A Novel Multielectrode Sensor for High-Temperature Corrosion Monitoring

摘要

Existing coupled multielectrode array sensors (CMAS) have been used as real-timernmonitors for localized corrosion. However, most of these devices have an upper operatingrntemperature limit of approximately 70 ℃. At temperatures above 70 ℃, crevice formationrnbetween the electrode and the mounting epoxy may result in inaccurate high corrosion rates. Inrnthis paper, development of a novel, electrochemical sensor for monitoring corrosion of alloys atrntemperatures above 100 ℃ is presented. Sensing electrodes were made of stainless steel,rnaluminum, titanium and nickel-based alloys with a diamond-like carbon thin film deposited onrnthe sensing electrodes. The effectiveness of the diamond-like carbon film to protect the alloyrnelectrodes was evaluated and demonstrated in corrosive solutions with a pH range of 2.5 to 10 atrn130-250 ℃. The effective corrosion monitoring capability of the new electrochemical sensors atrnhigh temperatures is attributed to the high electrical impedance and chemical inertness of therndiamond-like carbon film.