The Carbide3D cutters are ZrN coated, which is primarily intended for nonferrous metals. For iron you want AlTiN, TiCN, TiN or TiAlN. Or just plain uncoated carbide.
I actually recall seeing someone who made a little dish on the bed so the part could be submerged, can’t find it right now though…
And even if flood isn’t possible, there are other ways.