00:06 Mar-23-2010 Stan NDT Inspector, Canada, Joined Jan 2009 31
Etching for Penetrant
I hope that someone can offer some advice here.
What is an appropriate etching technique, etchant and times, for carbon steel items that may have been peened over, to open any surface flaws to allow a Penetrant Examination.
The items that I am dealing with are specimens with known flaws that are going to be used for training and testing purposes. At present, the known flaws show only marginal detectability using typical penetrant techniques, and I am hoping to increase the detectability of these flaws by etching the surface.
Any other suggestions would be welcomed.
You could dip the part in muratic acid (available at any local hardware store) for just a second, then rinse and dry the part. Perform liquid penetrant testing, if the results are not satisfactory, repeat the process with a little longer time in the acid. It may be time consuming, but it should work.