Hydrogen embrittlement of cathodically protected high strength steel in sea water and seabed sediment

Hydrogen embrittlement tests were carried out using double cantilever beam and slow strain rate tensile specimens to measure the susceptibility of a 900 MPa yield strength steel in different marine environments, ranging from sterile sea water and filtered natural sea water to open sea water and seabed sediment. The cathodic protection potential and the presence of biologically generated sulphides in seabed sediment were shown to be important factors that controlled the extent of hydrogen uptake and embrittlement. Threshold stress intensities K-th were measured for each condition and the optimum catholic protection potential to control corrosion with the minimum risk of embrittlement was established.