Waste heat boilers
The Sandvik program includes composite tubes for use in waste heat boilers in metallurgical plants.
Composite tubes with Sandvik 3R12 (ASTM TP304L) outer layer provide excellent protection against flue gas (for example SO2) corrosion. Sanicro® 28 (UNS N08028) is an even better oxide former and used for more severe conditions. The inner component, Sandvik 4L7 (ASME SA201-A1, P265GH), is a well-proven low-alloy steel, in principle immune to water/steam side induced stress corrosion cracking (SCC).