verview of duplex welding 2.1 Welding metallurgy 22 2.2 Welded joints preparation 26 2.3 Thermal welding conditions 28 2.4 Welding processes 29 2.5 Ferrite determination 34 2.6 Post-fabrication clean up 36 2.7 Inspection 38 n introduction to duplex stainless steels