Focus will be extremely important in the equation but here you go anyways:
Power: 4000
Initial Frequency: 10
Initial Duty: 15
Gas Pressure: .05 MPA (.5 kg or bar)
Nozzle Gap: .059
Incremental Freq: 10
Incremental Duty: 1
Step Time: .5 seconds
Pierce Time: 15 seconds
Use a 2.5 WACS Double Nozzle or the equivalent. You may have to massage the piercing parameters a bit, maybe increase the initial duty cycles to 20 but decrease the gas pressure to 0.04 MPA. Use pierce 101 and focus should be around 0.080" or 2 mm positive above material surface.
Good Luck