Calorized Layer
Calorized layer refers to an aluminum diffused layer onto the mild steel pipes when heated up to 1,000oC and forms heat resistant aluminum-iron alloys over the surface of mild steel pipes to improve its resistance to high temperatures.
The process of applying a calorized layer involves heating the metal surface to a high temperature and then diffusing the aluminum-iron alloy onto it. As the aluminum-iron alloy comes into contact with the hot metal surface, it melts and fuses with the surface, creating an aluminum oxide (alumina) film over the surface and protects mid steel pipes against severe oxidation.
