Duplex Stainless Steels
Austenitic/ferritic steels with 35-75%Fe, 22-25.5% Cr, 5-6.5%Ni, and 3% Mo
Used in chemical plant/pipelines
Welded with special rods - higher nickel to stabilise austenite and ensure correct composition for best corrosion resistance (50/50 ???)
- Avoid low heat input welding
- Control maximum interpass temperature
Can be susceptible to hot cracking