Cumulative damage function model for prediction of uniform corrosion rate of metals in atmospheric corrosive environment

2004 ◽  
Vol 39 (4) ◽  
pp. 313-320 ◽  
Author(s):  
S. Bhaskar ◽  
Nagesh R. Iyer ◽  
J. Rajasankar
Keyword(s):  
Corrosion Rate ◽  
Damage Function ◽  
Cumulative Damage ◽  
Uniform Corrosion ◽  
Corrosive Environment ◽  
Function Model

Corrosion Behavior and Safety Analysis of 80S Steel in H2S/CO2 Environment

2019 ◽  
Vol 944 ◽  
pp. 862-866
Author(s):  
Yong Qiang Zhang ◽  
Zhi Gang Yang ◽  
Rui Min Gao ◽  
Li Liu ◽  
Zhi Fu Yin ◽  
...  
Keyword(s):  
Corrosion Rate ◽  
Corrosion Test ◽  
The Other ◽  
Test Duration ◽  
Uniform Corrosion ◽  
Corrosive Environment ◽  
Corrosion Performance ◽  
Gas Reservoir ◽  
Gas Field ◽  
Cost Factors

Cost factors must be considered in the development of Yan'an gas field. In order to evaluate the applicability of economical 80S steel in the sulfur gas reservoir environment of Yan'an gas field, the indoor corrosion test was conducted to evaluate the resistance of 80S steel to uniform corrosion and SCC resistance in CO2/H2S coexisting corrosion environment, and combined with relevant standards. The security was analyzed. The results show that the uniform corrosion rate of 80S steel is the largest at 50 °C, and it decreases first and then increases with the increase of temperature. When the loading stress is 496.8MPa (552MPa×90%),the test duration was 720h. One sample cracked and the other two parallel samples did not cracked Comprehensive anti-uniform corrosion performance and anti-SCC performance, it is believed that 80S steel has certain risks in the corrosive environment of Yan'an gas field. It needs to cooperate with other anti-corrosion measures and monitor the service of the well string at any time.

Adsorption and corrosion inhibition characteristics of two medicinal molecules

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Hydrochloric Acid ◽  
Corrosion Rate ◽  
Mild Steel ◽  
Corrosion Inhibition ◽  
Half Life ◽  
Thermodynamic Data ◽  
Inhibition Efficiency ◽  
Gravimetric Method ◽  
Corrosive Environment ◽  
Corrosion Inhibition Efficiency

The corrosion inhibition characteristics of two medicinal molecules phenylalanine and rutin on mild steel in 1.0M Hydrochloric acid were evaluated using gravimetric method. Corrosion inhibition efficiency of 83.78 and 90.40 % was obtained respectively after seven days. However, phenylalanine showed weak accumulative higher corrosion inhibition efficiency. The presence of both molecules in the corrosive environment reduced the corrosion rate constant and increased the material half-life. Thermodynamic data calculated suggests a spontaneous adsorption of the molecules on the mild steel’s surface.

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.

The Calculation of the Thickness for Uniform Corrosion and Localized Corrosion in Steel Corrosion

2011 ◽  
Vol 255-260 ◽  
pp. 514-518
Author(s):  
Zheng Yi Kong ◽  
Shan Hua Xu ◽  
Yu Sheng Chen
Keyword(s):  
Corrosion Rate ◽  
Constant Temperature ◽  
Safety Assessment ◽  
Steel Corrosion ◽  
Localized Corrosion ◽  
Power Relationship ◽  
Uniform Corrosion ◽  
Experiment Data ◽  
Temperature And Humidity ◽  
Corrosion Pits

Because of the complexity of corrosion, the law of uniform corrosion and localized corrosion is still not clear,so it is difficult to assess their impact on the structure safety. In order to differ them and find their own law, we obtain a lot of corrosion specimens by ways of constant temperature and humidity, and then detect the size of corrosion pits by roughness tester. After that, the method for calculating the thickness of uniform corrosion and localized corrosion is proposed. Then the method is used to analyze the experiment data. The result indicates the thickness of uniform corrosion and localized corrosion all increase with the rate of corrosion, and they all show a power relationship with corrosion rate, so it will provide a basis for distinguishing them in safety assessment.

