48609

Parameters for anodic etching [England] 

April 24, 2008

Can anyone suggest a common set of parameters for anodic etching of steel parts.
We use a 35-40% solution of Sulphuric acid, connect the parts to the anode and set 20 ASF for 5 minutes. Then 200 ASF for 1 minute, followed by a cathodic etch at 200 ASF for 3-4 seconds.
Is this similar to what others are doing, and is the cathodic etch necessary, and if so, why?

Michael Channing
Senior Chemist - Hampshire, England

Mike,

Have a lookat DEF STAN 03-2, it describes various anodic and cathodic etches, their usees and restrictions. If nothing else it will give you a starting point. You could also have a look at MIL-S-5002, the US equivalent spec.

Brian Terry
Aerospace - Yeovil, Somerset, UK