Influence of Ca~(2+) and Mg~(2+) on Corrosion Rate of N80

Corrosion mechanism for N80 steel in the CO_2 and H_2S saturated solution with Ca~(2+)and Mg~(2+)in an autoclave was studied using the techniques of SEM and XRD.The results showed that the corrosion of N80 steel was severe in the solution with CO_2/H_2S and high degree of mineralization,and the corrosion rate decreased firstly and increased subsequently with the increase of Ca~(2+)and Mg~(2+).The corrosion product film peeled off and pitting corrosion occured with the increase of thickness and internal stress of corrosion product film.