I guess that lands in metal finishing though what I am looking for is not your typical finish.

I grabbed up a few pieces of round bar while out picking a farmer's boneyard the other day--stuff that I am fairly sure is wrought (haven't cleaned it our done any cut tests yet).  Wrought is fairly uncommon around here because we don't have a lot of stuff that is pre about 1890, and the vast majority is post 1910.  But with searching, there is some in the boneyards of most of the really early farms.

In any case, what I want to do is etch a piece to really show the grain--emphasize what wrought looks like.  I will also be doing a cut and bend piece to show what that looks like.  This is for the museum display in our forging area, the intent being to try and show people including the local farmers with boneyards what to keep an eye out for and NOT simply haul off with the rest of their scrap.  The nature of the weather here is similar to the desert in that we don't get a lot of corrosion that would cause the grain structure to show and if the piece is buried, it tends to be protected by our soils rather than corroding:  Wrought isn't easy to spot among the 10,000 tons of plain old steel scrap.

So, is there a recommended etchant or process to bring out the grain better than another?  Something that would tend to make it really kick visually?  Some way to make the grain/ fibrous nature really stand out?

Thanks

Muriatic acid or Ferric Chloride will do it

Diluted FC or hot white vinegar. 

I'd go with muriatic to get a deep etch fairly fast and cheaply.

Thanks, all.   I do have both muriatic and FC in my arsenal but wasn't sure if there was another better option to get a really deep etch.  

Etching WI is trial and error, due to the many variations and qualities around. Try first with a slow less aggressive acid. You must clean the surface from all oxides first. If it is not satisfactory try different acid. 

I etched a steeled wrought iron adze for way to long once in vinegar, (over a week), no topography, just a colour difference between the WI and Steel.