Stainless 08X18H10T and Low-Alloyed 15X1M1Ф Steels Protection from Corrosion with Emulsions of Thermostable Amines

Abstract

Chromium - nickel (08X18H10T) and chromium - molybdenum - vanadium (15X1M1Ф) steels together with emulsions of corrosion inhibitors - thermo stable amines have been investigated. Stainless steel was investigated in a aggressive medium of monoethanolamine (MEA) having absorbed CO2. Effectiveness of steel corrosion inhibitors Kotamina P/2A, JM-T HTDOX, JM-T/CD and Kotamina Plus! was evaluated using electrochemical, optical and X-ray diffraction analysis methods. Anodic polarization curves of samples, passivated at 200 – 500 °C temperature were recorded and limits of passive state from –0.10 to +0.40 V for stainless steel and from –0.13 to +0.80 V for low-alloyed steel have been established. Kotamina JM-T/CD emulsion decreases corrosion rate of stainless steel in aggressive medium ∼7 times according to reference sample. It was established that emulsion of Kotamina Plus! is the most effective corrosion inhibitor of the steel. Cathodic polarization method has been selected for modelling corrosion processes taking part in different medium. Current of corrosion of 15X1M1Ф steel was calculated using Tafel's experimental dependence. It was established, that decrease of corrosion current in medium with Kotamina Plus! depends on inhibitor screening effect.