This article describes the various environments affecting corrosion performance, corrosion protection, and corrosion control. These include freshwater environments, marine environments, and underground environments. The article provides information on corrosion in military environments and specialized environments, representing less-well-known environments with more limited applications.

Corrosion is classified into two categories: corrosion that is not influenced by any other process and corrosion that is influenced by another process such as the presence of stresses or erosion. This article discusses uniform corrosion, localized corrosion, metallurgically influenced corrosion, and microbiologically influenced corrosion, which fit under the classification of corrosion that is not influenced by any outside process. It also explains mechanically assisted degradation and environmentally induced cracking, which fit under the classification of corrosion that is influenced by an outside process.

A corrosionist refers to a corrosion engineer, a corrosion technician, a corrosion scientist, a chemist, a physicist, an electrical engineer, a mechanical engineer, a coatings or plastics salesperson, a corrosion consultant, or a plant operator. This article presents an overview of statistical inference and addresses the commonly used statistical tools and tests. It describes the science and engineering of materials, including metals, polymers, and ceramics. The article explores the principles of various surface-sensitive techniques and the usefulness and limitations of these techniques. The techniques are divided into those that provide insight into surface topography and surface structure, and those that provide understanding of chemical nature and identity. The article presents a list of web sites and print media addressing corrosion and related topics in five different areas: societies and associations; corrosion standards, specifications, and recommended practices; sources of corrosion information; corrosion databases and data compilations; and other web resources.

This article presents common conventions and definitions in corrosion, electrochemical cells, cathodic protection (CP), electricity, and oxidation. Evans diagrams for impressed current CP in neutral or basic environment and galvanic or sacrificial CP, in both neutral or basic environment and acidic environment, are illustrated.

Simulated service testing is the most reliable predictor of corrosion behavior that is important for specific objectives. These include materials selection, predicting the probable service life of a product or structure, evaluating new commercial alloys and processes, and calibrating laboratory corrosion tests in short of in-plant tests and actual service experience. This article provides a detailed discussion on the types of atmospheres used in simulated service testing. It describes the specifics of atmospheric-corrosion test that include equipment, test arrangement, and test specimen; factors affecting atmospheric corrosion; and evaluation of exposed atmospheric-corrosion panels. The article concludes with a discussion on the empirical model used for analyzing the atmospheric-corrosion measurements for estimating the service life of the part being evaluated.