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Why do chrome plated piston rodshave pinholes?
Nov 03, 2018

During the chrome plating process of the chrome-plated piston rod, some small pinholes sometimes appear on the surface of the plating. The so-called pinhole is a tiny hole from the surface of the plating layer to the underlying cover layer or the base metal. It is mostly caused by the gas (hydrogen) staying on the surface of the plated part. Pinholes may also be caused by pits on the base metal. Therefore, the cause of pinholes is more complicated.


First of all, it may be due to the uneven distribution of metallographic structure in the chrome-plated piston rod base material, or it may be due to insufficient internal stress relief. These parts are not plated with chromium during plating to form pinholes. Such pinholes have a cracked coating and the distribution of pinholes is often irregular. The oil on the surface of the plated parts is not thoroughly cleaned. The place where there is oil in the plating is not conductive or the conductivity is poor. At these parts, the gas easily stays and pinholes are generated. The pinholes formed by this factor are locally dense and irregular.


The car is caused by severe rust on the surface of the chrome-plated piston rod before it is plated, so that when the plating is performed, the rust is not electrically conductive, resulting in pinholes. In addition, the surface of the chrome-plated piston rod is rough or scratched, and pinholes are easily generated.http://www.xhychromerod.com/