Dynamic measurements of corrosion rates at high temperatures in high electrical resistivity media

•Measured dynamic corrosion rates of a metal in mock crude at high temperatures.•Demonstrated the efficacy of a gallium orthophosphate microbalance in high resistivity media.•Results showed that NAC of iron began with pitting of iron’s air-formed oxide.

A gallium orthophosphate crystal microbalance makes possible rapid measurements of dynamic corrosion rates at high temperatures in high electrical resistivity media. The crystal microbalance has allowed for the first time the determination of time resolved corrosion rates of iron immersed in an electrically insulating oil with naphthenic acid at high temperature (270 °C).