Annealing of steel is the process of heating steel

Options

A. to bright red hot and then cooling it slowly
B. to bright red hot and then cooling it suddenly
C. to temperature much below redness and cooling it slowly
D. none of the above

Answer

**Step-by-Step Solution:**

1. **Understanding Annealing**: Annealing is a heat treatment process used to alter the physical and sometimes chemical properties of a material. In the case of steel, it involves heating the steel to a specific temperature and then allowing it to cool slowly.

2. **Heating Steel**: The steel is heated to a temperature where it becomes bright red hot. This temperature is typically around 700 to 800 degrees Celsius, depending on the type of steel.

3. **Cooling Process**: After reaching the desired temperature, the steel is allowed to cool slowly. This slow cooling process helps to relieve internal stresses, improve ductility, and refine the grain structure of the steel.

4. **Identifying the Correct Option**: Given the options (A, B, C, D), we need to identify which one correctly describes the annealing process.
- Option A states that annealing is the process of heating steel to bright red hot and then cooling it slowly. This matches the definition of annealing.
- Option B describes hardening, which involves heating and then cooling suddenly.
- Option C describes tempering, which involves heating below redness and then cooling slowly.
- Option D does not accurately describe annealing.

5. **Conclusion**: Based on the definitions and processes described, we can conclude that the correct answer is Option A.

**Final Answer**: Option A is correct.

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