How to deal with blackening when using diaphragm coupling?

Diaphragm coupling in the process of use sometimes there will be a black situation at this time how should we deal with it? Presumably this is a more confused problem with many operators, then let the coupling manufacturer to explain to you the reason for the black.



How to deal with blackening when using diaphragm coupling?

When these blackening situations occur, it is necessary to play a series of anti-rust effects on the surface of the entire fastener, to increase the smoothness of the surface during the entire treatment process and to improve their aesthetics in this way, which can also effectively reduce the stress effect during the quenching process.
When the whole diaphragm coupling is used in the liquid, it may cause a series of corrosion to some acidic objects and have a certain dissolution effect on the metal, and of course, it may also have a variety of different displacement reactions to some other ions when it is used.
In this case, some of the original particles can be replaced by each other and deposited on the surface of the metal, and the solution itself has some oxidizing agents added to it so that in addition to some of the different ions in the nitrite are reduced, contributing to oxidation or other chemical reactions on the surface of the metal.