We can perform hardening and tempering also in pit furnaces. Steel is heated to the austenitic temperature (t.i. above 723 °C). This is followed by a cooling process in appropriate media (oil, water, air, nitrogen). Austenite transforms into martensite, in which way we achieve higher workpiece hardness and toughness. Tempering at the right temperature increases steel toughness even further, eliminating the workpiece stress and giving it the required hardness.
PIT FURNACE HARDENING, ANNEALING, NORMALIZATION, TEMPERING UNDER PROTECTIVE ATMOSPHERE (OIL, WATER, COMPRESSED AIR)
| Maximum workpiece dimensions | Maximum workpiece weight | Medium (surrounding substance) |
| φ 700 × 1300 | 500 kg | oil |
| φ 700 × 1300 | 500 kg | water |
| φ 700 × 1300 | 500 kg | air |
Advantages:
- Optimal values of the workpiece mechanical properties,
- Suitable for workpieces that are subject to torsion and dynamic stress,
- In pit furnaces we can perform hardening and tempering of larger and longer workpieces.
Applications:
- Mechanical parts for engineering,
- Drive gears (axles, shafts, connecting rods, etc.),
- Various machine parts (rolls, industrial knives, etc.).
