Electrochemical noise monitoring of the atmospheric corrosion of steels: identifying corrosion form using wavelet analysis

ABSTRACT

The early stage atmospheric corrosion of T91 and Q235B steels exposed to Tianjin’s urban atmosphere over 20 days was studied using two electrochemical probes via an electrochemical noise (EN) technique. To identify the corrosion process and the corrosion form of the two steels, EN data were analysed by statistics and wavelet transform. The results revealed that the wavelet energy of decomposed EN mainly located at high-frequency level for Q235B steel, whereas it mainly located at the low-frequency level for T91 steel. Analyses of surface images confirmed that Q235B steel underwent uniform corrosion whereas T91 steel suffered from localised corrosion. The obtained noise resistance correlated well with weight loss data.

GRAPHICAL ABSTRACT

KEYWORDS:

• Atmospheric corrosion
• electrochemical noise
• corrosion monitoring
• wavelet transform
• corrosion form

Disclosure statement

No potential conflict of interest was reported by the author(s).

ORCID

Da-Hai Xia http://orcid.org/0000-0003-2336-8564

Additional information

Funding

The authors wish to acknowledge the financial support of the Major State Basic Research Development Program (973 Program) (grant no. 2014CB046805), the National Natural Science Foundation of China (nos. 51131007, 51671144), National Natural Science Foundation of China (51471117) and Key Project of Tianjin Natural Science Foundation (13JCZDJC29500).