THE INFLUENCE OF WATER CONCENTRATION ON THE CORROSION OF LOW ALLOY STEELS IN THE SYSTEM METHANOL – ETHYLENE GLYCOL – n-BUTIRIC ACID

Abstract

The behaviour of three types of steel with a variable carbon content (from 0.2 to 0.4% ) is studied in medium of methanol – 10% ethylene glycol – 5% n-butiric acid with water concentration between 1% to 5% . The weight loss are measured and the gravimetric figure K (g·m-2·h-1) and the penetration figure P (mm·m-2·year-1) are calculated. Also, the kinetic corrosion parameters are established. The methods used for identification and analysis of the corrosion compounds are: elemental analysis, IR. spectra and X–ray diffraction. Also, by electron microscopy, a corrosion mechanism is assigned.