Effect of free carbon (graphite) in iron: hardness and structure Free (graphitic) carbon present in iron affects mechanical character and appearance. Choose the most appropriate description.
Mechanical Engineering
Engineering Materials
Difficulty: Easy
Choose an option
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ASoft and gives a coarse-grained crystalline structure
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BSoft and gives a fine-grained crystalline structure
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CHard and gives a coarse-grained crystalline structure
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DHard and gives a fine-grained crystalline structure
Answer
Correct Answer: Soft and gives a coarse-grained crystalline structure
Explanation
ConceptIn irons containing free graphite (e.g., grey cast iron), graphite flakes reduce strength and hardness and promote a coarser-looking fracture. The material is relatively soft and exhibits a coarse-grained, crystalline gray appearance.
Final AnswerSoft and gives a coarse-grained crystalline structure