Search

The influence of different types of precipitation on the corrosion behavior was investigated in three aluminum-siliconmagnesium alloys. The microstructures of the alloys were studied through optical (OM) and scanning electron microscopy (SEM). The structures consisted of an α-Al solid solution matrix, Si eutectic crystals, secondary phases AlFeSi and AlMgFeSi (Chinese script), as well as Mg2Si. The corrosion behavior was examined with the use of a potentiodynamic polarization test followed by a SEM surface analysis. The results indicate that all the analyzed samples were in the passive state and AlSi10Mg was less reactive in the corrosive environment.

Corrosion tests were carried out to study the corrosive behaviour of medium carbon steels with a ferrite-pearlite microstructure during exposure to a synthetic flowback facturing fluid saturated with carbon dioxide. Metallographic investigations, screening tests, surface morphology investigations and identification of surface products were used for this purpose. The results obtained indicate that the corrosion of N80-1 carbon steel was significantly lower than that of K55 carbon steel. The layer of corrosion products consisted of an outer layer of carbonates and an inner layer with cementite lamellas. Higher grain refinement of N80-1 steel compared to that of K55 steel caused the formation of a denser, more homogenous layer of corrosion products, which significantly reduced the corrosion of the base material. [ABSTRACT FROM AUTHOR]