use of ER 80S B2 in welding p22 material

By TimGary (****)

Date 05-01-2024 11:44

This forum has been around for so long that just about any welding related google search shows past conversations from this forum, such as this one-
https://app.aws.org/forum/topic_show.pl?tid=12504

If you use the search function for further research, you'll find more info than you need from the 20 year + post archives.

Tim

By Jovi Zhu (**)

Date 05-05-2024 01:42

As Tim already pointed out via the existing posts, B2 is designed for P11/12 and correct/typical filler metal for P22 should be B3.

However when welding dissimilar grades such as between P22 and and lower grade (P11/12 or even Carbon steel), B2 is used as a good "in-between" becuase the weld joint only have to be strong than the weaker side.

The minimum specifed tensile strength of ER 80S-B2 is still higher than that of the P22. You can even try to qualify a WPS using B2 between P22. From this point of view the joint will not have too high chance for an immediate failure and can even easily pass a hydro-test.

From a long term it depends on the service condition. Such as when creep strength, corrosion resistence, etc. are considered, the B2 weld metal will not be of matching chemical composition to provided desired properties.

By pradeep4u (*)

Date 05-11-2024 10:52

Thanks all for your valuable inputs. Now if 90 S -B3 used for P11 materials then because of different chemistry of weld material and parent metal can any failure occurs in near or long term. Thanks in advance
Regads
A.Pradeep

By Jovi Zhu (**)

Date 05-13-2024 06:05

B3 is of the matching chemical composition of Gr.22, when joining P22 and P11 both B2 and B3 are used by manufacturers.

However, if B3 is used for P11 to P11 especially when heavy thickness, make sure the WPS PWHT is qualified because most Codes and standards give PWHT requirement based on base metal other than weld metal. PWHT for Gr.22 should be considered for B3 weld metal. Othewise the lower PWHT temperture for P11 may not be sufficient then there is chance to produce a brittle weld that can fail in short term.

If proper PWHT is done, there should not be big concern for short term failure. For long term consideration it will depend on the service conditions under which such mismatch will lead to any potential failure.