter 5 formation of Cr 2 N was a
Page 124 and 125: Chapter 5 electrochemical environme
Page 126 and 127: Chapter 5 N + Dose E corr (mV vs. A
Page 128 and 129: Chapter 5 layer capacitance (C dl )
Page 132 and 133: Chapter 5 boundary dissolution was
Page 134 and 135: Chapter 6 C H A P T E R 6
Page 136 and 137: Chapter 6 193]. As a single phase c
Page 138 and 139: Chapter 6 particles range from 8×1
Page 140 and 141: Chapter 6 Results revealed that in
Page 142 and 143: Chapter 6 The change over from capa
Page 144 and 145: Chapter 6 The impedance parameters
Page 146 and 147: Chapter 6 Conc. Substrate condition
Page 148 and 149: Chapter 6 6.6a-d. The uncoated spec
Page 150 and 151: Chapter 6 (55.18°) respectively, w
Page 152 and 153: Chapter 6 OCP shifted in noble dire
Page 154 and 155: Chapter 6 The high phase angle over
Page 156 and 157: Chapter 6 Fig. 6.10d: Log f vs. Log
Page 158 and 159: Chapter 6 Fig. 6.11b: Polarization
Page 160 and 161: Chapter 6 Covalent aspect of lattic
Page 162 and 163: Chapter 6 As compared to uncoated s
Page 164 and 165: Chapter 6 6.2.3.2 Open circuit pote
Page 166 and 167: Chapter 6 Similarly, the plots for
Page 168 and 169: Chapter 6 for the duplex coating, a
Page 170 and 171: Chapter 6 Fig.6.16b: Polarization s
Page 172 and 173: Chapter 6 6.2.3.5 Morphological exa
Page 174 and 175: Chapter 7 C H A P T E R 7 The cha
Page 176 and 177: Chapter 7 1. Surface morphology exa
Page 178 and 179: Chapter 7 6 Duplex Ti-TiO 2 coated
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Chapter 7 EC-SPM study on effect
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[1] Baldev Raj, U. Kamachi Mudali,
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[37] G. Okamoto, T. Shibata, Corros
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[79] M. Moens, M. Van Craen, F.C. A
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[117] R.E.Williford, C.F.Windisch J
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[157] N. Mottu, M. Vayer, R. Erre,
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[197] M. Metikos Hukovic, M. Ceraj
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[19] H. H. Uhlig, Corros Sci, 19 (1
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[57] J. F. Ziegler, J. P. Biersack,
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[97] I. Betova, M. Bojinov, V. Kara
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[139] V. Ashworth, R. P. M. Procter
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[176] G. Frankel, G. Grundmeier, H.
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List of publications 1. Referred
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CHEM02200704003 Nilamadhab Pandhy - Homi Bhabha National ...

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