Resistência à corrosão dos aços inoxidáveis austenítico e super austenítico em água de poço sintética medida por potencial escalonado

Abstract

The pre-salt region is very hostile to the materials used in such environment due to some factors found under the pre-salt layer such as: corrosive gases, oil formation water, high pressures and so on. In order to evaluate only the effect of the oil field formation water on the corrosion resistance of austenitic stainless steels in such environment, two austenitic and two superaustenitic stainless steels were tested in synthetic oil field formation water using the electrochemical technique called step potential. In this technique, potential values (vs Ag/AgCl ) is applied in steps of 50 mV every 1 h until a current of 1 mA was achieved. The results showed that the common austenitic stainless steels are not suitable for the use in chloride-containing environment as the one found in the pre-salt region. They exhibited pitting corrosion. The superaustenitic stainless steels tested exhibited a good corrosion resistance in this medium and can be a solution for the use under some pre-salt conditions.