Get Knowledge Of Steel Corrosion

Dec 8, 2014

Steel corrosion not only make the sectional area decreased, but also reduce its performance and even scrapped. Besides if it has been appeared corrosion pit, that will make stress concentration and accelerate structural damage. Especially impact load and cyclic alternating loads, it will appear phenomenon of corrosion fatigue. At this time, the fatigue strength of the steel will be reduced greatly, and even the emergence of brittle fracture.

According to the corrosion mechanism, steel corrosion can be divided into two kinds, they are chemical corrosion and electrochemical corrosion. Chemical corrosion is means that steel reaction with surrounding medium directly, and then producing corrosion. These corrosion are mostly caused by oxidation, steel surface will form loose oxide. Electrochemical corrosion is always caused of the steel contact with electrolyte solution. They form micro battery and caused corrosion finally.

There are many factors that lead to steel corrosion. They mainly include humidity and oxygen in environment, acid, alkali, salt in the medium, steel surface condition and its chemical composition. Some halogen ions, especial chloride ion can damage protective film and improve the reaction of corrosion. So the corrosion may be developed quickly.