Understanding the four basic processes for steel
| Process | Temp | Cooling | Result |
|---|---|---|---|
| Annealing | Ac3+30-50C | Furnace cool | Softest, machinable |
| Normalizing | Ac3+50-80C | Air cool | Fine grain, uniform |
| Quenching | Ac3+30-50C | Oil/water | Hardest, brittle |
| Tempering | 150-650C | Air cool | Target hardness+toughness |
Always temper after quenching. Tempering at 200C reduces hardness 2-3 HRC but increases toughness 50-100%.