Effect of Laser Fusing on Hot Corrosion Resistance of Nickel Based Self Fluxing Alloy Coating

2006 ◽  
Vol 522-523 ◽  
pp. 385-392
Author(s):  
Yu Li ◽  
Kazumasa Nishio ◽  
Mitsuaki Katoh ◽  
Tomiko Yamaguchi ◽  
Shinji Okamine
Keyword(s):  
Corrosion Resistance ◽  
Hot Corrosion ◽  
Fossil Fuel ◽  
Waste Incineration ◽  
Alloy Coating ◽  
Mixed Salt ◽  
Excellent Corrosion Resistance ◽  
Sprayed Coatings ◽  
Unmelted Particles ◽  
Thermal Sprayed Coatings

The thermal sprayed coatings are widely used in waste incineration boilers and fossil fuel-fired boilers. However, the defects, such as porosity, cracks and unmelted particles, in these coatings are detrimental to corrosion performance. In this study, the nickel based self fluxing alloy coating was fused by YAG laser to improve hot corrosion resistance of the coating. Under appropriate laser parameters, the nonporous, crack-free coating was produced. Hot corrosion test, conducted in the presence of a mixed salt of Na2SO4/NaCl/KCl at 550Гshowed that the modified coating exhibited excellent corrosion resistance compared with the as sprayed and gas fused coatings.

Microstructure and Properties of Laser Fused Nickel Based Self Fluxing Alloy Coating

2006 ◽  
Vol 15-17 ◽  
pp. 135-140
Author(s):  
Yu Li ◽  
Kazumasa Nishio ◽  
Mitsuaki Katoh ◽  
Tomiko Yamaguchi
Keyword(s):  
Fossil Fuel ◽  
Wear Test ◽  
Waste Incineration ◽  
Alloy Coating ◽  
Improve Performance ◽  
Mixed Salt ◽  
Wear And Corrosion ◽  
Sprayed Coatings ◽  
Unmelted Particles ◽  
Thermal Sprayed Coatings

The thermal sprayed coatings are widely used in waste incineration boilers and fossil fuel-fired boilers. However, the defects, such as porosity, cracks and unmelted particles, in these coatings are detrimental to corrosion performance. In this study, the nickel based self fluxing alloy coating was fused by YAG laser to improve performance of the coating. Under appropriate laser parameters, the nonporous, crack-free coating was produced. The rubber wheel type abrasion wear test and hot corrosion test conducted in the presence of a mixed salt of Na2SO4/NaCl/KCl at 650°C showed that the modified coating exhibited excellent wear and corrosion resistances compared with the as sprayed and gas fused coatings.

Thermal sprayed coatings for hot corrosion protection of exhaust valves in naval diesel engines

2016 ◽  
Vol 295 ◽  
pp. 78-87 ◽  
Author(s):  
L. Baiamonte ◽  
F. Marra ◽  
S. Gazzola ◽  
P. Giovanetto ◽  
C. Bartuli ◽  
...  
Keyword(s):  
Corrosion Protection ◽  
Diesel Engines ◽  
Hot Corrosion ◽  
Exhaust Valves ◽  
Sprayed Coatings ◽  
Thermal Sprayed Coatings

Hot Corrosion Behavior of Sputtered Fe-Y Alloy Coatings with Different Y Contents

2011 ◽  
Vol 391-392 ◽  
pp. 1263-1267
Author(s):  
Guang Yan Fu ◽  
Jing Yu Chen ◽  
Qun Liu ◽  
Yong Su
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Hot Corrosion ◽  
Alloy Coating ◽  
Good Adhesion ◽  
Corrosion Scale ◽  
Measurement Results ◽  
The Matrix ◽  
Better Than

Three Fe-Y alloy coatings with differernt kinds of Y contents were prepared on stainless steel by magnetron sputtering. The hot corrosion behavior of sputtered alloy coatings with Na2SO4 deposits at 800 °C was investigated by discontinuous weigh measurement. Results show that the sputtered Fe-Y alloy coatings exhibit good adhesion with the matrix of stainless steel, and the hot corrosion kinetic curves of the specimens approximately follow the parabolic rate law. The Fe oxides are the main substances in the corrosion scale, and the hot corrosion rate of the three Fe-Y alloy coatings increases as the Y content increases. Therefore, the hot corrosion resistance of Fe-15Y alloy coating is better than that of Fe-20Y or Fe-30Y alloy coating.

