Hydrogen embrittlement of X2CrNiMoCuN25-6-3 super duplex stainless steel welded joints under cathodic protection

The effect of cathodic polarization conditions on hydrogen degradation of X2CrNiMoCuN25-6-3 super duplex stainless steel welded joints, obtained using flux cored arc and submerged arc welding methods, was evaluated. Slow strain rate tensile tests of base material and welded specimens, ferrite content measurements, scanning electron microscopy observations, and statistical analysis were performed. It was found that hydrogenation of super duplex steel welded joints under the conditions of cathodic protection in artificial seawater environment leads to hydrogen embrittlement and that the weld area shows the highest degree of degradation. Welded joints made with higher heat input and under higher current density tend to cause an increase in the degradation of mechanical properties. A series of models to analyze the relationship between conditions and properties of material under extreme environmental conditions were successfully elaborated and evaluated. (C) 2019 Elsevier Ltd. All rights reserved.