Evaluation of the resistance to hydrogen embrittlement by slow bending test

The paper reports on a slow strain rate technique employed for studying the resistance to hydrogen embrittlement (HE) of steels under cathodic protection, based on bending test. The technique has been applied to linepipe steels, ranging from 420 to 770 MPa (60-110 ksi) TYS. A procedure based on slow bending tests has been set up and the plastic strain field of the specimen during bending has been calculated through a bi-dimension finite element analysis. The results of bending tests performed in 3.5% NaCl under cathodic protection at potentials in the range from -900 to -1050 mV vs SCE are discussed and compared with data collected by axial SSR tests