A multi-dimensional non-uniform corrosion model for bioabsorbable metallic vascular stents

2021 ◽  
Author(s):  
Weiliang Shi ◽  
Hongxia Li ◽  
Kellen Mitchell ◽  
Cheng Zhang ◽  
Tingzhun Zhu ◽  
...  
Keyword(s):  
Uniform Corrosion ◽  
Vascular Stents ◽  
Corrosion Model

A Multi-Dimensional Non-Uniform Corrosion Model for Bioabsorbable Metallic Vascular Stents

2020 ◽  
Author(s):  
Weiliang Shi ◽  
Hongxia Li ◽  
Kellen Mitchell ◽  
Cheng Zhang ◽  
Tingzhun Zhu ◽  
...  
Keyword(s):  
Uniform Corrosion ◽  
Vascular Stents ◽  
Corrosion Model

Mechanistic Modeling of Carbon Steel Corrosion in a Methyldiethanolamine (MDEA)-Based Carbon Dioxide Capture Process

CORROSION ◽  
10.5006/0695 ◽  
2013 ◽  
Vol 69 (6) ◽  
pp. 551-559 ◽  
Author(s):  
Yoon-Seok Choi ◽  
Deli Duan ◽  
Shengli Jiang ◽  
Srdjan Nešić
Keyword(s):  
Carbon Dioxide ◽  
Carbon Steel ◽  
Model Development ◽  
Electrochemical Corrosion ◽  
Steel Corrosion ◽  
Mechanistic Modeling ◽  
Uniform Corrosion ◽  
Capture Process ◽  
Corrosion Model ◽  
Carbon Dioxide Co2

A predictive model was developed for corrosion of carbon steel in carbon dioxide (CO2)-loaded aqueous methyldiethanolamine (MDEA) systems, based on modeling of thermodynamic equilibria and electrochemical reactions. The concentrations of aqueous carbonic and amine species (CO2, bicarbonate [HCO3−], carbonate [CO32−], MDEA, and protonated MDEA [MDEAH+]) as well as pH values in the MDEA solution were calculated. The water chemistry model showed a good agreement with experimental data for pH and CO2 loading, with an improved correlation upon use of activity coefficients. The electrochemical corrosion model was developed by modeling polarization curves based on the given species's concentrations. The required electrochemical parameters (e.g., exchange current densities, Tafel slopes, and reaction orders) for different reactions were determined from experiments conducted in glass cells. Iron oxidative dissolution, HCO3− reduction, and MDEAH+ reduction reactions were implemented to build a comprehensive model for corrosion of carbon steel in an MDEA-CO2-water (H2O) environment. The model is applicable to uniform corrosion when no protective films are present. A solid foundation is provided for corrosion model development for other amine-based CO2 capture processes.

scholarly journals Progressive Collapse Analysis of an FPSO Vessel Hull Girder Under Vertical Bending Considering Different Corrosion Models

2020 ◽  
Author(s):  
Zorareh Nouri ◽  
Mohammad Reza Khedmati
Keyword(s):  
Ultimate Strength ◽  
Pitting Corrosion ◽  
Progressive Collapse ◽  
Relative Reduction ◽  
Uniform Corrosion ◽  
Hull Girder ◽  
Operational Life ◽  
Collapse Analysis ◽  
Corrosion Model ◽  
Progressive Collapse Analysis

Abstract Nowadays, with the increasing operational life of ships, the aging effects on their structural behavior need to be investigated precisely. With the corrosive marine environment taken into consideration, one of the important effects of aging that must be studied is thickness degradation. In this paper, with the use of previously proposed equivalent thickness formulations for corroded plates, the progressive collapse analysis software HULLST is enhanced, and then, the effects of different corrosion models of uniform, random, pitting, and tanker pattern types on the ultimate and residual strengths of a floating production, storage, and offloading vessel hull girder are evaluated for the ages of 0 to 25 years. Results reveal that the uniform corrosion and random corrosion models have close outcomes. The value of relative reduction in the ultimate strength of ship hull girder (compared with the intact condition) ranges roughly from 6% for the age of 5 years to 17% for the age of 25 years in the hogging mode. The relative reduction in the ultimate strength ranges from 4% to 16% in the sagging mode. Pitting corrosion and tanker pattern (random) corrosion models lead to higher relative reductions in ultimate strength. The pitting corrosion model leads to a 16%–32% relative reduction in the ultimate strength for the ages of 5–25 years of the ship in either hogging or sagging. The tanker pattern (random) corrosion model leads to a 6%–37% relative reduction in the ultimate strength in the hogging mode and 3%–31% in the sagging mode at ship ages of 5 to 25 years.

Vascular stents

1999 ◽  
Vol 36 (12) ◽  
pp. 909-1053
Author(s):  
M AMATTOS ◽  
K HODGSON ◽  
S HURLBERT ◽  
J HENRETTA ◽  
Y STERNBACH ◽  
...  
Keyword(s):  
Vascular Stents

scholarly journals In Vitro Degradation of Absorbable Zinc Alloys in Artificial Urine

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 295 ◽  
Author(s):  
Sébastien Champagne ◽  
Ehsan Mostaed ◽  
Fariba Safizadeh ◽  
Edward Ghali ◽  
Maurizio Vedani ◽  
...  
Keyword(s):  
Surface Characterization ◽  
Urinary Tract Obstruction ◽  
Calcium Content ◽  
Corrosion Layer ◽  
Uniform Corrosion ◽  
In Vitro Degradation ◽  
Pure Zinc ◽  
Zinc Alloys ◽  
Artificial Urine

Absorbable metals have potential for making in-demand rigid temporary stents for the treatment of urinary tract obstruction, where polymers have reached their limits. In this work, in vitro degradation behavior of absorbable zinc alloys in artificial urine was studied using electrochemical methods and advanced surface characterization techniques with a comparison to a magnesium alloy. The results showed that pure zinc and its alloys (Zn–0.5Mg, Zn–1Mg, Zn–0.5Al) exhibited slower corrosion than pure magnesium and an Mg–2Zn–1Mn alloy. The corrosion layer was composed mostly of hydroxide, carbonate, and phosphate, without calcium content for the zinc group. Among all tested metals, the Zn–0.5Al alloy exhibited a uniform corrosion layer with low affinity with the ions in artificial urine.

scholarly journals Investigation of Corrosion Rate and Rust Expansion Form of Segment Reinforcement for Shield Tunnel by Combined Action of Soil Loading, Chloride Ion and Stray Current

2021 ◽  
Vol 13 (6) ◽  
pp. 3444
Author(s):  
Zheng Li ◽  
Hao Jin ◽  
Shuo Yu
Keyword(s):  
Corrosion Rate ◽  
Steel Corrosion ◽  
Chloride Ion ◽  
Shield Tunnel ◽  
Uniform Corrosion ◽  
Stray Current ◽  
Soil Loading ◽  
Capacity Degradation ◽  
Expansion Form ◽  
Combined Action

Segment reinforcement corrosion can cause bearing-capacity degradation of shield tunnel, which is unsafe for the metro operation. Therefore, a three-dimensional computational model was proposed in this paper to study the corrosion rate and rust expansion form of segment reinforcement by the combined action of soil loading, chloride ion and stray current. The results show that the arch waist segment steel corrosion rate in the middle is larger than the ends. The rust expansion form of segment reinforcement appears be an eccentric circle. The radius size and circular center are related to the non-uniform corrosion coefficient and the maximum corrosion current density.

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