scholarly journals ASESMEN KOROSI & ANALISIS RISIKO KUALITATIF PADA VERTIKAL BEJANA TEKAN

2021 ◽  
Vol 8 (2) ◽  
pp. 63-72
Author(s):  
Amam Fachrur Rozie ◽  
D.N Adnyana
Keyword(s):  
Risk Analysis ◽  
Corrosion Rate ◽  
Pressure Vessel ◽  
Atmospheric Corrosion ◽  
Uniform Corrosion ◽  
Vertical Pressure ◽  
Qualitative Risk Analysis ◽  
Non Destructive ◽  
Design Pressure

Keselamatan dan keamanan dalam penggunaan bejana tekan sangat penting dan hal utama dalam penggunaan bejana tekan, terlebih lagi jika bejana tekan tersebut sudah melewati umur desain nya. Penelitian ini bertujuan untuk menilai kelayakan kondisi terkini dari suatu bejana tekan vertikal (vertical pressure vessel) yang telah beroperasi sejak tahun 1970 tetapi berhenti beroperasi pada tahun 2011. Pendekatan penilaian pada bejana tekan vertikal ini berbasis pada metode penilaian korosi dan risiko secara kualitatif. Selain itu juga dipergunakan metode-metode lain dalam aspek penilaian nya seperti visual inspeksi, laju korosi (corrosion rate), Non-Destructive Examination (NDE), software calculation dan analisa risiko kualitatif (qualitative risk analysis). Dari hasil observasi dan inspeksi di dapat tekanan desain (design pressure) adalah 7 kg/cm2, Temperatur desain (design temperature) adalah 61°C dengan material konstruksi adalah SA-283 Gr. C dan standard & code yang dipergunakan adalah ASME Sect. VIII Div. 1 dan API 510 serta beberapa standard & code lainnya. Dari hasil kajian dan kalkulasi di lapangan, maka didapat faktor penyebab kerusakan yang kemungkinan terjadi adalah atmospheric corrosion & uniform corrosion dengan nilai laju korosi adalah sebesar 0,127mm/yr dan tingkat risiko dari bejana tekan vertikal ini masuk dalam kategori 2D yang artinya adalah medium-high dengan maksimal umur pakai sampai usia 27 tahun untuk top head dan 24 tahun dan bottom head serta 23 tahun untuk shell. Sehingga dapat disimpulkan bahwa bejana tekan ini masih aman dan layak dipergunakan dengan batasan-batasan di atas.

Bayesian Estimation of Cumulative Damage From Seismic Response Records of Buildings

2001 ◽  
Author(s):  
Ernesto Heredia-Zavoni ◽  
Antonio Zeballos ◽  
Roberto Montes-Iturrizaga ◽  
Luis Esteva
Keyword(s):  
Mechanical Properties ◽  
Probability Distributions ◽  
Damage Function ◽  
Cumulative Damage ◽  
Degree Of Freedom ◽  
Inelastic Behavior ◽  
Concrete Frames ◽  
Inelastic Response ◽  
Bayesian Formulation ◽  
Secant Stiffness

Abstract This paper discusses the estimation of probability distributions of damage using response records from instrumented buildings subjected to seismic excitations. The objective of the paper is to show how the information on the evolution of the mechanical properties of a system can be used to assess the state of cumulative damage. This implies expressing damage on the structural members in terms of its influence on the residual mechanical properties of the system. The information on the inelastic behavior from response records is used in a bayesian formulation along with a damage function to update prior probability distributions of damage. The damage function models the hysteretic cycles of inelastic response in terms of an initial damage and of the displacement amplitudes of the response cycles. It describes the evolution of the secant stiffness through the cycles of inelastic response as a function of cumulative damage and displacement amplitudes. The updating of probability distributions of damage for single degree of freedom systems is presented first. Extensions to the case of non-linear multi-degree of freedom systems are discussed next. Examples of reinforced concrete frames are given for illustrative purposes.

scholarly journals Corrosive Environment Assessment and Corrosion-Induced Rockbolt Failure Analysis in a Costal Underground Mine

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Qifeng Guo ◽  
Jiliang Pan ◽  
Min Wang ◽  
Meifeng Cai ◽  
Xun Xi
Keyword(s):  
Chemical Composition ◽  
Corrosion Rate ◽  
Time Dependent ◽  
Gold Mine ◽  
System Failure ◽  
Corrosive Environment ◽  
Support Design ◽  
Ph Values ◽  
Environment Assessment

