Corrosion behavior and passivation protection mechanism on different zone of high-nitrogen steel weld

摘要

In this paper, the passivation adsorption behavior above different corrosion defects on weld surface were investigated. The corrosion behavior and corrosion resistance of each weld zone were analyzed and compared. By anodic passivation interception method, it is observed that the damaged dendrite structure and the corrosion pitting received varying degrees of protection by passive film. This specific protective mode is related to the matrix microstructure and corrosion characteristic in each weld zone. Under the same passivation potential, the protection degree of passive film on HAZ is relatively weak. The passive film above weld seam and base metal own higher metallic oxides intensity and better covering protection mechanism. With the addition of Mocontaining welding wire, the weld passive film surface accumulates new adsorptive Mo4+/Mo6+ oxides.