Definition

1. Noun:
   • A nonmagnetic allotrope of iron: Gamma iron is a specific crystalline form (allotrope) of the element iron. Its key distinguishing physical property is that it is nonmagnetic.
   • The basis of austenite: In metallurgy, gamma iron forms the fundamental crystal structure for the phase known as austenite, which is a solid solution of carbon and other elements in gamma iron.
   • Stable within a specific temperature range: This form of iron is only stable at very high temperatures, specifically between 906 and 1403 degrees Celsius.

Usage Examples

• Noun:
  • The steel was heated until its structure transformed into gamma iron.
  • Austenite is a solid solution of carbon in gamma iron.
  • The property of being nonmagnetic is a key identifier for gamma iron.

Advanced Usage

• "Gamma iron phase": Refers specifically to the region on an iron-carbon phase diagram where this allotrope is stable.
  • The alloy must be quenched rapidly from the gamma iron phase to form martensite.

Variants and Related Words

• Austenite (n): The solid solution of carbon in gamma iron; a crucial microstructure in many steels.
  • The presence of austenite at room temperature is achieved in some stainless steels.
• Allotrope (n): Each of two or more different physical forms in which an element can exist.
  • Diamond and graphite are allotropes of carbon.

Synonyms

• Austenitic iron: (Technical synonym) Often used interchangeably in metallurgical contexts to emphasize its role as the basis of austenite.
• FCC iron: (Technical synonym) Refers to its Face-Centered Cubic crystal structure.

Notes on Meaning

• This term is highly specialized to the field of materials science and metallurgy. In common language, "iron" typically refers to the metal in its general form, not this specific high-temperature allotrope. The definition is precise and scientific.

Noun

1. a nonmagnetic allotrope of iron that is the basis of austenite; stable between 906 and 1403 degrees centigrade