At the reformer bottom header which had cracks due to creep at the header to header welds. The base material Incoloy 800H has a better creep condition compared to the welds which had been welded with Inconel 82. My plan is to repair the welds by using better creep resistance filler wire. My selection is Inconel 617filler wire. What is the expected problems during the welding and service of Incoloy 800H welded with Inconel 617 at 33bar pressure and 980C. Do you have better suggestion on the filler material selection? Cem Dericioglu Inspection & Welding Engineer

CEM Incoloy 800 H welding. Inco 82 filler wire has limitations of creep for 100,000 hrs for used Inco Alloy 800 H repairs. You could think of Inco 92 or Inco 625 filer wire both have higher creep strength even at 800 deg cent. Inco 92 may give problems of additions of Ti in ageing. Inco 625 may be Ok. It is worth first run with Inco 82 followed by Inco 92 / Inco 625 if you wish to continue with TIG welding throughout. If you wish to try inco 92 or Inco 625 filler wire and then try Inco Weld A- Electrode then you will get better creep rupture properties for the same used Inco Alloy 800 H reformer header pigtail or hair pin tubes welding or between header to pigtail or hair pin tubes weld. These do develop creep fissures after some years depending on the temperature of oepration of reformer tubes. These are weldable even if there are creep fissures provided you take care in evaluation and do welding carefully. Service life can be improved with such repair welding - provided the inital Inco Alloy 800 H had not seen service life less than 30-000-50,000 hrs and had been operated mostly below design conditions except for occasional abuse of over-run temperature. if the history of operation had shown that there have been temperature excesses in reformer tubes, then repair welding of hair prin tubes with excessive creep fissures or creep-rupture cracks - even though this material is quite ductile - will give rise to welding problems. Trust this answers your querry C.V.Srinivasan Nishi Engineers Pvt Ltd Chennai India March 01,2005 E-mail: nishi@vsnl.com, nishi@hathway.com March 01, 2005 11.20 hrsIndian time >CEM: > >We know of others that have used 617 filler to weld alloy >800 when increased creep strength is needed. The only >problem we can personally advise of is possible poor >weldability if the alloy 800 contains creep voids. > >Hope this helps! > > >David Hendrix >The Hendrix Group Inc.