Hydrogen Embrittlement of Cathodically Protected Subsea Bolting Alloys

Normal operations of cathodic protection systems caused hydrogen embrittlement failures of subsea bolts of Monel® K-500 on offshore platforms. Subsequent testing showed that the embrittlement could be predicted from cathodically protected slow strain rate tensile tests. Additional slow strain rate tests have shown that cathodic protection caused embrittlement of Ferralium® 255, Inconel® X-750, Inconel® 718, high strength steel, and 13 percent Chromium alloys but not of beryllium copper, A-286, Beta-C® titanium, and steel at a yield strength of 115 ksi.