Sammendrag
The risk of stress corrosion cracking (SCC) under exposure to H2S, also denoted sulphide stress cracking (SSC), has been discussed and investigated by research institutions and end users of susceptible material qualities for decades. Many mechanisms have been identified and the influence of the most critical environmental parameters has been revealed experimentally. However, an experimental-numerical modelling approach to better understanding this phenomenon is not reported extensively in the literature. Hence, the intention with this project has been to link the results from well defined experimental testing with suitable numerical models developed by SINTEF and research colleagues at LMT in Paris to get one step closer to the possibility of predicting this phenomenon by modelling instead of testing in the laboratory. In addition to this, in-situ monitoring methods like potential drop (PD), acoustic emission (AE) and electro-chemical potential measurements have been tested out for different environments. The selected material quality was a 13% Cr super martensitic stainless steel from a recovered pipeline in the North Sea. The same material has been used in the HISC project (JIP). In this way it has been possible to compare the results from the H2S testing in this project with the results from the HISC-project with regard to hydrogen absorption. It has also been carried out element/phase analysis of the material and a state of the art literature study to identify the relationship between critical parameters, their synergy and status with regard to computer modelling of this phenomenon. The experimental testing has been performed in SINTEF’s slow strain rate testing (SSRT) rig, but was restricted significantly due to severe technical problems with the rig that lasted for months. However, some interesting results were obtained and areas to be studied in the future are identified. The project was funded entirety by SINTEF Materials and Chemistry.
Vis fullstendig beskrivelse
