New Conservation Materials on the Base of Colza Oil for the Steel Protection against Atmospheric Corrosion

Abstract

Protective efficiency of the composition on the base of low erucic colza oil has been studied against the carbon steel corrosion in the salt solution (3 % NaCl), thermo-moisture chamber and the natural conditions. The following compositions have been used:1. Colza oil (CO) and its components without the inhibiting additives; 2. CO with the synthetic fat acids bottoms (SFAB) additive (1-10 wt.%); 3. CO with the anticorrosion additive IFHAN 29-A (20 wt.%); 4. CO with zinc micro powder filler (50 wt.%); 5. CO with Zn micro powder (50 wt.%) and micro graphite (≤ 1 wt.%); 6. CO with Zn micro powder (50 wt.%) and multiwalled carbon nano tubes (≤ 1 wt.%). The corrosion tests, electrochemical measurements have been conducted. Moisture absorption by the investigated compositions, their adhesion and cohesion with respect to steel surface were estimated.Protective coatings of CO and its components are not effective in the presence of the chloride ions, but provide the 90 % protective efficiency in natural conditions. The compositions with SFAB and IFHAN 29-A show the protective effect equal to 40-50 % in chloride media and 99 % in a thermo-moisture chamber and natural conditions. The presence of Zn powder in the compositions allows to reach a high protective effect (up to 99 %) irrespective of the nature of the solvent-support (colza oil or its components). Addition of the multiwalled carbon nano tubes decreases the protective effect of the compositions.

Influence of a Show Case Polish Coating on Corrosion Resistance of Mild Steel in Simulated Concrete Pore Solution

“…Electrochemical studies such as polarization study and AC impedance spectra 1,2,3,4,5,9,10,11,12,16,17,20,21,24,25,27,28,29 are useful in measuring the corrosion resistance of mild steel in various test solutions.…”

Estimation of Protective Efficiency of Oil-based Compositions Containing Zinc and Graphite Powders Against Steel Atmospheric Corrosion

“…These films are penetrated by dissolved oxygen, water steam, SO 2 (7) and by substantially more large particles -molecules of the organic inhibitors presenting in the solution and showing protective action with reference to steel covered by the oil film (8). It is shown (9) that the boundary wetting angles of carbon steel and copper by the individual oil I 20-A or its compositions with SAS are equal to 7 -18 o . In the same time a water drop or drop of 3% NaCl solution on the metal surface shows the boundary wetting angles equal to 77 -82 o .…”

“…However the cathodic and anodic reactions are impossible on the metal surface without water but they proceed nevertheless. It is natural to suppose that the pores (capillaries) pierce through the oil films and they are filled in partly or completely with the solution (9). On the capillary bottom locating on the metal surface the double electrical layer (DEL) is formed.…”