Experimental study on under-deposit corrosion and its inhibition using electrochemical methods and electronic coupon technique

Abstract

Purpose In this study the aim was to investigate under-deposit corrosion (UDC) behavior and the action effects of amino trimethylene phosphonic acid (ATMP) in the oxygen-contained solution. Design/methodology/approach Electrochemical methods and wire beam electrode techniques were used for the study of ATMP action effect for X65 steel under silica sand and CaCO3 particle deposit. Electronic coupon technique was used for the study of galvanic effect caused by the deposits and the action effect of ATMP. Findings ATMP would cause localized corrosion for the silica sand-covered steel. However, it could inhibit the localized corrosion of the steel beneath CaCO3 particle deposit. Galvanic effect test showed that the galvanic effect caused by the deposits was an important factor for the acceleration of UDC. ATMP had an obvious promotion effect for the galvanic current between bare coupon and silica sand covered coupon and different degrees of localized corrosion were observed beneath both deposits. Originality/value The authors believe that the paper may be of particular interest to the readers of the journal as the measurement methods for the UDC of X65 pipeline steel. The experiment they did in the laboratory found that the inhibitor ATMP has a good inhibition effect for bare steel, but it would accelerate the UDC. Different kinds of deposits would have different influences for the UDC behavior with inhibitor added.

Study on the preparation and corrosion inhibition of Schiff-base self-assembled membranes

“…The diameter of the capacitive reactance arc is positively related to the charge transfer resistance on the surface of the electrode. The larger the diameter of the arc, the lower the corrosion rate and the higher the sustained release efficiency (Xu et al , 2017). It can be seen from the figure that as concentration of copper electrodes increased, the diameter of capacitive reactance arc increased as well.…”

An overview of progresses and challenges of electrochemically integrated multi-electrode arrays for probing localised corrosion in complex environmental conditions

“…This experiment illustrates the need for careful consideration when selecting inhibitors for controlling underdeposit corrosion [67]. Experiments were also conducted using electrode arrays to study underdeposit corrosion of X65 steel exposed to oxygen containing environments [68,69], to investigate corrosion of mild steel under CaCO 3 deposit in the oilfield-produced water [70] and in CO 2 -containing formation water [71]. Copper and aluminium corrosion in highly concentrated sodium chloride solutions with and without solid deposits has also been studied using specially shaped coupons and WBEs [72].…”

Electrochemical Study on the Macro-Cell Corrosion of Pipeline Steel Partially Covered by Different Kinds of Mineral Deposits

“…The mineral deposits always entrain in the oil and gas production water, − resulting in the partial coverage of the pipe bottom. The accumulation of the mineral deposits might cause localized corrosion at six o’clock of the pipe circle, , which is normally defined as under deposit corrosion (UDC). , Due to the inhibition of the ion diffusion beneath the deposition barrier, the local chemical and electrochemical environment beneath the deposit would be different from that of the steel in the bulk solution. , Accordingly, the inhomogeneous surface status beneath the deposit , and the potential difference , between the bare steel and deposit-covered steel are attributed to the main influencing factors for the initiation and propagation of UDC.…”

“…7,8 Due to the inhibition of the ion diffusion beneath the deposition barrier, the local chemical and electrochemical environment beneath the deposit would be different from that of the steel in the bulk solution. 9,10 Accordingly, the inhomogeneous surface status beneath the deposit 11,12 and the potential difference 13,14 between the bare steel and deposit-covered steel are attributed to the main influencing factors for the initiation and propagation of UDC.…”