As an effective ground-reinforcing system, rockbolts have been widely used in underground excavations. Corrosion of rockbolts has been one of the most reasons for rockbolts system failure. In this paper, the chemical composition and pH values of the groundwater in Sanshandao Gold mine are first tested. Corrosion of the slotted rockbolts used in roadways of the mine is analysed. The corrosion rate of rockbolts is evaluated based on experimental results from similar corrosive conditions. A time-dependent analytical model on anchoring force degradation caused by corrosion of the rockbolt is developed. Furthermore, the effects of corrosion rate and geometric parameters of the slotted rockbolts on anchoring force degradation are discussed. Suggestions on rockbolts support design in corrosive conditions are given. It has been found that, with the corrosion time increasing, the anchoring force between the rock and the rockbolt gradually decreases. The larger the corrosion rate is, the faster the anchoring force decreases. For long-term service roadways under corrosive conditions, a slotted rockbolt with a smaller radius and thicker wall can enhance the anchoring force.

Fatigue Damage Estimation of Welded Joints Considering Mechanochemical Interaction

2017 ◽  
Author(s):  
Gang Liu ◽  
Yi Huang ◽  
Qi Zhang ◽  
Zhiyuan Li ◽  
Jingjie Chen ◽  
...  
Keyword(s):  
Corrosion Rate ◽  
Fatigue Damage ◽  
Coupling Effect ◽  
Hot Spot ◽  
Plate Thickness ◽  
High Stress ◽  
Uniform Corrosion ◽  
Hot Spot Stress ◽  
Butt Weld ◽  
Applied Loading

The high stress region around weld joints accelerates corrosion and may induce non-uniform corrosion. In this study, the effect of loading on corrosion behavior of the steel in NaCl solution was investigated. The relationship between the corrosion rate and applied loading was deduced based on the electrochemical theory. Electrochemical experiments were carried out to investigate the interaction between loading and corrosion rate on Q235 steel. A butt weld joint of ship deck structure was selected as a case study. Time-dependent stress concentration factor of welded joint as a function of the corrosion deterioration was analyzed, and the iterative process of stress and corrosion degeneration of plate thickness was used to simulate the coupling effect based on results of the experiment. The hot spot stress approach was adopted to calculate the fatigue damage.

PENGARUH BASIC SEDIMENT AND WATER TERHADAP LAJU KOROSI PIPA X52 DAN A53 PADA MEDIA OIL SLUDGE.

ROTOR ◽  
2017 ◽  
Vol 10 (1) ◽  
pp. 13
Author(s):  
Naufan Arviansyah ◽  
Sumarji Sumarji ◽  
Digdo Listyadi Setyawan
Keyword(s):  
Weight Loss ◽  
Carbon Steel ◽  
Corrosion Rate ◽  
Low Carbon Steel ◽  
Measuring Method ◽  
Oil Sludge ◽  
Uniform Corrosion ◽  
Low Carbon ◽  
Weight Loss Method ◽  
Loss Method

This research have a purpuse to know corrosion rate in pipe X52 and A53 at oil sludge media caused BS and W. Corrosion is a damage of metal that occurs because reaction between metal with environtment and produce unwanted of corrosion product. Pipe X52 and A53 is a type of low carbon steel that use for fluid transportation system in industry. Oil sludge is a sediment of crude oil from main gathering storage and containing variouses elements. Oil sludge have a one of element is Basic Sediment and Water that is can make corrosion happen to distribution pipes. Measuring Method used in this research is weight loss method. The result of corrosion rate in Oil Sludge media containing 30,17% BS and W for pipe A53 is 1,64 x 10-2 mmpy and the result for pipa X52 is 2,47 x 10-2 mmpy. The result of corrosion rate in Oil Sludge media containing 60,67% BS and W for pipe A53 is 2,12 x 10-2 mmpy and for pipe X52 the result is 3,13 x 10-2 mmpy. The result of this research showed pipe A53 have more resistance than pipe X52. The corrosion is classified as uniform corrosion. Keywords : A53, Weight Loss, Oil Sludge, X52.

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