Hot Corrosion of NiCrAlY/(ZrO2-CeO2-Y2O3) Composite Coatings in NaCl-Na2SO4 Molten Salt

2010 ◽  
Vol 658 ◽  
pp. 228-231 ◽  
Author(s):  
Jae Ho Lee ◽  
Dong Bok Lee
Keyword(s):  
Corrosion Resistance ◽  
Molten Salt ◽  
Hot Corrosion ◽  
Ceramic Composite ◽  
Composite Coatings ◽  
Air Plasma Spray ◽  
Air Plasma ◽  
Coating Surface ◽  
Metal Ceramic ◽  
Sprayed Coatings

The metal/ceramic composite coatings that consisted of (Ni-22Cr-10Al-1Y) and (ZrO2-25CeO2-2.5Y2O3) were prepared by the air plasma spray (APS) method. The as-sprayed coatings consisted of metal-rich and ceramic-rich regions, between which the -Al2O3 oxide stringers existed owing to the oxidation of Al in (Ni-22Cr-10Al-1Y) during APS. The composite coatings were hot corroded at 800 and 900 oC for up to 50 h in 75%NaCl-25%Na2SO4 molten salt. The corrosion products that formed on the coating surface during hot corrosion were mostly dissolved off into the molten salt. The scales that remained on the coating surface consisted primarily of Cr2O3, and a lesser amount of NiO and Al2O3. The corrosion resistance decreased, as not only the test temperature and time but also the amount of metal in the coating increased.

scholarly journals Hot Corrosion Resistance of Laser-Sealed Thermal-Sprayed Cermet Coatings

Coatings ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 347 ◽  
Author(s):  
Lidia Baiamonte ◽  
Cecilia Bartuli ◽  
Francesco Marra ◽  
Annamaria Gisario ◽  
Giovanni Pulci
Keyword(s):  
Corrosion Resistance ◽  
Hot Corrosion ◽  
Gas Turbines ◽  
Surface Hardness ◽  
Cermet Coatings ◽  
Nickel Chromium ◽  
Sprayed Coatings ◽  
Power Diode ◽  
High Power Diode Laser ◽  
Type Ii Hot Corrosion

Hot corrosion affects the components of diesel engines and gas turbines working at high temperatures, in the presence of low-melting salts and oxides, such as sodium sulfate and vanadium oxide. Thermal-sprayed coatings of nickel–chromium-based alloys reinforced with ceramic phases, can improve the hot corrosion and erosion resistance of exposed metals, and a sealing thermal, post-treatment can prove effective in reducing the permeability of aggressive species. In this study, the effect of purposely-optimized high-power diode laser reprocessing on the microstructure and type II hot corrosion resistance of cermet coatings of various compositions was investigated. Three different coatings were produced by high velocity oxy-fuel and was tested in the presence of a mixture of Na2SO4 and V2O5 at 700 °C, for up to 200 h: (i) Cr3C2–25% NiCr, (ii) Cr3C2–25% CoNiCrAlY, and (iii) mullite nano–silica–60% NiCr. Results evidenced that laser sealing was not effective in modifying the mechanism, on the basis of the hot corrosion degradation but could provide a substantial increase of the surface hardness and a significant decrease of the overall coating material consumption rate (coating recession), induced by the high temperature corrosive attack.

Hot-corrosion behavior of Ti3SiC2in a eutectic mixture of LiCl–KCl salts in air

RSC Advances ◽  
2015 ◽  
Vol 5 (28) ◽  
pp. 21629-21633
Author(s):  
Ning Wang ◽  
Changming Cheng ◽  
Jie Tian ◽  
Sheng Hu ◽  
Haibin Zhang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Hot Corrosion ◽  
Eutectic Mixture ◽  
Protective Layer ◽  
Excellent Corrosion Resistance

Ti3SiC2exhibits excellent corrosion resistance at 550 °C and forms an oxide protective layer at 650 °C and 750 °C.

Improvement of Corrosion Resistance of Dissimilar Welded Joints in VVER Secondary Circuit

2019 ◽  
Vol 5 (3) ◽  
Author(s):  
Petr Samek ◽  
Ondřej Chocholatý ◽  
Zdeněk Čančura ◽  
Antonín Kříž
Keyword(s):  
Corrosion Resistance ◽  
Service Life ◽  
Welded Joints ◽  
Power Reactor ◽  
Experimental Program ◽  
Secondary Circuit ◽  
Water Power ◽  
Degradation Processes ◽  
Sprayed Coatings ◽  
Thermal Sprayed Coatings

This article presents experimental program, focused on extending lifetime and operation reliability of dissimilar welded joints of austenitic and perlite steel in conditions of secondary circuit media of water–water power reactor (VVER) unit. The main purpose of this experimental program is to bring new possibilities of corrosion protection of dissimilar welded joints, which are threatened by corrosion and degradation processes. These degradation processes significantly affect their service life. Suitability and corrosion behavior of thermal-sprayed coatings were tested.

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