Weldind 410SS (F6) to P91/F91

Date 10-05-2002 01:57

Use the Inconel Alloy 82 filler metal or 182 electrodes. These are designated ERNiCr-3 for the bare wire or ENiCrFe-3 for SMAW electrodes. You will need to apply a surfacing or "buttering" weld to the P91 side of the joint, perform the postweld heat treatment, then join the 410 SS to the Inconel buttering. You might try the Bohler-Thyssen website for some good technical info on welding the P91 alloy or Special Metals for info on the Inconel welding electrodes.

http://www.btwusa.com/library/

http://www.specialmetals.com/publication/tech_bulletin_welding.pdf

Marty

By GRoberts (***)

Date 10-07-2002 15:06

Both P91 and 410 can be PWHT in the same temperature range. So you can use mathching filler metal for either base metal and be ok. (AWS A5.5 PWHT for 9015-B9 is 1375F, and A5.4 for 410 is 1350 to 1400F). The weld metal is squarely in the M or M + F region of the Schaffler diagram, so you don't really have to worry about forming a brittle grain stucture in the weld metal (avoiding the A+M+F region). I am currently qualifying a 410 to 5 Cr procedure and am using 410NiMo (mostly because the MIL spec allows a lower preheat with this filler)