BUTTING – Duplex & superduplex

Besides austenitic steels, special alloys and titanium, BUTTING has specialised in the fabrication of duplex, superduplex and lean duplex materials. We have been supplying pipes and piping components in these materials for worldwide use since 1979. More than 130 000 tons have been processed for various projects all over the world in the petrochemical, paper and oil and gas industries, as well as for waste water treatment, chemical tanker building and seawater desalination plants.

Varieties of duplex steel are used for two main reasons: on the one hand, because of their corrosion resistance to a variety of media which exist in on-shore and off-shore areas, on the other hand for their increased strength. Typical applications are underwater manifolds and flow-lines, along with linepipes and underwater pipelines and topside processing systems.

The group of superduplex steels is even more highly alloyed than the one of duplex steels, and is also distinguished from the latter by its increased resistance to pitting, crevice and stress corrosion cracking and through an additional increase in its specific values for strength.

Austenitic-ferritic steels with a lower alloy content than standard duplex steels are grouped together in the so-called “lean duplex” group. Depending on the task to be performed, they may represent an economically interesting alternative to the standard duplex steels. Compared to standard steels like 304L and 316L, the lean duplex steels offer the benefit that their yield strengths of 430-450 MPa represent nearly double the values, and hence allow substantial savings in wall thicknesses.

BUTTING – Progress by Tradition