Temper bead welding has been used for many years, mainly in cases where repairs were necessary after PWHT had already been done. When properly implemented it may be used in lieu of PWHT.
Temper bead welding is pretty involved and until this past edition of ASME IX really had no rules except within implementing codes (mainly ASME Section III, nuclear work).
The one thing lacking in the 2004 edition is a WPS/PQR format to record all of the variables. I believe the subcommittee's are looking into this in order to develop a suggested format.
For a wealth of information and background on temperbead welding go to www.sperkoengineering.com
See if this link will open: https://www.aws.org/w/s/process
The above was an article published by Mr. Sperko in a recent issue of the Welding Journal.