Stress Analysis of Unnotched C-Rings Used for Stress Cracking Studies

1968 ◽  
Vol 90 (1) ◽  
pp. 147-152 ◽  
Author(s):  
S. O. Fernandez ◽  
G. F. Tisinai
Keyword(s):  
Hydrogen Embrittlement ◽  
Stress Analysis ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Stress Cracking ◽  
Ring Sample ◽  
Sulfide Stress ◽  
Sulfide Stress Cracking ◽  
Elastic Strains

A technique for measuring elastic strains and the location between the plastically and elastically deformed portions of an unnotched C-ring sample is presented. Such C-rings when used to study sulfide stress cracking may incur cracks caused by both hydrogen embrittlement and stress corrosion cracking, whereas the presence of notches in the C-rings conceivably may force failure by only hydrogen embrittlement. Current studies by the authors on sulfide stress cracking include the use of both notched and unnotched C-rings.

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.

Stress Corrosion Cracking of Low Strength, Low Alloy Nickel Steels in Sulfide Environments

CORROSION ◽  
1978 ◽  
Vol 34 (3) ◽  
pp. 88-96 ◽  
Author(s):  
A. K. DUNLOP
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Hydrate Formation ◽  
Corrosion Cracking ◽  
Beam Specimen ◽  
Stress Cracking ◽  
Partial Pressures ◽  
Sulfide Corrosion ◽  
Sulfide Stress ◽  
Low Strength

Abstract Factors governing stress corrosion cracking (SCC) of low strength, low alloy nickel steels (e.g., ASTM A203 Grade E) in sulfide environments were investigated using a three point loaded bent beam specimen. Cracking occurred in both weld and base metal at low H2S partial pressures (to 0.001 atmosphere) and stress levels, but could be inhibited by a neutralizing amine (morpholine) and methanol addition as used for control of ice and hydrate formation in cryogenic gas plants. Cathodic polarization experiments showed cracking was retarded under these conditions. This indicates the cracking phenomenon involved is not that of hydrogen embrittlement (i.e., sulfide stress cracking) as has been heretofore assumed, but involves localized anodic attack as does the cracking of other low strength alloys in environments such as nitrate, caustic, CO/CO2, etc. Sulfide corrosion stress cracking (SCSC) is suggested as a term for this type of localized anodic cracking attack in sulfide environments.

Sulfide stress cracking inhibition of a supermartensitic stainless steel by using an imidazol obtained from palm oil

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jose-Gonzalo Gonzalez-Rodriguez ◽  
Andres Carmona Hernandez ◽  
E. Vázquez-Vélez ◽  
A. Contreras-Cuevas ◽  
Jorge Uruchurtu Chavarin
Keyword(s):  
Stainless Steel ◽  
Stress Corrosion ◽  
Palm Oil ◽  
Stress Corrosion Cracking ◽  
Content Type ◽  
Supermartensitic Stainless Steel ◽  
Stress Cracking ◽  
Sulfide Stress ◽  
Sulfide Stress Cracking ◽  
Sulfide Stress Corrosion Cracking

Purpose This paper aims to use an imidazole-based n-ionic Gemini surfactant derived from palm oil to inhibit the sulfide stress corrosion cracking of a supermartensitic stainless steel. Design/methodology/approach The slow strain rate testing technique, hydrogen permeation tests and potentiodynamic polarization curves have been used. Findings Addition of the inhibitor below the critical micelle concentration (CMC) decreased the corrosion current density (icorr), but not enough to avoid embrittlement due to the entry of hydrogen into the steel. Instead, the addition of the inhibitor close to the CMC decreased the icorr, suppressed the entry of hydrogen and inhibited the sulfide stress cracking of steel. Finally, the addition of inhibitor above the CMC led to a slight increase of icorr and promoted localized corrosion, however, the sulfide stress cracking of steel was inhibited. Originality/value A green sulfide stress corrosion cracking inhibitor of a supermartensitic stainless steel has been obtained.

scholarly journals Stress Corrosion Cracking of Additively Manufactured Alloy 625

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6115
Author(s):  
Marina Cabrini ◽  
Sergio Lorenzi ◽  
Cristian Testa ◽  
Francesco Carugo ◽  
Tommaso Pastore ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Hydrogen Embrittlement ◽  
Strain Rate ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
High Strain ◽  
Corrosion Cracking ◽  
Slow Strain Rate ◽  
Laser Source ◽  
Alloy 625

Laser bed powder fusion (LPBF) is an additive manufacturing technology for the fabrication of semi-finished components directly from computer-aided design modelling, through melting and consolidation, layer upon layer, of a metallic powder, with a laser source. This manufacturing technique is particularly indicated for poor machinable alloys, such as Alloy 625. However, the unique microstructure generated could modify the resistance of the alloy to environment assisted cracking. The aim of this work was to analyze the stress corrosion cracking (SCC) and hydrogen embrittlement resistance behavior of Alloy 625 obtained by LPBF, both in as-built condition and after a standard heat treatment (grade 1). U-bend testing performed in boiling magnesium chloride at 155 and 170 °C confirmed the immunity of the alloy to SCC. However, slow strain rate tests in simulated ocean water on cathodically polarized specimens highlighted the possibility of the occurrence of hydrogen embrittlement in a specific range of strain rate and cathodic polarization. The very fine grain size and dislocation density of the thermally untreated specimens appeared to increase the hydrogen diffusion and embrittlement effect on pre-charged specimens that were deformed at the high strain rate. Conversely, heat treatment appeared to mitigate hydrogen embrittlement at high strain rates, however at the slow strain rate all the specimens showed a similar behavior.

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