  Energy cascade rates and Kolmogorov's constant for nonhelical steady
magnetohydrodynamic turbulence have been calculated by solving the flux
equations to the first order in perturbation. For zero cross helicity and space
dimension $d=3$, magnetic energy cascades from large length-scales to small
length-scales (forward cascade). In addition, there are energy fluxes from
large-scale magnetic field to small-scale velocity field, large-scale velocity
field to small-scale magnetic field, and large-scale velocity field to
large-scale magnetic field. Kolmogorov's constant for magnetohydrodynamics is
approximately equal to that for fluid turbulence ($\approx 1.6$) for Alfv\'{e}n
ratio $0.5 \le r_A \le \infty$. For higher space-dimensions, the energy fluxes
are qualitatively similar, and Kolmogorov's constant varies as $d^{1/3}$. For
the normalized cross helicity $\sigma_c \to 1$, the cascade rates are
proportional to $(1-\sigma_c)/ (1+\sigma_c)$, and the Kolmogorov's constants
vary significantly with $\sigma_c$.
