T23: purging required?
T23: purging required?
(OP)
I am preparing some welding procedures for T23 tubes (7 to 15mm thick). This grade is a first time for us, although we have welded low-alloy grades before (91 and 92).
Is back-purging required for root runs in T23? I have found publications that recommend purging root runs for any low-alloy grade with Cr>2%, other for Cr>3%. The material we are weldign has approx 2.3% Cr.
Is back-purging required for root runs in T23? I have found publications that recommend purging root runs for any low-alloy grade with Cr>2%, other for Cr>3%. The material we are weldign has approx 2.3% Cr.





RE: T23: purging required?
RE: T23: purging required?
Back to the EPRI document, there is specific reference to recommending the use of a purge for the lower chromium CSEF steel grades to reduce oxidation and to promote increased fusion. The purge can be Argon-grade gas and it is recommended to hold the purge until the root and hot passes have been completed.
I just wanted to be sure I gave you current and reliable advice.
RE: T23: purging required?
The welds are being made for R&D purposes, so I will purge as I would not like root defects to influence the test results.