Lawrence,
E6022 used for making Puddle Welds when attaching deck to the supporting structural member(techincal term is Arc Spot Weld).(yes, 60ksi, Flat position only, burns hot and fast)
There is no prep, just burn through the decking and make a nugget of 3/8" min or whatever the WPS calls for.
To test, you make a puddle with a min of 1/32" reinforcement, hit the piece of deck with a hammer on the side to torsionally twist the decking off and inspect the resulting nugget.