Corrosion Behavior of Incoloy 825 in High Temperature Vapor Containing Sodium Chloride

2018 ◽  
Vol 278 ◽  
pp. 102-106
Author(s):  
Jian Qiao Yang ◽  
Shu Zhong Wang ◽  
Dong Wang ◽  
Jian Na Li ◽  
Dong Hai Xu
Keyword(s):  
High Temperature ◽  
Sodium Chloride ◽  
Corrosion Behavior ◽  
Outer Layer ◽  
Layer Structure ◽  
Sample Surface ◽  
High Concentration ◽  
Fine Grain ◽  
Incoloy 825 ◽  
High Temperature Vapor

Corrosion behavior of Incoloy 825 was studied in high temperature vapor with high concentration of NaCl. After 80 h exposure, a bi-layer structure was formed on sample surface after exposure. The outer layer is consisted of loose and large-grain oxides, and the inner layer is composed of fine-grain oxide. The whole layer was identified to be CrOOH/Fe3O4/Cr2O3/Incoloy 825 from outer to inner.

scholarly journals The Fouling Behavior of Steam Generator Tube at Different Positions in the High-Temperature Water

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 684
Author(s):  
Tong Zhang ◽  
Guihui Qiu ◽  
Hongying Yu ◽  
Peng Zhou ◽  
Shicheng Wang ◽  
...  
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Steam Generator ◽  
Outer Layer ◽  
Layer Structure ◽  
Steam Generator Tube ◽  
Support Plate ◽  
High Temperature Water ◽  
Triple Layer ◽  
Temperature Water

The fouling behavior of a steam generator (SG) tube was investigated at different positions after 500 h of immersion in high-temperature water. A triple-layer structure of fouling appeared at both the crevice position and the free span position, namely, the large, dispersedly distributed deposition layer on the top; the small and faceted outer layer; and the relatively continuous inner layer. There was no obvious positional effect on the thickness of the inner layer. However, in the crevice position, the density of the deposited particle and the thickness of the outer layer was much higher than those of the free span position. The tube support plate (TSP) made of 410 stainless steel contributed significantly to the fouling behavior of the SG tube in the crevice between the SG tube and the TSP.

Analysis on the Structure and Mechanism of Cracking and Spalling for Super304H Steel Oxide Films in High-Temperature Steam

2014 ◽  
Vol 908 ◽  
pp. 72-76 ◽  
Author(s):  
Yan Hui Li ◽  
Shu Zhong Wang ◽  
Xue Dong Li ◽  
Meng Meng Ren
Keyword(s):  
High Temperature ◽  
Outer Layer ◽  
Layer Structure ◽  
Spinel Phase ◽  
Oxide Films ◽  
Primary Component ◽  
Steel Matrix ◽  
X Ray Diffraction ◽  
High Temperature Steam ◽  
Super304h Steel

In this paper, by means of Scanning Electronic Microscope (SEM), X-ray diffraction analyzer (XRD) and Cross hatch scanning analysis, the Structure and mechanism of cracking and spalling for Super304H steel oxide films in high temperature steam were investigated. With the oxidation proceeding, the surface of Super304H steel specimens is covered by a large amount of tiny holes, which causes the occurrence of an outer oxide layer. The Super304H oxide film generally has a double-layer structure: the outer layer mainly for iron oxide Fe3O4, also being covered by a small amount of Fe2O3, and the inner layer with the FeCr2O4 spinel phase as primary component. Because of the inhomogeneity of oxide distribution, large amounts of smaller gaps appear in the Super304H steel oxide films. Due to the differences among the outer layer, the inner layer and steel matrix in thermal expansion coefficient, when the steam temperature around the specimen changes periodically, the stress variation arise in the Super304H steel and oxide films, which causes the cracking and spalling of oxide films.

scholarly journals Comparison of the corrosion behavior and surface morphology of NiTi alloy and stainless steels in sodium chloride solution

2016 ◽  
Vol 52 (1) ◽  
pp. 53-61 ◽  
Author(s):  
S. Kozuh ◽  
L. Vrsalovic ◽  
M. Gojic ◽  
S. Gudic ◽  
B. Kosec
Keyword(s):  
Stainless Steel ◽  
Sodium Chloride ◽  
Corrosion Behavior ◽  
Stainless Steels ◽  
Electrochemical Impedance ◽  
Layer Structure ◽  
Niti Alloy ◽  
Surface Film ◽  
Open Circuit ◽  
Aisi 316L

The corrosion behavior of NiTi alloy and stainless steels (AISI 316L and X2CrNiMoN22-5-3) in 0.9% sodium chloride (0.154 moll-1) solution was investigated using open circuit potential measurements, potentiodynamic polarization and electrochemical impedance spectroscopy measurements. Microstructural analyses before and after electrochemical tests were performed with the scanning electron microscopy (SEM) equipped with energy dispersive spectrometry (EDS). The lowest corrosion current density has NiTi alloy and the extent of the passive range increased in the order AISI 316L stainless steel < NiTi alloy < X2CrNiMoN22-5-3 duplex stainless steel. The oxide film formed on all samples has a double-layer structure consisting of a barrier-type inner layer and a porous outer layer. Oxide films formed on the surface of steels mainly contains iron oxides and chromium oxide, while the surface film of the NiTi alloy mainly contains TiO2 oxide.

