  We investigate the superconducting phase in the K(x)Ba(1-x)Fe2As2 122
compounds from moderate to strong hole-doping regimes. Using functional
renormalization group, we show that while the system develops a nodeless
anisotropic s+- order parameter in the moderately doped regime, gapping out the
electron pockets at strong hole doping drives the system into a nodal cos (kx)
cos (ky) d-wave superconducting state. This is in agreement with recent
experimental evidence from measurements on KFe2As2 which see a nodal order
parameter in the extreme doping regime. The magnetic instability is strongly
suppressed. The case of only hole pockets present is argued to be structurally
similar to the case of only electron pockets present as indicated for KxFe2Se2.
