  In this paper, we obtain the global-in-$x$ Sobolev stability of Prandtl layer
expansions for 2-D steady incompressible MHD flows with shear outer ideal MHD
flows $(1,0,\sigma,0)$ ($\sigma\geq 0$) on a moving plate. It is worth noticing
that in the Sobolev sense, the degeneracy of the tangential magnetic field in
our result is allowed, which is much different from both the unsteady case in
[25,26,27] and the steady case in [3,4].
