Posted by TVP on July 24, 2008 at 12:49:28:
In Reply to: Etching for grain size in 430 stainless steel posted by Robert M. Entler on July 24, 2008 at 07:35:21:
Robert, I posted a response to a similar question very recently. Here is an excerpt:
There are a number of etchants that can be used for ferritic stainless steels, such as Vilella's reagent, Ralph's reagent, and glyceregia, but for revealing the grain boundaries in high purity, low interstitial alloys like E-Brite, the best etchant is electrolytic nitric acid (60 mL HNO3 + 40 mL H2O), 1.2-1.5 V dc for ~ 120 s. ASM HANDBOOK Volume 9 even shows two excellent image of E-Brite, one etched with acetic glyceregia and the other with electrolytic HNO3. I encourage you to obtain this authoritative reference book if you don't already have it.