Powered rollers carry the load through the furnace, so large, heavy parts and long stock such as pipe, tube, strip and slabs can be treated in high volume. Smaller parts travel in trays or baskets.
For controlled-atmosphere work the furnace has an entry lock, heated chamber, holding and slow-cooling zones, rapid cooling and, if needed, an exit lock. Heating is electric or by gas-fired radiant tubes. Cooling can be by air, water circulation or fast atmosphere recirculation, with rapid, uniform quenching to keep distortion low.
Specifications
| Temperature range | Up to 1150 °C |
|---|---|
| Insulation | Vacuum-formed ceramic fibre board, ceramic fibre blanket and module, or refractory brick lining |
| Heating | Electric or gas-fired radiant tube |
| Heating elements | Nichrome, special alloy wire or silicon carbide rods |
| Furnace class | Class 2 or Class 3 |
| Controls | Thyristor power control, programmable temperature controller, recorder, PLC, SCADA or HMI |
Applications
- Hardening, carburizing, carbonitriding, case hardening
- Annealing, including soft annealing of tool and bearing steels
- Normalizing, tempering, stress relieving, ageing
- Brazing and sintering
Advantages
- Low operating cost and long component life
- Easy, safe and repeatable operation
- Easy access for maintenance
- Improves wear resistance and limits deformation on gears and shafts
- Full anneal of steel castings for better machinability
Common questions
What is a roller hearth furnace?
A versatile design mostly used to index baskets of parts forward. It can also oscillate for long heating cycles on very long stock.