scholarly journals Correlation between Corrosion Rate and Composition of Crystalline Corrosion Products Formed on Weathering Steels

2001 ◽  
Vol 65 (10) ◽  
pp. 922-928 ◽  
Author(s):  
Takayuki Kamimura ◽  
Masato Yamashita ◽  
Hitoshi Uchida ◽  
Hideaki Miyuki
Keyword(s):  
Corrosion Rate ◽  
Corrosion Products

Alloy Design of New Ni-Based Structural Materials for Electrolytic Reduction and its Corrosion Behavior in Lithium Molten Salt

2014 ◽  
Vol 886 ◽  
pp. 41-44 ◽  
Author(s):  
Sang Kyu Park ◽  
Tae Hyuk Lee ◽  
Moon Soo Sim ◽  
Jae Soo Noh ◽  
Soo Haeng Cho ◽  
...  
Keyword(s):  
Corrosion Rate ◽  
Molten Salt ◽  
Corrosion Behavior ◽  
Structural Materials ◽  
Solute Concentration ◽  
Inert Atmosphere ◽  
Electrolytic Reduction ◽  
Corrosion Products ◽  
Alloy Formation ◽  
Lithium Molten Salt

In this study, the corrosion behavior of new Ni-based structural materials was studied for electrolytic reduction after exposure to LiCl-Li2O molten salt at 650°C for 24-216h under an oxidizing atmosphere. The new alloys with Ni, Cr, Al, Si, and Nb as the major components were melted at 1700°C under inert atmosphere. The corrosion products and fine structures of the corroded specimens were characterized by SEM, EDS, and XRD. The corrosion rate of 12wt% Cr-2wt% Si alloys and 12wt% Cr-5wt% Si alloys are below 0.3mm/year. However, the corrosion rate of 20wt% Cr-5wt% Si is 0.6mm/year. Also, the corrosion products of 12wt% Cr alloys were Cr2O3, NiCr2O4, Ni, and NiO; those of 20wt% Cr alloys were Cr2O3, LiAl2Cr3O8, and NiO. The higher corrosion rate of 20wt% Cr-5wt% Si could be the higher solute concentration which leads to an unstable alloy formation. As confirmed by the pseudo binary phase diagram of (Ni-Cr-Al-Nb)-Si, the solubility of the silicon with 20 wt% of Cr decreased to 4 wt% from 5 wt% with 12 wt% of Cr.

Effect of liquid flow velocity on corrosion behavior of 20# steel at initial stage under gas-liquid two-phase plug flow condition

2020 ◽  
Vol 67 (4) ◽  
pp. 415-425
Author(s):  
Guirong Yang ◽  
Wenming Song ◽  
Zibo Zhu ◽  
Ying Ma ◽  
Yuan Hao
Keyword(s):  
Corrosion Rate ◽  
Flow Velocity ◽  
Liquid Flow ◽  
Pipe Wall ◽  
Liquid Velocity ◽  
Plug Flow ◽  
Corrosion Products ◽  
Two Phase ◽  
Content Type ◽  
Corrosion Time

Purpose The paper aims to study the effect of liquid flow velocity on corrosion behavior of 20# steel at initial stage under (CO2/aqueous solution) gas–liquid two-phase plug flow conditions. Design/methodology/approach Weight loss, scanning electron microscopy, energy-dispersive X-ray spectroscopy and XPS methods were used in this study. Findings The corrosion rate increased with the increasing liquid flow velocity at any different corrosion time. The corrosion rate decreased with the extension of corrosion time at the same liquid flow velocity. There was no continuous corrosion products film on the whole pipe wall at any different corrosion time. The macroscopic brown-yellow corrosion products on the pipe wall surface decreased with the increasing liquid flow velocity and the loose floccus corrosion products decreased gradually until these products were transformed into un-continuous needle-like dense products with the increasing liquid velocity. The main elements among the products film were Fe, C and O, and the main phases of products film on the pipe wall were Fe3C, FeCO3, FeOOH and Fe3O4. When the corrosion time was 1 h under different liquid–velocity condition, the thickness of local corrosion products film was from 3.5 to 3.8 µm. Originality/value The ion mass transfer model of corrosion process in pipe was put forward under gas–liquid two-phase plug flow condition. The total thickness of diffusion sublayer and turbulence sublayer decreased as well as the turbulence propagation coefficient increased with the increasing liquid velocity, which led to the increasing velocity of ion transfer during corrosion process. This was the fundamental reason for the increase of corrosion rate with the increasing liquid velocity.

