cementite
A microscope reveals the needle-like structure of cementite in polished steel.
Noun: 1. A hard, brittle chemical compound of iron and carbon: Cementite is an intermetallic compound with the chemical formula Fe₃C. It is a primary constituent of steel and cast iron, contributing significantly to their hardness and strength but also to brittleness.
Cementite is a technical term used primarily in metallurgy and materials science. * It is used to describe a specific phase within the microstructure of ferrous alloys. * It is often discussed in contrast with other phases like ferrite (a softer, more ductile form of iron).
- Noun:
- The high carbon content in this steel leads to the formation of cementite along the grain boundaries.
- The hardness of white cast iron is primarily due to the presence of a continuous network of cementite.
- Under the microscope, the dark-etching pearlite colonies contain alternating layers of ferrite and cementite.
- "Cementite network": A microstructure where cementite forms a continuous, brittle skeleton, often found in high-carbon cast irons.
- "Spheroidized cementite": A heat-treated condition where the cementite forms into rounded particles (spheroids) within a ferrite matrix, improving machinability and ductility.
- Iron carbide: A synonymous term for cementite, emphasizing its chemical composition.
- Pearlite: A common microstructure in steel consisting of alternating layers of ferrite and cementite.
- Ledeburite: A eutectic mixture of austenite and cementite found in cast irons.
- Iron carbide (Fe₃C)
Cementite is a metastable compound; given sufficient time at elevated temperatures, it can decompose into iron and graphite (carbon). Its presence and morphology are critical in determining the mechanical properties of steel and cast iron.
A microscope reveals the needle-like structure of cementite in polished steel.
- a chemical compound that is a constituent of steel and cast iron; very hard and brittle