Methods and electrolyte compositions for electrodepositing metal-carbon alloys

Methods for electrodepositing a metal-carbon coating on a substrate comprising immersing the substrate in an aqueous electrolyte, and passing a sufficient current through the electrolyte to effect electrolyte deposition of a metal-carbon alloy on the substrate. The aqueous electrolyte comprises from about 0.2 to about 0.6 mol/l of metal ions selected from the group consisting of iron, nickel, nickel-tungsten mixture and cobalt-tungsten mixture, greater than about 1.4 mol/l of an amidosulfonic acid or a salt thereof, ammonium ions, formic acid or a salt thereof, and water.