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Corrosion monitoring is the use of a corrator (corrosion meter) or set of methods [1] and equipment to provide offline or online information about corrosion rate expressed in mpy (mill per year). [ 2 ] - for better care and to take or improve preventive measures to combat and protect against corrosion .
The rate of corrosion (R) is calculated as = where k is a constant, W is the weight loss of the metal in time t, A is the surface area of the metal exposed, and ρ is the density of the metal (in g/cm 3). Other common expressions for the corrosion rate is penetration depth and change of mechanical properties.
Pitting resistance equivalent number (PREN) is a predictive measurement of a stainless steel's resistance to localized pitting corrosion based on its chemical composition. In general: the higher PREN-value, the more resistant is the stainless steel to localized pitting corrosion by chloride .
Iron rusting has a low reaction rate. This process is slow. Wood combustion has a high reaction rate. This process is fast. The reaction rate or rate of reaction is the speed at which a chemical reaction takes place, defined as proportional to the increase in the concentration of a product per unit time and to the decrease in the concentration of a reactant per unit time. [1]
In chemistry, the rate equation (also known as the rate law or empirical differential rate equation) is an empirical differential mathematical expression for the reaction rate of a given reaction in terms of concentrations of chemical species and constant parameters (normally rate coefficients and partial orders of reaction) only. [1]
Chemical kinetics, also known as reaction kinetics, is the branch of physical chemistry that is concerned with understanding the rates of chemical reactions. It is different from chemical thermodynamics , which deals with the direction in which a reaction occurs but in itself tells nothing about its rate.
Zaki Ahmad, in his book Principles of corrosion engineering and corrosion control, states that "Corrosion engineering is the application of the principles evolved from corrosion science to minimize or prevent corrosion". [7] Shreir et al. suggest likewise in their large, two volume work entitled Corrosion. [8]
Pitting corrosion, or pitting, is a form of extremely localized corrosion that leads to the random creation of small holes in metal. The driving power for pitting corrosion is the depassivation of a small area, which becomes anodic (oxidation reaction) while an unknown but potentially vast area becomes cathodic (reduction reaction), leading to ...