A compound tube comprises a layer of a Fe--Cr--Al-alloy and a layer of a load-carrying component and optionally one or several additional layers. The Fe--Cr--Al-alloy has the following analysis in weight-%: carbon<0.3, chromium 5-30, nickel<10, manganese<5, molybdenum<5, aluminium 3-20 , silicon<5, nitrogen<0.3, cerium+bafnium+yttrium<1.0, titanium 0.005-1.0, zirconium 0.005-1.0, niobium 0.005-1.0, the remainder iron, and naturally occurring impurities. These tubes are very resistant towards carbonization and "metal dusting" and are being used to advantage for bayonet tubing, superheat tubing and reformer tubing in steam formation.

Un tube composé comporte une couche d'un Fe -- Cr -- Al-alliage et une couche d'un composant supportant la charge et sur option d'une ou plusieurs couches additionnelles. Le Fe -- Cr -- l'Al-alliage a l'analyse suivante dans le poids-% : carbone