Welding T23 to P91 Utilizing NBIC WM6

[powerplantcwi]

I have a boiler repair that will consist of replacing a section of 2"OD x .201"MW T23 tube with a section of T91 tube. There is a T23/T91 dissimilar weld line just below the repair area and there is no T23 tube stock on-hand but have the T91. I am planning to utilize the NBIC weld method 6 for the T91/T91 weld line and am curious if I can use it for the dissimilar weld as well using the ER80SB8 filler, in place of the recommended CR2WV filler, with the same results to eliminate the need for PWHT of the dissimilar weld in a boiler internal setting. I am aware that I will have to run a separate PQR but would like to know if anyone has done this.

 

[davefitz]

I am not sure, but if that tube is used as a waterwall tube then you would need to be aware that there had been significant cracking issues in europe when T23 was used in waterwall service- I recall that a special PWHT is required to avoid hydrogen cracking.

"...when logic, and proportion, have fallen, sloppy dead..." Grace Slick

 

Is this material selection being driven by material availability (or lack thereof)?

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[powerplantcwi]

The tube are located in the secondary superheater panels of the boiler hanging the top of the furnace. and we are haveing trouble finding the T23 material.