CromElso® 91 is an alloyed martensitic CrMoVNb steel designed for high temperature creep resistance up to 600°C (1100°F). CromElso® 91 is manufactured via the electric furnace with dephosphorisation, ladle refining and vacuum degassing to provide a reproducible, clean and homogeneous steel.

The use of special steelmaking practice gives CromElso® 91 improved heat affected zone impact toughness properties. Balanced low carbon gives enhanced weldability for pipe and pressure vessel fabrication, while it is at the same time high enough to contribute to the creep resistance.

Other controlled ratios of compositional elements like nitrogen and aluminium also give rise to the better creep properties of the steel, which are basically obtained through its strong martensitic structure.

CromElso® 91 is particularly suitable for supercritical steam piping for enhanced thermodynamical efficiency in energy generation processes.

This steel is commonly available in plate form in thickness up to at least 90 mm. Very large thicknesses are also available for pressure vessel components typical of the refining and nuclear energy industries.