  We model the quantum Hall effect in heterostructures made of two gapped
graphene stripes with different gaps, $\Delta_1$ and $\Delta_2$. We consider
two main situations, $\Delta_1=0,\Delta_2\neq0$ and $\Delta_1=-\Delta_2$. They
are different in a fundamental aspect: only the latter feature kink states
that, when intervalley coupling is absent, are protected against
backscattering. We compute the two terminal conductance of heterostructures
with channel length up to 430 nm, in two transport configurations, parallel and
perpendicular to the interface. By studying the effect of disorder on the
transport along the boundary, we quantify the robustness of kink states with
respect to backscattering. Transport perpendicular to the boundary shows how
interface states open a backscattering channel for the conducting edge states,
spoiling the perfect conductance quantization featured by the homogeneously
gapped graphene Hall bars. Our results can be relevant for the study of
graphene deposited on hexagonal Boron-Nitride as well as to model graphene with
an interaction-driven gapped phase with two equivalent phases separated by a
domain wall.
