Paramagnetic alpha iron transforms into its gamma allotrope at a temperature of_______________?
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Answer: B. 910°C
Explanation
Pure iron undergoes a distinct allotropic phase transformation from body-centered cubic alpha iron to face-centered cubic gamma iron at nine hundred ten degrees Celsius. This specific temperature marks the onset of the crystal structure change during heating of unalloyed iron. Phase boundaries on iron-carbon equilibrium diagrams clearly designate this critical transformation temperature. Allotropy refers to the property of an element existing in two or more different crystal structural forms. Alpha iron is magnetic at lower temperatures, while gamma iron exhibits a non-magnetic face-centered cubic lattice. Phase transformations in iron-based alloys form the scientific foundation of modern heat treatment metallurgy.
Seven hundred seventy degrees Celsius represents the Curie point where alpha iron loses its magnetic properties. Fourteen hundred forty degrees Celsius corresponds to a different high-temperature phase boundary in iron alloys. Fifteen hundred thirty-nine degrees Celsius is the melting point temperature where solid iron turns into liquid.
- Subject
- Engineering
- Category
- Mechanical Engineering
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- —
- Difficulty
- medium
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