Simulation Research on the Corrosion Behavior of X70 Pipeline Steel under Dynamic AC Interference
In order to provide reference for the anti-corrosion design of pipelines near electrified railways,the characteristics of AC dynamic in-terference parameters near pipelines of different railway types were studied on the basis of pipeline monitoring data.The corrosion behavior of buried X70 pipeline steel under dynamic AC interference in high-speed and ordinary railways was studied and analyzed through using a dynam-ic AC corrosion simulation test device under cathodic protection.Results showed that in a typical dynamic interference cycle,a higher dynamic AC interference current density resulted in a higher corrosion rate of X70 steel under the same cathodic protection potential.When the dynamic AC current density was higher than 100 A/m2,the corrosion rate was higher than 0.03 mm/a under any cathodic protection conditions.Under dynamic communication interference,as the level of cathodic protection increased,the corrosion rate presented a"saddle shaped"pattern,first decreasing and then increasing.Only when the AC current density was 30 A/m2 and the cathodic protection level was between-0.90 and-1.15 V(vs CSE),the corrosion rate was less than 0.03 mm/a.Furthermore,even if the pipeline was in an effective cathodic protection state,corrosion would occur under dynamic communication interference.
X70 steelcathodic protectiondynamic AC interferencecorrosion ratecorrosion morphologycorrosion products