A method for depositing metal layers in the pare-des of shells intended for continuous casting

摘要

A method of depositing a metal coating on the wall of a chill mould for use in continuous casting wherein the mould is placed in a deposition bath such that an internal wall thereof to be coated is oriented generally upright, the deposition bath being composed of a solution containing at least one nickel salt and a suspension of particles of a hard metal having a critical deposition temperature range defined by upper and lower limit temperatures. A metallic layer containing nickel is deposited on the mould wall either by electrolytic or by electroless techniques, and during such deposition the mould wall is maintained at a temperature in the vicinity of one of the upper and lower limit temperatures while the solution is maintained at a temperature in the vicinity of the other of the limit temperatures, the temperature difference between the mould wall and the solution being within the aforesaid critical deposition temperature range. During deposition, the solution is maintained in a turbulent state and is circulated at a speed in excess of the sedimentation speed of the hard material particles suspended therein and also in the opposite direction to rising and falling currents along the mould wall. Where the mould wall is made of copper and the deposition is performed by an electroless method, the mould wall can be treated by applying to it a stream of free-falling iron balls which are recirculated.