Pitting corrosion in pipeline steel weld zones

Probabilistic Pitting Corrosion Risk Assessment of Welded Offshore Steel Pipelines

Steel structures continuously exposed to offshore marine environments are prone to corrosion. This can be of major economic and perhaps of environmental significance. The risk of these scenarios occurring can be assessed using good quality data, good quality corrosion and pitting models and structural reliability assessment. Recently, improved models for the prediction of longer term corrosion ...

A Statistical Study on the Effect of Hydrostatic Pressure on Metastable Pitting Corrosion of X70 Pipeline Steel

Hydrostatic pressure effects on pitting initiation and propagation in X70 steel are investigated by evaluating metastable pitting probability using electrochemical methods and immersion corrosion tests in containing chlorine ion solution. Potentiodynamic tests indicated that hydrostatic pressure can decrease the breakdown potential and lead to a reduced transpassivity region. Metastable test re...

IMPROVING PITTING CORROSION OF 304 STAINLESS STEEL BY ELECTROPOLISHING TECHNIQUE

Several surface modification techniques such as ion implantation, surface laser melting, have been employed to improve pitting corrosion resistance of stainless steel. Electropolishing is a technique in which the surface roughness is eliminated through a selective electrochemical dissolution. The effect of electropolishing on pitting corrosion of 304 stainless steel (SS) was investigated employ...

Stainless steel pitting and early-stage stress corrosion cracking under ultra-low elastic load

Pitting Initiation and Propagation of X70 Pipeline Steel Exposed to Chloride-Containing Environments

Inclusion-induced pitting initiation mechanisms in X70 steel were investigated by scanning electron microscopy, scanning Kelvin probe force microscopy (SKPFM), immersion and electrochemical polarization tests in chloride-containing ion solutions. There are three inclusion types in the X70 steel. Corrosion test results indicated that pitting corrosion resistance of type A inclusion < type C incl...