Salt Spray Corrosion Performance of X70 Pipeline Steel

The salt spray corrosion testing of X70 pipeline steel was conducted. The changes of morphologies and chemical elements of X70 pipeline steel before and after salt spray corrosion test were observed by SEM and EDS. The results show that pitting corrosion of the sample is relatively serious after the salt spray corrosion, and the uniformity and integrity of the surface of the sample were damaged and many pits were formed on the surface after the salt-spray test. The content of Fe in the sample was high, which could produce active iron atoms. The reaction of active iron atoms with the corrosive medium Cl- ions was the main factor of pitting corrosion.