Process and apparatus for producing a blackening or bluing oxide layer on the surface of iron-containing parts produced by powder metallurgy

摘要

A process and an apparatus for producing a blackening or bluing oxide layer on the surface of iron-containing parts produced by powder metallurgy are described. The parts are treated in a reaction chamber with an oxidising atmosphere at temperatures above 300 DEG C. This oxidising atmosphere is prepared from fuels burned sub-stoichiometrically at an apparent reaction temperature of T 800 DEG C, and the combustion products are discharged from the combustion point directly into the reaction chamber. The apparatus is characterised in that it is designed as a continuous furnace and has at least one combustion chamber which is arranged within the furnace chamber or extends into the latter and which has an upstream mixing device, by means of which a fuel/air mixture can be fed to the combustion chamber. IMAGE