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(a) (i) Outline any two reasons for the heat treatment of metals - Leaving Cert Engineering - Question 3 - 2014
Question 3
(a) (i) Outline any two reasons for the heat treatment of metals. (ii) Name three heat treatment processes that may be applied to steels. (b) Describe two heat ... show full transcript
Worked Solution & Example Answer:(a) (i) Outline any two reasons for the heat treatment of metals - Leaving Cert Engineering - Question 3 - 2014
Step 1
Outline any two reasons for the heat treatment of metals.
Answer
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To improve material properties: Heat treatment enhances properties such as hardness, tensile strength, and ductility, which make metals more suitable for various applications.
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To soften metals before cold working: Metals may be heat treated to soften them, allowing easier manipulation during processes such as forging and forming.
Step 2
Name three heat treatment processes that may be applied to steels.
Answer
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Hardening: A process that increases hardness by heating and then rapidly cooling the steel.
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Annealing: This involves heating the steel to a specific temperature and then allowing it to cool slowly to relieve internal stresses.
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Tempering: This process reduces brittleness by reheating hardened steel to a lower temperature.
Step 3
Describe two heat treatment processes that are carried out on the file shown.
Answer
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Hardening: The file is initially heated to a cherry red color to alter its microstructure. After achieving the correct temperature, it is cooled rapidly in water. This process makes the file significantly harder, improving its ability to cut.
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Tempering: After hardening, the file can become brittle. To reduce this brittleness, it is reheated to a lower temperature, usually below the hardening temperature. Then, it is allowed to cool down, which also helps in providing a more controlled hardness.
Step 4
State two reasons why it is essential to wear safety goggles when heat treating metals.
Answer
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Protect the eyes from heat splashes or rising steam: During the heat treatment process, there may be splashes of hot liquid or steam, which can cause severe eye injuries.
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Protect the face and eyes from hot particles: Heat treatment can produce sparks or flying particles which can harm the eyes and face if protective eyewear is not worn.