It is done on regular basis. Shops have weld procedures to do this on pressure vessels and piping. The requirements for pwht will vary depending on which code, sizes, thickness, etc. If this is on code equipment or piping, then you will likely need to document WPS, qualify PQR and qualify your welder WPQ.
The weld wire can be one of several choices - it can be carbon steel or it can be low alloy. It depends on specific application, service temperature, stress, etc. For example;
SFA 5.18 ER70S-2 through 6
or (lower temperature service, and the strength matches the P1 base metal strength)
SFA 5.28 ER80S-B2 (higher temperature service, and the strength and corrosion resistance are a match to P4 base material) or even ER80S-D2 or E90S-D2 (where you have even higher strength).
