A selectively corrodible downhole article includes a movable cylindrical member comprising a first section and an axially separated second section, the first section comprising a first material having a first galvanic activity, the second section comprising a second material having a second galvanic activity, the first galvanic activity being greater than the second, the first section being electrically isolated from the second section; and a fixed member disposed on the cylindrical member and configured for electrical contact with the first or second section, the fixed member comprising an intermediate material having an intermediate galvanic activity, the intermediate galvanic activity being intermediate the first and second galvanic activity, the movable cylindrical member configured for movement from a first position where the first section is disposed and in electrical contact with the fixed member and a second position where the second section is disposed and in electrical contact with the fixed member.