  Chemical cartography of the Galactic disk provides insights to its structure
and assembly history over cosmic time. In this work, we use chemical
cartography to explore chemical gradients and azimuthal substructure in the
Milky Way disk with giant stars from APOGEE DR17. We confirm the existence of a
radial metallicity gradient in the disk of $\Delta$[Fe/H]/$\Delta$R $\sim
-0.066 \pm 0.0004$ dex/kpc and a vertical metallicity gradient of
$\Delta$[Fe/H]/$\Delta$Z $\sim -0.164 \pm 0.001$ dex/kpc. We find azimuthal
variations ($\pm0.1$ dex) on top of the radial metallicity gradient that have
been previously established with other surveys. The APOGEE giants show strong
correlations with stellar age and the intensity of azimuthal variations in
iron; older stellar populations show the largest deviations from the radial
metallicity gradient. Beyond iron, we show that other elements (e.g., Mg, O)
display azimuthal variations at the $\pm0.05$ dex-level across the Galactic
disk. We illustrate that moving into the orbit-space could help constrain the
mechanisms producing these azimuthal metallicity variations. These results
suggest that the spiral arms of the Galaxy are not solely responsible for
azimuthal metallicity variations and other Galactic processes are at play.
