Confirmation of Hydrogen Embrittlement Mechanism for Stress Corrosion Cracking of Gas Main Lines

2021 ◽  
Vol 410 ◽  
pp. 572-577
Author(s):  
Natalya I. Volgina ◽  
Aleksander V. Shulgin ◽  
Svetlana S. Khlamkova
Keyword(s):  
Hydrogen Embrittlement ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Growth Stage ◽  
Subcritical Crack Growth ◽  
Corrosion Cracking ◽  
Pipe Surface ◽  
Subcritical Growth ◽  
Three Stages ◽  
Corrosion Defects

The nature and mechanism of stress corrosion cracking have been studied and modeled in laboratory conditions. It was established that the destruction process develops in three stages: the formation of corrosion defects on the pipe surface, birth and subcritical growth of stress-corrosion cracks, and break. Release bands observed in focal fracture at subcritical crack growth stage indicate that fluctuating stresses are involved in the destruction development. Transcrystalline nature of the fracture at subcritical growth stage implies that SCC in pipelines develops in consonance with the hydrogen embrittlement mechanism.

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.

scholarly journals Hydrogen effects in non-ferrous alloys: discussion

2017 ◽  
Vol 375 (2098) ◽  
pp. 20170030 ◽  
Author(s):  
Mitesh Patel ◽  
Miles A. Stopher
Keyword(s):  
Hydrogen Embrittlement ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Discussion Session ◽  
Ferrous Alloys ◽  
Delayed Hydride Cracking ◽  
Hydride Cracking

This is a transcript of the discussion session on the effects of hydrogen in the non-ferrous alloys of zirconium and titanium, which are anisotropic hydride-forming metals. The four talks focus on the hydrogen embrittlement mechanisms that affect zirconium and titanium components, which are respectively used in the nuclear and aerospace industries. Two specific mechanisms are delayed hydride cracking and stress corrosion cracking. This article is part of the themed issue ‘The challenges of hydrogen and metals’.

Influence of Mooring Chain Steel Strength on Stress Corrosion Cracking

2013 ◽  
Vol 404 ◽  
pp. 32-39 ◽  
Author(s):  
Xiao Ying Cheng ◽  
Hong Yuan Chen ◽  
Wen Qing Liu ◽  
Zhi Juan Zhang
Keyword(s):  
Hydrogen Embrittlement ◽  
Stress Corrosion ◽  
Failure Mechanism ◽  
Anodic Dissolution ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Lower Strength ◽  
Synthetic Seawater ◽  
Steel Strength ◽  
Mooring Chain

Two strength mooring chain steels were used to investigate the stress corrosion cracking (SCC) in synthetic seawater. The resistance of both strength steels to SCC was similar in neutral synthetic seawater. But the failure mechanism was different. For lower strength steel, it is mainly induced by anodic dissolution, while for higher strength steel, by hydrogen embrittlement. The reason was elucidated from their microstructures and corrosion characteristics.

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