Definition - What does Corrosion Resistance mean?
Corrosion resistance refers to the resistance a material offers against the reaction with adverse elements which can corrode the material. Various materials have this property intrinsically, depending upon their corrosion resistance rate. Some other methods can also be used to resist corrosion such as painting, hot dip galvanizing and the combination of these methods with coating.
Essentially, corrosion is the process in which a material is oxidized by the environment and loses electrons in its result. Therefore, corrosion resistance is the capability to hold that binding energy of metal and withstand the deterioration and chemical breakdown that occurs during surface exposure to such an environment.
Corrosionpedia explains Corrosion Resistance
Usually the resistance to corrosion is expressed in terms of corrosion rate and measured in units of millimeter per year or "mils." These measurements for resistance to corrosion attack are taken in a particular environment at defined operating conditions, pressure, temperature and fluid velocity.
Besides intrinsic corrosion resistance, the resistance to corrosion of a metal can be increased by applying different methods such as cathodic protection, coating, painting and applying a corrosion inhibitor. There are no materials that are resistant to all corrosion in all environments. Materials must be matched to the environment they will experience. Corrosion resistances for metals are estimated and data used to check the sustainability of a metal in a particular environment.
Protective coatings are the most widely used corrosion control technique. Essentially, protective coating materials are corrosion resistant and are a means for separating the surfaces that are susceptible to corrosion attack. Whereas cathodic protection interferes with the natural action of electrochemical cells that are responsible for corrosion. Cathodic protection can be effectively used to resist corrosion of surfaces that are immersed in water or exposed to soil. In material selection for corrosion control, corrosion resistance is an important factor to consider. The materials most resistant to corrosion are those for which corrosion is thermodynamically unfavorable. Some metals have naturally slow reaction kinetics, even though their corrosion is thermodynamically favorable. These include metals such as zinc, magnesium and cadmium. Thus, a materials' own resistance to corrosion or protective methods to arrest corrosion fall under the category of corrosion resistance.