It is indicated that the passive film was broken down by the absorption of chloride ion from feedwater on its surface, resutling in pitting.

• 结果表明：给水中氯离子含量严重超标，由干它的吸附作用破坏了局部表面保护膜，形成点蚀源；给水中氧含量超标，使炉管发生氧致腐蚀，使蚀点加深，甚至穿孔。