Consider the following statements regarding annealing process:
1. All structural imperfections are removed
2. The hypoeutectoid steel is heated to about 50 – 70°C below upper critical temperature
3. Cooling can be done in heat treating furnace, by heating it, keeping the metal in it and turning off furnace till it cools to room temperature
4. Uniform grain structure is resulted Which of these statements are correct?
(a) 1, 2 and 3 only (b) 2, 3 and 4 only
(c) 1, 3 and 4 only (d) 1, 2, 3 and 4