Effect of environmental pressure on the corrosion behavior of sacrificial anode magnesium alloy in simulated cementing cement hole solution

The effect of environmental pressure on the corrosion behavior of sacrificial anode magnesium alloys was systematically investigated when immersed in simulated cementing cement hole solutions (SCCHS) with a concentration of 0.15 mol/L chloride ions under different environmental pressures. The experiment results showed that the increased environmental pressure was beneficial to form a dense deposition film on the surface of protected P110 steel when coupled with Mg alloys. At the same time, the corrosion speed of coupled Mg alloys accelerated and the galvanic current of the coupled P110/Mg alloys decreased with the increasing environmental pressure, which resulted in a lower anode protection efficiency. Furthermore, a possible “pressure-induced dense film formation” mechanism was in detail discussed, which helps optimize the design and performance of corrosion protection systems. Graphical abstract