Stainless steel overview: glossary

Age Hardening

Martensitic stainless steels are hardened by heating above their critical temperature, holding them at heat to insure uniform temperature, and cooling them rapidly by quenching in air or oil.


AISI (American Iron and Steel Institute)

A North American trade association with 50 member companies and over 100 associate members. These companies represent the United States, Canada, and Mexico in all aspects of the steel industry.


Alloying Element

The adding of any metallic element in stainless steel production in order to increase hardness, strength, or corrosion resistance. Molybdenum, nickel, and chromium are common alloying elements in stainless steel.


Alloy Surcharge

The producer’s selling price plus a surcharge added to offset the increasing costs of raw materials caused by increasing alloy prices.


Annealing (Solution Annealing)

A process of heating cold stainless steel to obtain maximum softness and ductility by heat treatment which also produces a homogeneous structure (in austenitic grades) or a 50/50 mixture of austenite and ferrite (in duplex grades). It relieves stresses that have built up during cold working and insures maximum corrosion resistance. Annealing can produce scale on the surface that must be removed by pickling.


Anodic Protection

Polarization to a more oxidizing potential to achieve a reduced corrosion rate by the promotion of passivity.


Argon-Oxygen Decarburisation (AOD)

A process of further reducing the carbon content of stainless steel during refinement. AOD is closely related to Electric Arc Furnaces (EAF), but has a shorter operating time and requires lower temperatures.


Austenitic Stainless Steel

Non-magnetic stainless steels that contain nickel and chromium sufficient to develop and retain the austenitic phase at room temperature. Austenitic stainless steels are the most widely used category of stainless steel.


Automatic Gauge Control

A hydraulic roll force system where stainless steel makers can monitor a stainless steel sheet’s thickness while it moves through the mill. The computer's gap sensor adjusts and monitors the thickness 50 to 60 times per second.