Metal Glossary

General Corrosion

Corrosion in which the whole exposed surface is attacked by the corrosive medium at a broadly uniform rate. All corrosion is deleterious but general corrosion is more predictable and may be readily monitored and so managed. This is in contrast to the localised forms of attack such as pitting corrosion, crevice corrosion, inter-granular corrosion and stress corrosion cracking where the attack in very localised and can be intense causing unexpected, premature, failure.

Related terms: Pitting Corrosion, Crevice Corrosion, Inter-granular Corrosion, Stress Corrosion Cracking

Grain Size

A measure of the area or volume of grains (crystals) in polycrystalline material. Grain size is reported in a number of ways:- • Number of grains per unit of area or volume, • Average diameter, • As a grain size number derived from area measurements and comparison with a standard chart.

Grain Structure

The shape, size, distribution and disposition of metal crystals and their crystal structure within a solid metal or alloy.

Guillotining

The cutting of plate, sheet or strip to size or length using guillotine shears. For the guillotining of stainless steels, as compared to mild/carbon steels, the shearing blades need to be sharper and have a reduced clearance.