CORROSION MONITORING OF A WATER BASED ROLLING FACILITY WITH COUPLED MULTIELECTRODE ARRAY SENSORS AND THE CORRELATIONS WITH OTHER PROCESS VARIABLES: CONDUCTIVITY, PH, TEMPERATURE, DISSOLVED OXYGEN AND CORROSION POTENTIAL

摘要

Coupled multielectrode array sensors(CMAS) with multielectrode corrosion analyzer and temperature monitoring capability were used along with an Isfet type pH probe, a process contact conductivity probe, and dissolved oxygen probe to monitor data over one year in an Alcoa rolling mill coolant system. During this time several excursions of various parameters occurred, indicating chemical and possible electrical causes of corrosion. A CMAS type crevice type probe was also used to investigate crevice corrosion (a common problem on piping and fixtures coming in external contact with the mill coolant) and was used to determine material/engineering recommendations for prevention of corrosion in rolling mills.