Selective removal of nickel-based alloys from ferrous-based metals

摘要

Nickel-based alloys can be removed from ferrous-based metals without damaging the ferrous-based metal by a process comprising immersing the nickel-based alloy/ferrous-based metal composite into an electrolyte solution which will not attack the ferrous-based metal at a specified voltage condition. This voltage condition is imposed across the composite and potentiostatically controlled to produce a nickel-alloy/ferrous-metal current density ratio in the composite which results in etching of the nickel-based alloy with no damage to the ferrous-based metal. The process has particular utility for removing nickel-based alloy brazed vanes from stainless steel shrouds in gas turbine engine stators.