If it was a single point boring head, you'd be running it at approx 50 rpm. Power required, which you can translate to a rough force estimate would be 0.0207 KW.
Sure you wouldn't rather use carbide cutters? Should be pretty easy to figure some lathe inserts that can be installed on the swing out cutters. That would make your rpm more like 400 and the power required is now 0.1775 KW per cutter.
For 3 cutters instead of a single point, the rpm will be the same. Power will be a little less than 3x, but assume 3x for the sake of conservatism. You'll want to consider how the 3 cutters will interact too:
Are they all cutting along the same annulus, with each one cutting deeper like an endmill? Are they staggered along the bore with each a different depth?
My rpm and power computations were done on G-Wizard and assumed an 0.1 mm depth of cut.
Cheers,
BW
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