Effects of laser surface remelting on the molten salt corrosion resistance of yttria-stabilized zirconia coatings

Nickel superalloy Hastelloy-N, alloy X-750, stainless steel 316 (SS316), and stainless steel 304 (SS304) are among the alloys used in the construction of molten salt reactor (MSR). These alloys were analyzed for their corrosion resistance behavior in molten fluoride salt, a coolant used in MSR reactors with 46.5% LiF+ 11.5% NaF+ 42% KF. The corrosion tests were run at 700 °C for 100 h under the Ar cover gas. After corrosion, significant weight loss was observed in the alloy X750. Weight loss registered in SS316 and SS304 was also high. However, Hastelloy-N gained weight after exposure to molten salt corrosion. This could be attributed to electrochemical plating of corrosion products from other alloys on Hastelloy-N surface. SEM–energy-dispersive X-ray spectroscopy (EDXS) scans of cross-section of alloys revealed maximum corrosion damage to the depth of 250 µm in X750, in contrast to only 20 µm on Hastelloy-N. XPS wide survey scans revealed the presence of Fe, Cr, and Ni elements on the surface of all corroded alloys. In addition, Cr clusters were formed at the triple junctions of grains, as confirmed by SEM–EBSD (Electron Back Scattered Diffraction) analysis. The order of corrosion resistance in FLiNaK environment was X750 < SS316 < SS304 < Hastelloy-N.

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Study of Molten Salt Corrosion of Superni-75 using Termogravimetric Technique

Journal of Naval Architecture and Marine Engineering ◽

10.3329/jname.v3i2.922 ◽

1970 ◽

Vol 3 (2) ◽

pp. 77-82 ◽

Cited By ~ 5

Author(s):

TS Sidhu ◽

S Prakash ◽

RD Agrawal

Keyword(s):

Corrosion Resistance ◽

Molten Salt ◽

Hot Corrosion ◽

Corrosion Behaviour ◽

Thick Layer ◽

X Ray Diffraction ◽

Salt Corrosion ◽

Marine Engineering ◽

The Given ◽

Kinetics Of

The present study aims to evaluate the hot corrosion behaviour of the Ni-based alloy Superni- 75 in the molten salt environment of Na2SO-60%V2O5 at 900°C under cyclic conditions. The thermogravimetric technique was used to establish the kinetics of corrosion. X-ray diffraction, scanning electron microscopy/energy-dispersive analysis and electron probe microanalysis techniques were used to analyse the corrosion products. Superni-75 has successfully provided the hot corrosion resistance to the given molten salt environment. The hot corrosion resistance of the Superni-75 has been attributed to the formation of uniform, homogeneous and adherent thick layer of the scale consisting mainly of oxides of nickel and chromium, and refractory Ni(VO3)2. These oxides and refractory nickel vanadates have blocked the penetration of oxygen and other corrosive species to the substrate. Keywords: Hot corrosion, nickel-based alloy, superalloy, molten salt environment DOI: 10.3329/jname.v3i2.922 Journal of Naval Architecture and Marine Engineering 3(2006) 77-82

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Effect of Laser Surface Remelting on the Corrosion Resistance of 316L Orthodontic Brackets

International Journal of Electrochemical Science ◽

10.20964/110402877 ◽

2016 ◽

pp. 2877-2886 ◽

Cited By ~ 1

Author(s):

Xiao-Yan ZHANG ◽

Keyword(s):

Corrosion Resistance ◽

Laser Surface ◽

Orthodontic Brackets ◽

Laser Surface Remelting

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Effects of Laser Processing Parameters on Grain Boundary Character Distribution and Corrosion Resistance of Austenite Stainless Steel

Materials Science Forum ◽

10.4028/www.scientific.net/msf.561-565.2473 ◽

2007 ◽

Vol 561-565 ◽

pp. 2473-2476 ◽

Cited By ~ 3

Author(s):

Sen Yang ◽

Hiroyuki Kokawa ◽

Zhan Jie Wang

Keyword(s):

Stainless Steel ◽

Corrosion Resistance ◽

Laser Processing ◽

Processing Parameters ◽

Laser Surface ◽

304 Stainless Steel ◽

Grain Boundary Character Distribution ◽

Grain Boundary Character ◽

Laser Surface Remelting ◽

Character Distribution

In order to modify grain boundary character distribution (GBCD) and to improve intergranualr corrosion (IGC) resistance of 304 stainless steel, laser surface remelting experiments were conducted on 304 stainless steel using a 2kW CW Nd: YAG laser, and the effects of laser processing parameters on GBCD and corrosion resistance were investigated in detail under the optimal annealing condition (1220K 28h). The experimental results showed that combination of laser surface remelting and the following annealing treatment could change the GBCD remarkably and improve the IGC resistance of 304 stainless steel. However, there are no obvious effects of laser processing parameters on the final depth of the processed zone, although the depth of the molten pool increases with the increase of the laser output power or the decrease of the scanning velocity, and the subsequent GBCD and corrosion resistance.

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