Effect of Temperature and H2S Concentration on Corrosion of X52 Pipeline Steel in Acidic Solutions

2013 ◽  
Vol 743-744 ◽  
pp. 589-596 ◽  
Author(s):  
Meng Liu ◽  
Jian Qiu Wang ◽  
Wei Ke
Keyword(s):  
Corrosion Rate ◽  
Pipeline Steel ◽  
Corrosion Products ◽  
Effect Of Temperature ◽  
Corrosion Mechanism ◽  
General Corrosion ◽  
Ferrous Sulfide ◽  
Immersion Corrosion ◽  
Different Temperatures ◽  
Diffraction Patterns

The corrosion behavior of X52 pipeline steel in H2S solutions was investigated through immersion corrosion test which was carried out in a high temperature and high pressure autoclave at different temperatures and H2S concentrations. General corrosion rates were calculated based on the weight loss of samples. The morphology and the chemical composition of the corrosion products were obtained by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). The crystal structure of corrosion products was analyzed by X-Ray diffraction patterns (XRD). The corrosion products consisted mainly of the sulfide compounds (mackinawite, cubic ferrous sulfide, troilite and pyrrhotite). The corrosion products included two layers: the inner iron-rich layer and the outer sulfur-rich layer. Under H2S concentrations of 27g/L, the corrosion rate increased with the increase of temperature up to 90°C and then decreased at 120°C, finaly increased again. The corrosion rate first increased with H2S concentrations then decreased at 120°C. The structure and stability of the corrosion products due to different corrosion mechanism had a major impact on the corrosion rate. The corrosion resistance of the corrosion products increased as follows: mackinawite < cubic ferrous sulfide < troilite < pyrrhotite.

Early Corrosion Behavior of Pipeline Steel Containing 1% Cr in Sea Water Environment

2015 ◽  
Vol 1120-1121 ◽  
pp. 773-778
Author(s):  
Zhen Guang Liu ◽  
Xiu Hua Gao ◽  
Lin Xiu Du ◽  
Jian Ping Li ◽  
Ping Ju Hao
Keyword(s):  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Sea Water ◽  
Pipeline Steel ◽  
Water Environment ◽  
Corrosion Products ◽  
Immersion Experiment ◽  
Three Stages ◽  
Stage 1 ◽  
Microscopic Surface

The corrosion behavior of pipeline steel containing 1%Cr is studied by using immersion experiment. The corrosion rust is characteried with macroscopic/microscopic surface morphology, corrosion kinetics and corrosion phases. The results demonstrate that the main corrosion products are lepidocrocite and goethite, Cr-rich compound consists of the inner layer. The corrosion process could be divided into three stages. At stage 1, the corrosion rate decreases fast, and the distributed corrosion products are formed. At stage 2, the granular corrosion products appear on coupons surface gradually, and a plain corrosion rate is obtained. At stage 3, a compact and dense corrosion layer attaches to coupons surface, and corrosion rate decreases mildly.

The Relation between Corrosion Rate and Corrosion Products from Low Carbon Steel

2000 ◽  
Vol 220 (1) ◽  
pp. 351-356 ◽  
Author(s):  
A.L. Morales ◽  
D. Cartagena ◽  
J.L. Rendón ◽  
A. Valencia
Keyword(s):  
Carbon Steel ◽  
Corrosion Rate ◽  
Low Carbon Steel ◽  
Corrosion Products ◽  
Low Carbon

scholarly journals Corrosion rate and corrosion behaviour analysis of carbon steel pipe at constant condensed fluid

10.30544/591 ◽  
2021 ◽  
Author(s):  
Ahmad Royani ◽  
Siska Prifiharni ◽  
Gadang Priyotomo ◽  
Sundjono Sundjono
Keyword(s):  
Carbon Steel ◽  
Corrosion Rate ◽  
Corrosion Behaviour ◽  
Low Carbon Steel ◽  
Exposure Period ◽  
Xrd Analysis ◽  
Quality Parameters ◽  
Corrosion Products ◽  
Steel Pipe ◽  
Low Carbon

This study investigates the corrosion rate and corrosion behavior of carbon steel pipe at constant condensed fluid from a geothermal power plant. The corrosion rate of the steel was determined by weight loss analysis, whereas the corrosivity of the condensate fluids was measured by a multimeter Hach HQ40d. The morphology of the corrosion products formed was characterized by scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), and x-ray diffraction (XRD) analysis. Results showed that the corrosion rate in the liquid part of the condensate fluids is constant during the immersion period when water quality parameters are constant. Meanwhile, the corrosion rate of low carbon steel pipe decreases though with the longer exposure period in the condensate fluid. The decrease of metal corrodibility identical to the lower corrosion rate at a longer exposure time due to the protective corrosion layer formed. The corrosion products during immersion tests identified in the corrosion test were uniform with iron oxide in the form of FeO(OH) and Fe2O3*H2O.

