Prodecimiento of obtaining a phosphate coating on a piece of iron or steel and iron piece or corresponding steel.

摘要

Procedure for obtaining a phosphate coating on a piece of iron or steel and iron piece or corresponding steel.; The process according to the invention comprises a first step of coating a first phosphating, whereby a first crystalline layer of iron phosphate and manganese, an intermediate step of partial etching of said first crystalline layer of phosphates, partially leaves is obtained discovered the base metal, and a second coating step comprising a second phosphating through which a second crystalline layer of iron and manganese phosphates is obtained covering the first layer and partially etched metal. The method provides a coating thinner and finer crystallization that obtainable by phosphating a simple, resulting in a smaller thickness and a lower roughness Rk.