Engineering Materials
In a hardening process, the hypo-eutectoid steel is_____.
- A. Heated from 30°C to 50°C above the upper critical temperature and then cooled in still air
- B. Heated from 30°C to 50°C above the upper critical temperature and then cooled suddenly in a suitable cooling medium
- C. Heated from 30°C to 50°C above the upper critical temperature and then cooled slowly in the furnace
- D. Heated below or closes to the lower critical temperature and then cooled slowly