ferritic

Ferritic is a term used in metallurgy to describe iron-containing materials that have the ferrite crystal structure, a body-centered cubic lattice. In this sense, ferrite refers most often to alpha-iron, the magnetic BCC form of iron stable at room temperature and up to about 912°C. Ferritic materials include pure iron, low-carbon steels where ferrite is the dominant phase, and a class of stainless steels with a predominantly ferritic microstructure.

In steel, ferrite is a relatively soft, ductile phase that dissolves only a very small amount of carbon. It forms a continuous matrix that can coexist with other phases such as cementite or austenite, and its carbon solubility decreases as temperature falls, influencing transformations and mechanical properties. The overall microstructure—ferrite, pearlite, martensite—determines strength and hardness.

Ferritic stainless steels are a widely used subclass of stainless steels characterized by a ferritic microstructure. They typically contain 10.5–30% chromium, with low carbon and little to no nickel. They are magnetic and not hardenable by heat treatment. They offer resistance to corrosion and to stress-corrosion cracking in some environments, balanced by generally lower toughness at low temperatures and poorer high-temperature creep resistance compared with austenitic grades, and they are often more affordable.

Outside steels, ferritic describes the ferrite phase in cast irons and other iron-based alloys, where the ferritic matrix influences mechanical properties and magnetic behavior.