Safe operation of gas pipelines based on the control of stress corrosion cracking

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ilya Ryakhovskikh ◽  
Roman Kashkovskiy ◽  
Aleksandr Kaverin ◽  
Vladimir Stolov ◽  
Sergey Zhedulov
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Large Diameter ◽  
Corrosion Cracking ◽  
Transport Systems ◽  
Residual Service Life ◽  
Gas Pipelines ◽  
Safe Operation ◽  
Content Type ◽  
Analytical Approaches

PurposeThe paper is devoted to the phenomenon of stress corrosion cracking (SCC), which is an urgent problem for major operator companies that use large-diameter gas transport systems built in the second half of the last century. The aim of the study is to predict the operability of gas pipelines with SCC and ensure their safe operation.Design/methodology/approachThe methodology of the article mainly consisted of strength calculations, mathematical and analytical approaches.FindingsThe paper describes practical methods of assessing the residual service life and operability of pipes with SCC defects as part of gas pipelines, the developed approaches to assessing the point of failure of pipes, provides recommendations for developing requirements to ILI smart tools in order to detect cracks and the methods of pipe repair depending on the SCC defect parameters.Originality/valueThe originality of the study consists in the analytical description of the point of destruction of gas pipelines with SCC, assessment of their performance, as well as the definition of modern requirements for the accuracy of in-line inspection to ensure the detection of potentially dangerous SCC defects.

Validation of EMAT ILI for Management of Stress Corrosion Cracking in Natural Gas Pipelines

2014 ◽  
Author(s):  
Toby Fore ◽  
Stefan Klein ◽  
Chris Yoxall ◽  
Stan Cone
Keyword(s):  
High Resolution ◽  
Natural Gas ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Probability Of Detection ◽  
Gas Pipelines ◽  
Line Pipe ◽  
Natural Gas Pipelines ◽  
Electro Magnetic

Managing the threat of Stress Corrosion Cracking (SCC) in natural gas pipelines continues to be an area of focus for many operating companies with potentially susceptible pipelines. This paper describes the validation process of the high-resolution Electro-Magnetic Acoustical Transducer (EMAT) In-Line Inspection (ILI) technology for detection of SCC prior to scheduled pressure tests of inspected line pipe valve sections. The validation of the EMAT technology covered the application of high-resolution EMAT ILI and determining the Probability Of Detection (POD) and Identification (POI). The ILI verification process is in accordance to a API 1163 Level 3 validation. It is described in detail for 30″ and 36″ pipeline segments. Both segments are known to have an SCC history. Correlation of EMAT ILI calls to manual non-destructive measurements and destructively tested SCC samples lead to a comprehensive understanding of the capabilities of the EMAT technology and the associated process for managing the SCC threat. Based on the data gathered, the dimensional tool tolerances in terms of length and depth are derived.

Weld Residual Stresses and Primary Water Stress Corrosion Cracking in Bimetal Nuclear Pipe Welds

2007 ◽  
Author(s):  
Frederick W. Brust ◽  
Paul M. Scott
Keyword(s):  
Water Stress ◽  
Residual Stresses ◽  
Weld Metal ◽  
Stress Corrosion ◽  
Crack Growth ◽  
Stress Corrosion Cracking ◽  
Pressure Vessel ◽  
Large Diameter ◽  
Corrosion Cracking ◽  
Primary Water

There have been incidents recently where cracking has been observed in the bi-metallic welds that join the hot leg to the reactor pressure vessel nozzle. The hot leg pipes are typically large diameter, thick wall pipes. Typically, an inconel weld metal is used to join the ferritic pressure vessel steel to the stainless steel pipe. The cracking, mainly confined to the inconel weld metal, is caused by corrosion mechanisms. Tensile weld residual stresses, in addition to service loads, contribute to PWSCC (Primary Water Stress Corrosion Cracking) crack growth. In addition to the large diameter hot leg pipe, cracking in other piping components of different sizes has been observed. For instance, surge lines and spray line cracking has been observed that has been attributed to this degradation mechanism. Here we present some models which are used to predict the PWSCC behavior in nuclear piping. This includes weld model solutions of bimetal pipe welds along with an example calculation of PWSCC crack growth in a hot leg. Risk based considerations are also discussed.

scholarly journals Correlation Between the Resistance to Stress Corrosion Cracking of Steel Tubes of Gas Pipelines with Their Layerwise Texture Inhomogeneity

2018 ◽  
Vol 4 (1) ◽  
pp. 179
Author(s):  
Y A Perlovich ◽  
I V Ryakhovskikh ◽  
M G Isaenkova ◽  
O A Krymskaya ◽  
N S Morozov ◽  
...  
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Gas Pipelines ◽  
Steel Tubes ◽  
Resistance To Stress

.

