Replacement for Picral?
Replacement for Picral?
(OP)
Someone mentioned on a recent post that their employer does not allow them to have picric acid, and unfortunately I am in the same boat. I work in the failure lab and deal mainly with plain carbon steels. Does anyone have a good recommendation for an etchant that can act similarly to picral? I understand that their is no substitute, but I would like to experiment with alternatives if possible.





RE: Replacement for Picral?
thread330-148964: Picric Acid in the Met Lab?
http://www.leco.com/resources/application_notes/pd...
http://www.georgevandervoort.com/met_papers/Ironan...
and others
RE: Replacement for Picral?
I would thus recommend you clarifying the real dangers associated with picric acid to your employer so you can safely use picral.
Aaron Tanzer
www.lehightesting.com
RE: Replacement for Picral?
RE: Replacement for Picral?
Also consider mixing only enough Picral for each use.
RE: Replacement for Picral?
Nital is the usual etchant for carbon and alloy steels, but it is essentially limited to revealing ferrite grain boundaries and general etching of martensite. Picral attacks the interfaces between ferrite and carbides, so it is useful for etching pearlite, bainite, and other carbide-containing microstructures. It is quite useful for etching dual-phase and multiphase steels, as well as tool steels. Another good application is for resolving weld fusion in steel tubes manufactured by the ERW process.