STUDY ON THE ACCELERATED CORROSION BEHAVIOR OF A GALVANIZED X80 PIPELINE STEEL WELDED JOINT DURING A CYCLIC SALT SPRAY TEST

Abstract

The corrosion behavior of galvanized X80 pipeline steel welded joints in a marine atmospheric environment was studied using the cyclic salt spray accelerated corrosion test. The corrosion weight loss, corrosion morphology and corrosion products of samples under different cycles were characterized by means of appearance inspection, SEM and EDS. The results show that with the rupture of the galvanized layer, cracks first appear when the weld metal is exposed for eight days. With the infiltration of the corrosive liquid, pitting pits first appear in the weld metal. In the early stage of corrosion in the heat-affected zone, the fracture degree of the zinc layer is more serious than that in the other two areas. The corrosion products of the zinc layer accumulate irregularly and more pits appear, resulting in early cracks and pitting pits in the later stage. Compared with the first two regions, the base metal shows better corrosion resistance.