Fatigue corrosion behavior of friction-welded stainless and carbon steel dissimilar joint

This study investigates the fatigue corrosion behavior of direct drive friction welded ASTM A105 and AISI 304L steels joints. Axial fatigue tests were carried out at a stress ratio of R = 0.1 in air and different corrosive environments using a 3D printed environmental test cell. The samples were tested in 3.5%(wt) NaCl aqueous solution at free corrosion potential (E-corr) and other two polarization conditions (-0.85 and -1.30 V vs. Ag/AgCl) with the objective to highlight the influence of the cathodic protection and the influence of evolved hydrogen on the fatigue behavior. Fracture analyses were conducted through optical and electron microscopy to identify the possible causes of failure nucleation and the different damage mechanisms dictated by the aggressive environment. Principal results quantify the detrimental effect of the corrosive environment and the positive role played by the cathodic protection. Moreover, a clear differentiation in the failure site and mechanism was observed for the different corrosion fatigue conditions.