Comparative assessment of mechanical properties of HPS between electrochemical corrosion and spray corrosion

An experimental study was conducted to compare the deterioration of mechanical properties of HPS specimens subjected to electrochemical corrosion and neutral salt spray accelerated corrosion. Twenty seven 460D steel specimens were designed and subjected to these two kinds of corrosion. The geometric features of the specimens were evaluated by using 3D scanning technology. Mechanical properties and corrosion damage were discussed after tensile tests. FEM was developed to investigate the effects of different corroded cross sections and their spacing on the degradation of mechanical properties. Experimental results show that specimens subjected to the electrochemical accelerated corrosion have more obvious non-uniformity. Shape of big pits in terms of the electrochemical accelerated corrosion can be regarded as a flat semi-ellipsoid, and part of a full semi-ellipsoid for salt spray accelerated corrosion, and cone for the small pits. Corrosion method has an effect on the ductility, strength, and failure behaviors. Compared with thickness loss, width loss has a greater impact on structural strength and stiffness.