A study on corrosion behavior of 15CrMo in saturated saline steam with sodium sulfate

Chen

Corrosion Engineering, Science and Technology

et al. 2022

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The experiments were performed to investigate the corrosion behavior of 15CrMo steel in the saline (Na 2 SiO 3 ) water/steam. The samples was analysed using scanning electron microscopy/ energy dispersive spectrum (SEM/EDS) and X-ray diffraction (XRD). The results indicate that the dissolved Na 2 SiO 3 in the steam/liquid phase has obvious effects on the corrosion. In the steam phase, the main corrosion products are crystal NaFe(SiO 3 ) and Fe 3 O 4 . The stick-shaped microstructures (T = 280°C) are gradually converted to acicular-shaped microstructure (T = 320°C). The acicular structures connect with each other under higher temperature (T = 360°C). The relative contents of elemental Fe are 65.65%, 65.39% and 66.5% under the three temperatures, which present little changes. In the liquid phase, the main corrosion product in matrix phase is only NaFe (Si 2 O 6 ) regardless of temperature. The surface is covered by scattered clusters with branches in radical pattern. The clusters accumulated gradually with temperature increasing. The relative content of elemental Fe decreases from 38.11% to 24.69%.

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Section: Resultscontrasting

confidence: 92%

Section: Experimental Apparatus and Parametersmentioning

confidence: 99%

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Effect of temperature on corrosion behaviour of 15CrMo steel in saline (Na₂siO₃) steam/water

Chen

Corrosion Engineering, Science and Technology

et al. 2022

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“…More details about the setup could be referred to in our previous study. [ 32 ] The solution mass added changes according to the experimental temperature. When the temperature inside the autoclave is stabilized at a set value, the steam/water must coexist to maintain the saturation so that superheated vapor would not occur.…”

Section: Methodsmentioning

confidence: 99%

“…In a saturation state, the distribution of salt between steam and water depends on the distribution coefficient. [ 31 ] Bai et al [ 32 ] paid attention to the corrosion characteristic of 15CrMo exposed to saline (Na 2 SO 4 ) steam. Zhu and Zhang [ 33 ] conducted a study of passive film formation on an Fe‐based alloy in a sodium sulfate solution.…”

Section: Introductionmentioning

confidence: 99%

A study on corrosion mechanism of 15CrMo in saline (Na₂SO₄) steam at high temperature

Che

2022

Materials & Corrosion

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To clarify the corrosion mechanism of 15CrMo in saline (Na 2 SO 4 ) steam, the experiments were conducted on a novel setup. The samples were analyzed by scanning electron microscope and X-ray photoelectron spectroscopy. The results indicate that insoluble sulfide, Fe x S y , would form on the gas-phase corroded surface while it would not occur on the liquid-phase corroded surface.The salinity of water/steam has a destructive effect on hydrogen bonds. Compared with deionized steam/water, salinity accelerates the corrosion of steel in two ways electric current intensification in primary cell and energy promotion of the solution system. FeOOH does not change obviously with the increase of salt concentration. The relative variation values of FeOOH content with salt concentration are only 2.43% (gas) and 3.40% (liquid), respectively. Besides, the FeOOH content on the liquid-phase corroded surface is much greater than that on the gas-phase corroded surface regardless of the salt concentration.

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A Comparative Study on Corrosion Behaviors of 15CrMo in Saline (Na2SO4) Gas Phase and Liquid Phase at 350°C

Chen

et al. 2022

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