Welding of Hyper-Duplex Stainless Steels

Duplex stainless steels are materials based on the Fe-Cr-Ni-N alloy system, where the chemical composition has been adjusted such that the steel’s base metal microstructure consists of nominally 50% ferrite and 50% austenite, hence the term duplex. Because of the higher alloy contents and demanding processing, the duplex stainless steels are more costly to produce than the austenitic alloys. Hyper Duplex Stainless Steels (HDSS) produced by ESAB/ EXATON are materials with a remarkable yield strength (≥700 MPa) and corrosion resistance, which have been develop as an alternative to super-duplex stainless steels, where higher mechanical and corrosion performance is required or desirable. However, such highly alloyed materials are quite prone to intermetallic phase formation. For this specific application, tubesheets made of HDSS are not available and therefore, HDSS-cladded carbon steels plates are used. A better understanding of HDSS cladding operations and its effect on the intermetallic phases precipitation, corrosion and impact toughness performance is needed.

Industry Sponsor: ESAB, Petrobras

Faculty: Antonio Ramirez (OSU)

Graduate Student: Andres Acuna

Industry Contact: Ravi Menon, Leo Paixao