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3.1 Explain how you will prevent damage to a file when conducting a filing test on a hard metal - NSC Mechanical Technology Automotive - Question 3 - 2019 - Paper 1
Question 3
3.1 Explain how you will prevent damage to a file when conducting a filing test on a hard metal. 3.2 What is the purpose of the heat treatment of steel? 3.3 Give T... show full transcript
Worked Solution & Example Answer:3.1 Explain how you will prevent damage to a file when conducting a filing test on a hard metal - NSC Mechanical Technology Automotive - Question 3 - 2019 - Paper 1
Step 1
Explain how you will prevent damage to a file when conducting a filing test on a hard metal.
Answer
To prevent damage to a file during a filing test on a hard metal, it is essential to use proper filing techniques. This includes filing with the correct pressure to avoid excessive wear on the file. The tip or edge of the metal should be filed to distribute the load evenly, reducing localized wear. Additionally, applying chalk to the file surface can reduce friction, thereby minimizing heat and wear on the file.
Step 2
What is the purpose of the heat treatment of steel?
Answer
The purpose of the heat treatment of steel is to alter its properties and grain structure. Heat treatment helps in improving the hardness, ductility, and overall mechanical properties of steel, making it suitable for various applications.
Step 3
Give TWO reasons for tempering hardened steel.
Answer
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To reduce the brittleness caused by the hardening process, ensuring that the steel can withstand mechanical stress without breaking.
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To relieve strain induced during the hardening process, allowing the material to achieve a more stable and usable form.
Step 4
Describe how the following heat treatment processes are carried out on steel: 3.4.1 Annealing
Answer
In the annealing process, the steel is heated to a specific temperature suitable for the type of steel being treated. The steel is then soaked at that temperature for a predetermined duration to ensure uniform heating. After soaking, the steel is cooled very slowly, which helps to produce maximum softness and enhances its ductility.
Step 5
Describe how the following heat treatment processes are carried out on steel: 3.4.2 Hardening
Answer
For hardening, the steel is heated to a temperature slightly above the upper critical temperature (Ac3). It is then maintained at that temperature to allow for proper austenitization. Once the appropriate time has passed, the steel is quickly cooled, usually by quenching in a rapid cooling medium, such as water or oil, to increase its hardness.