Duplex SS like 2205 , UNS31803 etc are not advised to be repair welded on weld. And the common engineering prescription is fully cut out the entire weldment and do a fresh new weld. It has been urgumented that repair welding in duplex is not encouraged to avoid additional heat input which can have effect to the formation of detrimental brittle phases like sigma, chi that is harmful w.r.t. mechanical performance of the item. Q1. If for small area LOCAL repair welding by low heat input process like TIG , the overall structure can act as a heat sink the effect of additional heat input can have more degree of disscipation. Is there any experience that anyone has done local area duplex repair ( if so what are the total repair % area w.r.t. entire weld/ Parent Metal ) without any history of failure due to local sigma phase formation ? Q2. Any other incidence/ experience any one would like to share please. regards