A zinc-coated steel may be produced by performing a pre-alloying heat treatment after galvannealing the steel and prior to the hot stamping the steel. The pre-alloying heat treatment is conducted at a temperature between about 850° F. and about 950° F. in an open coil annealing process. The pre-alloying heat treatment allows for shorter time at the austenitization temperature to form a desired α-Fe phase in the coating by increasing the concentration of iron. This also decreases the loss of zinc, and a more adherent oxide exists after hot stamping.