welding of 2.25Cr-1.6W-V-Cb & 18Cr-9Ni-3Cu-Cb-N

Date 04-01-2010 12:48

The best advice would be to contact a T23 manufacturer such as V and M.
You're going to end up using a nickel base alloy to accomodate the differential in expansion coefficients of the bainitic/martensitic T23 with the austenitic alloy.
I am assuming this is for a Super critical?

By G.S.Crisi (****)

Date 04-01-2010 20:21

Curiosity: by Supercritical do you mean a supercritical boiler?
Giovanni S. Crisi
Sao Paulo - Brazil

By js55

Date 04-01-2010 20:27

yes. sorry about that.

By ssbn727 (*****)

Date 04-01-2010 22:48

Sounds like one of the huge super-critical boiler coal fired power plants being built in China... Correct??? Or are they using them for the new Nukes they're building there also???

Respectfully,
Henry

By G.S.Crisi (****)

Date 04-05-2010 23:51

Another curious question, js. Who's V and M?
Giovanni S. Crisi

By js55

Date 04-06-2010 12:23

Vallourec Mannesmann. They are leaders in the manufacture of low alloy creep enhanced ferritics.

By G.S.Crisi (****)

Date 04-06-2010 13:06

They're also in Brazil, where they make carbon steel and 0.5% molybdenum pipes and tubes.
Giovanni S. Crisi

By H. Chang (*)

Date 04-02-2010 00:56 Edited 04-02-2010 01:01

Many thanks for the prompt replies from everyone
Yes, these materials are to be used on a supercritical boiler in Japan
Sorry that I didn’t explain my question clearly in the first place
Actually, it is a butt-welded joint in between of 2.25Cr-1.6W-V-Cb tubes (Code case 2199)
And the other is a butt-welded joint in between of 18Cr-9Ni-3Cu-Cb-N (Code case 2328)
For 2.25Cr-1.6W-V-Cb tube, I will ask V&M, but I'll certainly appreciate any comments of practical welding of both of abovementioned materials.
I've read some articles that indicated that for the best result of 18Cr-9Ni-3Cu-Cb-N material, it must be solution heat treated after the final manufacturing process is done. The subject tube is 57.1mm dia. with min.wall thickness of 3.5mm, does this butt-welded joint has to be solution heat-treated?
Since I don't have Code case 2199 & 2328 on hand, and I don't know what the code case requirements about these materials. And I'll be very much appreciated that someone do have and take time to email these code cases to me to"chang@csm.com.tw", thanks
Best regards everyone
H.Chang

By G.S.Crisi (****)

Date 04-05-2010 23:58 Edited 04-06-2010 00:26

Chang,
We must agree that welding of supercritical boiler tubes is a task that involves a great deal of responsibility. Even if I had a quick answer to your question (which I don't) my first advice would be to ask the boiler manufacturer for a recommendation. He's made the boiler and he should undertake the responsibility of stating every step of its erection.
Giovanni S. Crisi

By H. Chang (*)

Date 04-09-2010 00:46

Thanks for the advice
I have both Code cases on hand now, it requires a separate welding procedure and performance qualifications be conducted in accordance with Section IX
The story is that we got an inquiry from our client and ask for us to submit a quotation of supplying the pressure parts for this field assembly boiler, since we don't have previous experience of welding these materials, that's why I bring up this subject here, and hope that someone who had the experience to weld these materials to share his precious knowledge, thanks