Microstructure and High-Temperature Oxidation-Resistant Performance of Several Silicide Coatings on Nb-Ti-Si Based Alloy Prepared by Pack Cementation Process

2012 ◽  
Vol 533 ◽  
pp. 145-165
Author(s):  
Jing Li ◽  
Xi Ping Guo
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
Outer Layer ◽  
High Temperature Oxidation ◽  
Layer Structure ◽  
Middle Layer ◽  
Alloy Coating ◽  
Deposition Process ◽  
Temperature Oxidation ◽  
Oxidation Resistant

The microstructure and high-temperature oxidation-resistant performance of several silicide coatings on an Nb-Ti-Si based alloy were revealed in the present work. These silicide coatings were prepared respectively at 1250°C for 8 h by pack siliconizing process, Si-Y co-deposition process and Si-Al-Y co-deposition process (with different Al contents in the packs). The results showed that the purely siliconized coating was composed of a (Ti,Nb)5Si3 ouer layer, a (Nb,X)Si2 (X represents Ti, Cr and Hf elements) middle layer and a (Ti,Nb)5Si4 inner layer. A thicker and more compact double-layer structure including a (Nb,X)Si2 outer layer and a (Ti,Nb)5Si4 inner layer was observed in the Si-Y co-deposition coating. In addition, a higher Y content (about 0.34 at. %) in the outer layer of the Si-Y co-deposition coating was obtained, while the Y content was only about 0.06 at. % in the purely siliconized coating. The Si-Al-Y co-deposition coating possessed a (Nb,X)Si2 outer layer, a (Ti,Nb)5Si4 middle layer and an Al, Cr-rich inner layer. A suitable addition of Al powders (5 wt. %) in the packs was beneficial to thicken the (Nb,X)Si2 outer layer, while a sharp reduction in the coating thickness was found when excess Al powders (10 wt. %) was added in the packs. However, compared with the former coating, the later coating prepared with more Al powders in the packs resulted in a slight increase in the content of Al and Y in the (Nb,X)Si2 outer layer from about 0.21 and 0.54 at. % to 0.87 and 0.79 at. % respectively. The thickness and microstructure of the scales formed on above four coatings upon oxidation at 1250°C for either 5 h or 100 h were comparatively investigated. The oxidation resistance of these silicide-type coatings was notably enhanced by the addition of Y and Al. The Si-Al-Y co-deposition coating, which was prepared with 5 wt. % Al powders in the pack, possessed the best oxidation resistance due to its optimum dense and continuous scale and compact coating remained. Keywords: Nb-Ti-Si based alloy; coating; microstructure; oxidation-resistant perfor-mance *Corresponding author. Tel./fax: +86 29 88494873. E-mail address: [email protected] (X. Guo).

scholarly journals Use of sodium chloride and zeolite during shipment of Ancistrus triradiatus under high temperature

2011 ◽  
Vol 9 (4) ◽  
pp. 909-914 ◽  
Author(s):  
Wilson F. Ramírez-Duarte ◽  
Carolina Pineda-Quiroga ◽  
Nhora Martínez ◽  
Pedro R. Eslava-Mocha
Keyword(s):  
Water Quality ◽  
High Temperature ◽  
Sodium Chloride ◽  
Dissolved Oxygen ◽  
High Temperatures ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
High Concentration ◽  
Before And After ◽  
Total Ammonia

The use of sodium chloride (0.5 g/L and 1 g/L) and zeolite (22.7 g/L) during shipment (48 h) of Ancistrus triradiatus at high temperatures (between 24.5 and 34ºC) were evaluated. Several water quality parameters (dissolved oxygen, pH, conductivity, and total ammonia) were measured before and after shipment. Glycemia was measured before shipment and at 24 and 48 h after shipment. After shipment, a resistance test was carried out in a high concentration of sodium chloride, and mortality was recorded after shipment, and 7 days post-shipment. While the two evaluated substances increased survival of A. triradiatus challenged by high temperatures during shipment, the best result was obtained with 1 g/L of sodium chloride.

Influence of Chromium on CO2/H2S Corrosion Behavior of X100 Grade Pipeline Steel

2013 ◽  
Vol 662 ◽  
pp. 309-314
Author(s):  
Jun Sheng Zhang ◽  
Hui Bin Wu ◽  
Li Dong Wang ◽  
Di Tang ◽  
Li Fu Liu
Keyword(s):  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Outer Layer ◽  
Chromium Content ◽  
Layer Structure ◽  
Pipeline Steel ◽  
High Grade ◽  
Cr Content ◽  
Corrosion Rates ◽  
Corrosion Scale

Four kinds of X100 grade pipeline steels containing different chromium content were designed and corrosion behavior were studied in order to confirm the influence of Cr on the properties of high grade pipeline steel. The corrosion experiments demonstrated that Corrosion rates of Four steels in the experiment decrease with the increasing of Cr content, and the scales on the four steels have a two-layer structure under the corrosion of CO2 and H2S. The outer layer is mainly composed of FeS or FeS1-x and the inner layer consisted of FeCO3. Cr enriches in the inner layer and Cr content of the inner layer increases with the Cr content in matrix. The Cr enrichment enhanced the compactness of the scales further hindered the diffusion of ions from liquid to the surface of steel. The corrosion scale with Cr(OH)3 is anion-selective and reduce the amount of anion reaches metal surface, thus reducing corrosion rate.

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