scholarly journals Developing Field Test Procedures for Chloride Stress Corrosion Cracking in the Arabian Gulf

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Hanan Farhat
Keyword(s):  
Stress Corrosion ◽  
Field Test ◽  
Stress Corrosion Cracking ◽  
Environmental Conditions ◽  
Oil And Gas ◽  
Arabian Gulf ◽  
Gas Production ◽  
Corrosion Cracking ◽  
Test Procedures ◽  
Accuracy And Repeatability

Oil and gas production and petrochemical plants in the Arabian Gulf are exposed to severe environmental conditions of high temperature and humidity. This makes these plants susceptible to chloride-induced stress corrosion cracking (CSCC). The laboratory testing fails to provide the exact field environmental conditions. A cost efficient field test setup for CSCC was designed and developed for the Arabian Gulf. The setup included designing self-sustained loading devices, samples, and sample racks. The samples were exposed to a stress equivalent to 80% and 100% of their yield strength. This paper describes the developed test procedures to establish testing with high level of accuracy and repeatability. It also discusses the design aspects and the challenges that were met.

The role of crack branching in stress corrosion cracking of aluminium alloys

2015 ◽  
Vol 33 (6) ◽  
pp. 443-454 ◽  
Author(s):  
Timothy L. Burnett ◽  
N.J. Henry Holroyd ◽  
Geoffrey M. Scamans ◽  
Xiaorong Zhou ◽  
George E. Thompson ◽  
...  
Keyword(s):  
Stress Intensity ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Aluminium Alloys ◽  
Compact Tension ◽  
Corrosion Cracking ◽  
Three Dimensions ◽  
Crack Branching ◽  
Test Procedures ◽  
The Many

AbstractStress corrosion cracks of all types are characterised by extensive crack branching, and this is frequently used as the key failure analysis characteristic to identify this type of cracking. For aluminium alloys, stress corrosion cracking (SCC) is almost exclusively an intergranular failure mechanism. For plate and extruded components, this had led to the development of test procedures using double cantilever beam and compact tension precracked specimens that rely on the pancake grain shape to constrain cracking, so that fracture mechanics can be applied to the analysis of stress intensity and crack velocity and the evolution of a characteristic performance curve. We have used X-ray computed tomography to examine in detail SCC in aluminium alloys in three dimensions for the first time. We have found that crack branching limits the stress intensity at the crack tip as the applied stress is shared amongst a number of cracks that are held together by uncracked ligaments. We propose that the plateau region observed in the v-K curve is an artefact due to crack branching, and at the crack tips of the many crack branches, cracking essentially occurs at constant K almost irrespective of the crack length. We have amplified the crack branching effect by examining a sample where the long axis of the pancake grains was inclined to the applied stressing direction. Our results have profound implications for the future use of precracked specimens for SCC susceptibility testing and the interpretation of results from these tests.

Moly Disulfide in Bolting Applications

2016 ◽  
Author(s):  
Donald Oldiges ◽  
Scott Hamilton
Keyword(s):  
Stress Corrosion ◽  
Molybdenum Disulfide ◽  
Stress Corrosion Cracking ◽  
Environmental Conditions ◽  
Corrosion Potential ◽  
Corrosion Cracking ◽  
The Past ◽  
Pros And Cons

Molybdenum disulfide (MoS2) is a popular lubricant, however a study completed in the early 1990’s stated that this type of lubricant can lead to stress corrosion cracking (SSCC) of the bolting materials. However, over the past 20 years, many bolting applications using molybdenum disulfide based compounds have been found to provide better galling resistance to the bolt assembly than many other components. It has also been shown to have a few other less desirable traits such as potential for corrosion in specific environments. Therefore, for successful bolting applications one must consider all the pros and cons of the anti-seize compound they select. One of the negative properties of molybdenum compounds is their link to SSCC on some alloys in specific environmental conditions. This paper focuses on corrosion potential.

Evaluation of Stress Corrosion Cracking, Sulfide Stress Cracking, Galvanic-Induced Hydrogen Stress Cracking, and Hydrogen Embrittlement Resistance of Aged UNS N06625 Forged Bars

CORROSION ◽  
10.5006/3590 ◽  
2020 ◽  
Vol 76 (12) ◽  
pp. 1207-1219
Author(s):  
A. Febbrari ◽  
R. Montani ◽  
C. Veronesi ◽  
M. Cavagnola ◽  
E. Brognoli ◽  
...  
Keyword(s):  
Hydrogen Embrittlement ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Oil And Gas ◽  
Corrosion Cracking ◽  
Aged Alloy ◽  
Second Phase ◽  
Stress Cracking ◽  
Sulfide Stress ◽  
Sulfide Stress Cracking

