Kinetics of the spontaneous dissolution of copper-47.3 atom-% zinc brass with hydrogen depolarization

The solid products of the dissolution of β'-ordered brass in deaerated 2.0 M H₂SO₄ have been studied by optical and electron microscopy and X-ray diffraction. It has been found that the thickness of the zinc-leached layer as time function satisfies the Erofeev equation, a layer of variable zinc contents exists in the interphase zone: brass-pure copper and a brass of bainite structure appears at the surface of the β'-ordered brass. On the assumption that the reduction of H⁺ ions is the rate-determining step of the electrochemical process the hypothesis that the rate of dissolution of brass controls the formation and growth of metallic copper phase has been corroborated.