New generation ferritic and duplex stainless steels: Preliminary study on mechanical and in-service properties of welded joints

This pre-screening study covers two novel ferritic and one duplex stainless steel: the 17% Cr - double Nb+Ti stabilised 1.4509 and 1.4521, the latter with additional 2% Mo alloying, and the so-called "lean duplex" grade 1.4162 with 21.5% Cr - 5% Mn - 1.5% Ni - N. The materials were used as 2 mm. Welded joints were fabricated using resistance spot (RSW), gas metal arc (GMAW) and laser welding (LBW). The joints were subjected to tensile and microhardness testing, as well as microstructural analysis. Critical pitting temperature (CPT) corrosion tests were performed on both the base materials and welded joints. The weld microhardness tests did not reveal any significant softening effect due to welding operations. Comprehensive CPT data were achieved for all the base materials and their welds. Microstructural cha-racterisation revealed that retaining the desired ferrite-austenite balance in duplex laser beam welds still remains a challenge