Materials for Generator Retaining Rings

1981 ◽  
Vol 103 (4) ◽  
pp. 267-275 ◽  
Author(s):  
R. Viswanathan
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
State Of The Art ◽  
Corrosion Cracking ◽  
Safe Operation

Retaining rings are among the highest stressed components of electricial generators, whose integrity is critical to the reliable and safe operation of the generators. The steel currently used for this application is susceptible to stress corrosion cracking and is also limited by yield strength to about 1200 MPa. The use of alternate materials with improved mechanical properties can enhance the reliability, efficiency, size capability and availability of generators. This paper is a state-of-the-art review of the materials technology pertaining to retaining rings.

scholarly journals Hydrogen-Induced Stress Corrosion Cracking of Pipe Lines of Russia

1996 ◽  
Author(s):  
Tatyana K. Sergeyeva ◽  
Igor A. Tychkin ◽  
Gennady G. Vasiliev
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Large Diameter ◽  
Corrosion Cracking ◽  
Slow Strain Rate Test ◽  
Corrosion Mechanism ◽  
Hydrogen Distribution ◽  
Induced Stress ◽  
Rate Test ◽  
Large Diameter Pipes

The results of expert studies of large diameter pipes damaged due to external stress corrosion cracking are presented in the report. These data obtained in the 1993–1995 are typical for various regions of Russia. The results of laboratory studies of the stress-corrosion mechanism for pipe steels in suspensions of soils from the places where the operating failure had occurred are given in the report also. The mechanism of hydrogen-induced stress-corrosion cracking (HISCC) realizing through local hydrogenation of steel during plastic deformation has been determined by means of the technique of slow strain rate test (SSRT) of samples in the soil under cathodic, anodic and free corrosion potentials in combination with hydrogenation and hydrogen distribution analyses along length of a sample. No hydrogenation of volumes of pipes non-subjected to cracking was observed but hydrogenation took place in the zones subjected to stress corrosion.

Effect of non-conventional heat treatment of API X60 pipeline steel on corrosion resistance and stress corrosion cracking susceptibility

2019 ◽  
Vol 66 (3) ◽  
pp. 274-285 ◽  
Author(s):  
Luis Ricardo Jacobo ◽  
Rafael Garcia ◽  
Victor Hugo Lopez ◽  
Antonio Contreras
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Strain Rate ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Activation Process ◽  
Content Type ◽  
Heat Treated ◽  
Conventional Heat Treatment

Purpose The purpose of this paper is to study the effect of heat treatment (HT) applied to an API X60 steel in corrosion resistance and stress corrosion cracking (SCC) susceptibility through slow strain rate tests (SSRT) in NS4 solution and congenital water (CW) to assess external and internal SCC, respectively. Design/methodology/approach API X60 steel was heat treated at a temperature of 1,200°C for 30 min followed by water quenching. Specimens from this steel were machined according to NACE TM 198. SSRT were performed in a constant extension rate tests (CERT) machine at room temperature at a strain rate of 1 × 10–6 s–1. For this purpose, a glass cell was used. Corrosion behavior was evaluated through polarization curves (PCs). Findings The SCC index obtained from SSRT indicates that the steel heat treated could be susceptible to SCC in CW and NS4 solution; the mechanism of SCC was hydrogen embrittlement. Thus, CW may promote the SCC phenomenon in pipelines. HT improves the steel corrosion resistance. Higher corrosion rate (CR) was observed when the steel is exposed to CW. The corrosion process in X60 steel shows that the oxidation reaction in the anodic branch corresponds to an activation process, and the cathode branches reveal a diffusion process. Originality/value The purpose of the heat treatment applied to X60 steel was to generate a microstructure of acicular ferrite to improve the corrosion resistance and SCC behavior.

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