An on-line electrical resistance corrosion monitor for studying flow assisted corrosion of carbon steel under high-temperature and high-pressure conditions

An in-situ corrosion rate monitor using a carbon steel tube, a carbon steel rod or a carbon steel wire as the sensing element has been developed. The monitor was tested both in an inert system at room temperature and in a high-temperature and high-pressure loop with LiOH solution. Experimental results from the room temperature tests showed that the calculated corrosion rate or thinning rate based on the resistance signal of the carbon steel sensing element agreed well with the measured values. Experimental results from the high-temperature tests showed that the corrosion monitor responded to the corrosion rate changes when air or sulfuric acid was added. The precision of the monitor under the simulated nuclear coolant conditions was found to be ±0.04 microm to ±1 microm in terms of thickness change. The variation in precision is dependent upon the dimension of the sensing element