TWR2;
SA 217 WC6 is weldable with E8018 B2. I would suggest that if your repairs are considered minor (not structural) and are under 1/2" nominal deposit thickness, and if you don't have time and what you state is accurate regarding service use, you can use the following suggestion for weld repair to this casting, at your own risk;
1. Apply a local preheat of 400 deg F.
2. Use 3/32" E8018 B2 (low hydrogen) weld electrodes (SMAW process) and deposit 2 passes over the entire excavation surface and extend 3/16" on to the original surface of the casting surrounding the excavation.
3. After the first two passes have been deposited, switch to a 1/8" diameter electrode, E8018 B2 (low hydrogen) and finish filling the excavation while remaining on top of the first two passes.
4. Add one additional pass after the excavation has been completely filled again while remaining on top of the original 2 passes, which will be subsequently ground off to make the weld repair region substantially flush with surrounding base material.
5. Perform a final wet fluorescent MT or liquid penetrant inspection of the weld repair region.