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Answer any two of the following: (i) Describe the heat treatment process of normalising - Leaving Cert Engineering - Question 1 - 2014
Question 1
Answer any two of the following: (i) Describe the heat treatment process of normalising. (ii) Distinguish between eutectic point and eutectoid point. (iii) Explai... show full transcript
Worked Solution & Example Answer:Answer any two of the following: (i) Describe the heat treatment process of normalising - Leaving Cert Engineering - Question 1 - 2014
Step 1
Describe the heat treatment process of normalising.
Answer
Normalising is a heat treatment process that involves heating steel to a temperature of about 40°C above its upper critical temperature, followed by air cooling. This process allows the grain structure to become more uniform, resulting in improved ductility and strength. The cooling process relieves internal stresses that may have developed during prior processes such as welding or casting.
Step 2
Compare the main properties of the steel at X, which has 0.3% carbon, and the steel at Y, which has 1.5% carbon.
Answer
Steel at X with 0.3% carbon is classified as mild steel, which is more ductile and does not harden easily. It is typically used in applications requiring good weldability. In contrast, steel at Y with 1.5% carbon is a high carbon steel. This type of steel is known for its hardness and ability to hold a sharp edge, making it suitable for tools and cutting applications, but it is difficult to machine.