UNS N06625 is a nickel-based superalloy used for oil and gas applications and commonly produced according to NACE MR0175 in the annealed/solution annealed condition. The annealing/solution annealing treatment makes the material corrosion resistant in the most challenging environments, in the presence of sulfides and chlorides at high pressure and temperature. However, thanks to its chemical composition, UNS N06625 can also be considered as an age-hardenable material whose mechanical strength can be improved by promoting the metastable second phase γ′′ precipitation into the γ matrix. However, the corrosion behavior of the aged alloy has never been investigated in NACE environments. This paper aims to understand the suitability of the age-hardened condition of UNS N06625 for oil and gas applications through the evaluation of the material corrosion performance in NACE level VII environments by using NACE TM0177 tests. Three heats of UNS N06625 have been produced and forged in different bar diameters: 152 mm (6 in), 203.2 mm (8 in), and 254 mm (10 in). Afterward, the bars have been annealed and age-hardened according to optimized time-temperature parameters and finally tested to assess their mechanical properties and resistance to stress corrosion cracking, sulfide stress cracking, galvanic-induced hydrogen stress cracking, and hydrogen embrittlement.

Study of the Susceptibility of API 5L X80 Girth Welds to Sulfide Stress Corrosion Cracking and Hydrogen Embrittlement

2010 ◽  
Author(s):  
Adriana Forero Ballesteros ◽  
Jose´ A. da Cunha Ponciano ◽  
Ivani de S. Bott
Keyword(s):  
Hydrogen Embrittlement ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Oil And Gas ◽  
Hydrogen Permeation ◽  
Sodium Thiosulfate ◽  
Corrosion Cracking ◽  
Transmission Pipeline ◽  
Girth Welds ◽  
Almost All

The growing demand for natural gas and oil, as energy sources, has driven industry’s need for ever-increasing strength levels in oil and gas transmission pipeline materials in order to achieve safe and economic transportation. The current world trend points to the use of pipes with larger diameters and thinner wall thicknesses, operating under high pressure. In addition, pipeline steels for sour service must exhibit good Hydrogen Induced Cracking (HIC) and Sulphide Stress Corrosion Cracking (SSCC) resistance. This study evaluates the susceptibility of API 5L-X80 girth welds to SSCC and Hydrogen Embrittlement (HE). Slow strain rate tensile (SSRT) tests and Hydrogen Permeation tests were performed at room temperature, in different acidic environment containing sodium thiosulfate solutions. Most of the SSRT tests undertaken in solution, showed a loss of ductility and a decrease in the reduction of area, as compared with tests conducted in air. The susceptibility to HE and potentially SSCC was evidenced by a reduction in ductility in the SSRT tests and an increase in the hydrogen permeation current values, for almost all welded joints. This was observed with greater intensity for the more acidic test solutions (pH = 3.4), while for the less acidic test solutions (pH = 4.4) little loss of ductility was observed and the hydrogen permeation current remained at values close to zero, indicating little or no permeation of hydrogen through the metal for the testing times applied. The behaviour exhibited by the samples tested in the more acidic solutions was attributed to the dissolution of material from the sample together with hydrogen embrittlement. These results confirmed that the use of sodium thiosulfate solutions to generate H2S, permits the study of phenomena related to SCC in environments containing sulphides.

Fatigue and SCC Lifetime Enhancement of Steels by Means of Laser Peening

2011 ◽  
Author(s):  
Lloyd A. Hackel ◽  
C. Brent Dane ◽  
Jon Rankin ◽  
Fritz Harris ◽  
Chanh Truong ◽  
...  
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Oil And Gas ◽  
Fatigue Cracking ◽  
Deep Levels ◽  
Corrosion Cracking ◽  
High Rate ◽  
Oil Refining ◽  
Laser Peening ◽  
Resistance To Stress

Laser peening is a technology employed to induce deep levels of plasticity in materials resulting in compressive residual stress to depths of 5mm (0.2 inches) or deeper enabling increased fatigue strength and lifetimes and greatly enhanced resistance to stress corrosion cracking. An advanced in Nd:glass laser technology has enabled high rate, cost effective industrial deployment of the technology that is now being widely used in aerospace and electric power generation applications. Examples of deep levels of compressive stress and resulting improvements in fatigue life and resistance to stress corrosion cracking will be shown. An advanced beam delivery technology incorporating a robotic arm coupled with a video detection/beam alignment system is enabling rapid setup and application in field applications. The technology has been approved and deployed to prevent early fatigue cracking of key structural components on the F-22 fighter jet. It is also being applied to oil and natural gas applications and has the potential to serve a broad base of field applications including oil and gas lines, on-board ship SCC, nuclear power plant SCC, and fatigue and corrosion applications in upstream exploration and downstream oil refining.

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