Open AccessUSING WIRE BEAM ELECTRODE (WBE) TO EVALUATE THE CORROSION BEHAVIOR OF ND STEEL IN ACID MEDIUM
Author(s) -
Bo Zhao,
Yuxin Yu,
Jing Guo,
Tingdong Zhou,
Shiwen Zou,
Tao Xu
Publication year - 2020
Publication title -
materials and corrosion engineering management
Language(s) - English
Resource type - Journals
ISSN - 2716-7100
DOI - 10.26480/macem.02.2020.27.30
Subject(s) - corrosion , cathode , materials science , anode , dissolution , electrode , dew point , metallurgy , partial pressure , composite material , chemical engineering , chemistry , oxygen , physics , organic chemistry , meteorology , engineering
In this article, wire beam electrode (WBE) was used to evaluate the corrosion behavior of ND steel in environmental acid atmosphere with different partial pressure of CO2. Meanwhile, corrosion products and surface morphology analysis also used to support this research. The results showed that the corrosion behavior began from the edge of droplet in dew point corrosion, and gradually spread to the center of it. The spread speed would be increasing with CO2 partial pressure enhance, which was 24h in 5% CO2 and 4h in 50% CO2. Corrosion current density in the edge of droplet can form the “cathode-anode-cathode ring” structure and disappears gradually as the corrosion time was going. Corrosion morphology observation results showed three ring shapes region and different elemental composition of different corrosion products, which is correspondence with the “cathode-anode We-cathode ring” structure measured in WBE experiments. The results showed that the reaction gradually transferred to the uniform corrosion on electrode surface when the dew point corrosion reaction reaching the late stage. It comes from the dissolution, diffusion and reaction of gaseous corrosion medium of CO2 and O2.