- Hardening & Tempering
- Annealing & Stress Relieving
- Decarburisation Annealing
- Solutionising & Ageing
Roller Hearth Furnaces are built in a variety of ways for different applications, depending on shape, the products to be heat treated are either directly placed on the rollers (like rods, plates, coils, discs, rings etc.) or in baskets which travel on the rollers (like small & medium parts, springs, fasteners, forgings, castings etc.)
Traditionally rollers are either heat resistant steel, wrought tubes or centricast with alloy end & shafts between 50mm & upto 200mm in diameter and dispersed at a pitch between 150mm to 600mm
A more recent innovation called close pitch roller hearth furnaces employ smaller diameter tubes typ. 20mm dia at a very close pitch, typ. 25mm dia so as to make it suitable for direct loading of smaller parts (e.g. 40mm dia bearing race). These tubes are made not only in heat resisting steel but also in ceramic materials like SiC & Al2O3 thus making these furnaces suitable for very high temperature (1400°C). These furnaces are capable for a number of applications like sintering, ceramic forging etc. for which roller hearth furnaces were not previously considered.