Lecture 8

Corrosion: Introduction – Definitions and Types

Corrosion can be viewed as a universal phenomenon, omnipresent and omnipotent. It is there everywhere, air, water, soil and in every environment, we encounter.
There is no single figure for loss to the nation due to corrosion. It can be a minimum of 3.5% of the nation?s GDP. Losses due to corrosion could be around Rs. 2.0 lakh crores per annum in India. Corrosion costs manifest in the form of premature deterioration or failure necessitating maintenance, repairs and replacement of damaged parts.
In the US, total direct cost of corrosion is estimated at about 300 billion dollars per year; which is about 3.2% of domestic product. Corrosion has a huge economic and environmental impact on all facets of national infrastructure; from highways, bridges, buildings, oil and gas, chemical processing, water and waste water treatment and virtually on all metallic objects in use. Other than material loss, corrosion interferes with human safety, disrupts industrial operations and poses danger to environment. Awareness to corrosion and adaptation of timely and appropriate control measures hold the key in the abatement of corrosion failures.
Definitions:

Corrosion is the deterioration or destruction of metals and alloys in the presence of an environment by chemical or electrochemical means.
In simple terminology, corrosion processes involve reaction of metals with environmental species.
Corrosion: Introduction – Definitions and Types

Corrosion can be viewed as a universal phenomenon, omnipresent and omnipotent. It is there everywhere, air, water, soil and in every environment, we encounter.
There is no single figure for loss to the nation due to corrosion. It can be a minimum of 3.5% of the nation?s GDP. Losses due to corrosion could be around Rs. 2.0 lakh crores per annum in India. Corrosion costs manifest in the form of premature deterioration or failure necessitating maintenance, repairs and replacement of damaged parts.
In the US, total direct cost of corrosion is estimated at about 300 billion dollars per year; which is about 3.2% of domestic product. Corrosion has a huge economic and environmental impact on all facets of national infrastructure; from highways, bridges, buildings, oil and gas, chemical processing, water and waste water treatment and virtually on all metallic objects in use. Other than material loss, corrosion interferes with human safety, disrupts industrial operations and poses danger to environment. Awareness to corrosion and adaptation of timely and appropriate control measures hold the key in the abatement of corrosion failures.
Definitions:

Corrosion is the deterioration or destruction of metals and alloys in the presence of an environment by chemical or electrochemical means.
In simple terminology, corrosion processes involve reaction of metals with environmental species.