  Collective flows of protons and deuterons for Au + Au collisions at beam
energy $E_{beam}$ = 1.23 $A$ GeV were simulated by an Isospin dependent Quantum
Molecular Dynamics (IQMD) model. Two coalescence models, namely naive
coalescence and dynamical coalescence models, for the formation of deuterons
are compared. After reasonable match of rapidity spectra of protons and
deuterons to the High Acceptance DiElectron Spectrometer (HADES) data is
reached, we apply an event-plane method to calculate the first four-order
collective flow coefficients as well as the ratios of $<v_4>/<v_2>^2$ and
$<v_3>/<v_1><v_2>$, and observe the number of constituent nucleon scaling among
protons and deuterons. In addition, the dependence of $\epsilon_n$ and $v_n$ as
well as the ratio $<v_n>$/$\epsilon_n$ on the centrality is obtained. Lastly,
we further investigate the Pearson coefficients $corr(v_n,v_m)$ between the
first four harmonic flows for protons and deuterons as a function of rapidity
and centrality.
