Calorizing treatment is the surface modification method that diffuses aluminum (Al) into a metal surface to form an aluminum diffusion layer.
This treatment has the characteristics of high-temperature oxidation resistance,carburization resistance, high-temperature sulfidation resistance, etc., and exerts superior effects.
The surface of Calorizing treated metal has a Fe-Al alloy layer with high-Al-concentration. When the Fe-Al alloy layer is exposed to high-temperature oxidation atmosphere, Al is selectively oxidized and the coating film of Al2O3 is formed on the outermost surface.
This coating film can prevent oxidation to a material by protecting base material from oxygen permeation.
| Material： | SS400、Calorized SS400 | ||
|---|---|---|---|
| Conditions： | atmosphere | ||
| Time： | 1,000 Hr. | ||
| Result： |
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| Calorized steel can endure high-temperature oxidation semipermanently as long as the temperature is kept under 900℃. |
Calorizing treatment has the great effect in extending product life. Because Calorizing can prevent carburization, and so prevents cracking and distortion of the product.
| Material： | SCH13、Calorized SCH13 |
|---|---|
| Conditions： | solid carburizing |
| Time： | heating at 930°C × 12 Hr. 10 charge |
Calorizing treatment has the extremely high resistance to sulfidation corrosion caused by crude oil.
Furthermore, it has the effect of preventing stress corrosion cracking of austenitic stainless steel by polythionic acid occurred in hydrodesulfurization device.
| Material | Corrosion amount(mg/cm2) | Ratio(times) | |
|---|---|---|---|
| Untreated | Calorizing | ||
| Carbon steel | 173.5 | 0.6 | 290 |
| 2%Cr-0.5Mo-Steel | 124.0 | 0.5 | 248 |
| 5%Cr-0.5Mo-Steel | 172.8 | 1.3 | 133 |
| SUS304 | 36.5 | 0.1 | 365 |
Austenitic stainless steel with Calorizing treatment has the great effect in resistance for stress corrosion cracking.
Austenitic stainless steel with Calorizing treatment has the great effect in resistance for nitridization resistance.
Calorizing treatment has the great effect in hard to be eroded from molten zinc, molten cast iron, molten pig iron, molten copper, etc.
Calorizing treatment has the excellent durability for seawater, ammonia water, CaCl2solution, salt solution, carbonated water, acetic acid, oil, tar, asphalt, and nitric acid.
Calorizing treatment has the great effect in resistance for hydrogen permeation.
Copper with Calorizing treatment has the great effect to prevent sticking of metal spatter and welding of weld bead, or be able to remove them easily.