scholarly journals Corrosion Behavior of 3% Cr Casing Steel in CO2-Containing Environment: A Case Study

2018 ◽  
Vol 11 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Lin Xu ◽  
Jie Xu ◽  
Ming-biao Xu ◽  
Si-yang Li ◽  
Shuai Liu ◽  
...  
Keyword(s):  
Corrosion Rate ◽  
Corrosion Product ◽  
Corrosion Behavior ◽  
Exposure Time ◽  
Corrosion Products ◽  
Localized Corrosion ◽  
Internal Corrosion ◽  
Tafel Polarization ◽  
Water Cut ◽  
Increasing Temperature

Introduction: The production casing of 3% Cr steel has encountered severe internal corrosion in Huizhou Oilfield. To disclose corrosion behavior of inner casing, a series of corrosion exposure tests were systematically conducted on 3% Cr coupons in terms of in-field conditions. Material and Methods: Influence of exposure time, temperature, and water-cut on the CO2 corrosion of 3% Cr steel was investigated, and analyses on weight loss, composition and morphology of corrosion product, and Tafel polarization curves were further carried out. Result: The results showed that the corrosion rate of 3% Cr steel increased with increasing temperature, but such trend descended when the temperature exceeded 65°C due to formation of an compact and adherent corrosion product film on the surface of 3% Cr coupons. While varying exposure time from 7 days to 14 days, the corrosion rate decreased, and the Cr and O enrichment was determined in the corrosion products. The corrosion rate of 3% Cr steel increased with a continuous increment of water-cuts, especially when the water-cut was larger than 40%. Conclusion: The localized corrosion can happen at the lower water-cut due to the presence of amorphous films. The main corrosion products were FeCO3, Cr5O12, Fe2O3, and Fe-Cr. Entry of CO2 to the simulated formation water caused an increase in the anodic Tafel slope, and accelerated dissolution of 3% Cr steel.

Microbiologically Influenced Corrosion Combined with Under-Deposit Corrosion Mechanism and Control Technology in Water Injection Wells of Middle East Carbonate Oilfield

2021 ◽  
Author(s):  
Zhengrong Ye ◽  
Huachang Chi ◽  
Xiang Zhou ◽  
Zhiwen Yang ◽  
Weidong Jiang ◽  
...  
Keyword(s):  
Middle East ◽  
Corrosion Rate ◽  
High Salinity ◽  
Water Injection ◽  
Corrosion Products ◽  
Microbiologically Influenced Corrosion ◽  
Corrosion Mechanism ◽  
Corrosion Prevention ◽  
High Hydrogen ◽  
Corrosion Failure

Abstract A carbonate oilfield in the Middle East carries out the mixed water injection of produced water and fresh water, after 1 year of its rapid exploration. The injected water is highly corrosive, with high salinity, high chloride concentration and high hydrogen sulfide. Recently, there are dozens of corrosion perforations on L80 tubing in injectors within 2 years in the field and the corrosion rate reaches 3.6 mm/a. After the tubing leaks, the injected water enters into the annulus between the tubing and casing, which causes casing corrosion, damages the well integrity, and greatly influences the field production. In this paper, the causes for such rapid tubing corrosion failure are investigated by using optical metallographic microscopy, scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) X-ray diffraction (XRD), and combined with the weight loss and bacteria testing. Firstly, test the element composition of the L80 tubing to verify the tubing quality. Secondly, conduct the corrosion experiments of H2S and dissolved oxygen. Thirdly, analyze the morphology and corrosion product composition of failure tubing. The results indicate that the failed L80 tubing material meets the requirements of API SPEC 5CT-2011 standard. The localized corrosion rate of L80 is 0.293~0.697 mm/a at whole well depth in the simulated injection water. Bacteria were detected in both the injected water and the corrosion products of the failed tubing. In addition, the corrosion products of failed tubing are mainly FeS, CaCO3 and Fe3O4, which indicates that the synergistic effect of microbiologically influenced corrosion and under-deposited corrosion promote the perforation of tubing. Then the corrosion prevention strategy of UHMWPE lined tubing was proposed. UHMWPE lined tubing has been applied in nine water injectors. After one year and a half, one of the water injector’s UHMWPE lined tubing has been detected, no corrosion perforations observed, and the scale deposition became slightly. This case provides useful practical experience for corrosion prevention of high salinity and high acid injection well in carbonate oilfields.

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