Microstructure and properties following welding of duplex stainless steel using coated electrodes

The effects of he type electrode coating - basic or rutile - on the microst ructure, and strength and impact properties of ca welded structure construc ted from duplex stainless steel UNS-S31803 were investigated It was found t hat the use of a resole coated electrode leads to considerable porosity and a higher nitrogen content brat lower oxygen, and hence less epsilon -Fe2O3 is created compared with weldments produced using an electrode leaving a b asic coating. These phenomena, in turn, cause a higher volume fraction of a ustenite grad thus a higher low temperature impact energy, as well as impro ved ductility; however, the yield strength is reduced compared with that fo llowing basic coated electrode welding.