U and W shaped radiant tubes for tube temperatures up to 1250°C (2280°F). The radiant tubes includes nickel-chromium (NrCr) alloys or iron-chromium-aluminium (FeCrAl) alloys for extremely demanding environments, of combinations of the two material types.

  High-temperature corrosion properties

Material	In Air / Oxidizing	Oxidizing Sulphur	Reducing Sulphur	Carburizing	Nitriding
ASTM 310	0	0	0	0	0
253 MA1)	+	+	++	+	02)
353 MA1)	+	-	0	++	++
SD Consults APM	++	++	++++	+++	+3)
SD Consults APMT	++	++	++++	+++	+3)

•   253 MA and 353 MA are trademarks owned by Outokumpu OY
•   Nitriding may occur at very low dew point (<-60°C/-51°F)
•   Severe nitriding may occur at low dew point (<-20°C/-29°F)

 

 

 

Oxidation properties at 1100ºC (2040ºF)	Carburization rate for various alloys

  Radiant tubes for tougher conditions at the burner leg
In some furnaces not all parts of a radiant tube is exposed to extreme temperatures. In these cases, an alternative is to use Kanthal APM or Kanthal APMT iron-nickel-chromium (FeCrAl) alloy for the burner leg and a nickel-chromium (NiCr) alloy for the bend and the return tube.