Techincal Numismatics - Pitting Corrosion, Hydrogen Embrittlement, and Residual Stress Cracking
Rittenhouse
Posts: 565 ✭✭✭
For those who are techie nerds like JD and I, we have an article out in the current Gobrecht Journal on Pitting Corrosion, Hydrogen Embrittlement, and Residual Stress Cracking which will provide some of the how and why of cracks & pits on coining dies. A slightly revised version will be published in the John Reich Journal for the early crowd.
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Comments
Cool! Looking forward to reading it with JRCS.
Lance.
For those who are not LSCC or JRCS, I will post links to versions on my DropBox after both GJ and JRJ have been out for a while.
That should be an interesting article!
I have always been fascinated by various aspects of metallurgy. Look forward to the article. Cheers, RickO
Look forward to the links.
Thank you for doing this. Look forward to it.
"Hydrogen embrittlement" will be of particular interest since there was no general source of hydrogen (atomic or molecular) until methane came into general use for heating planchets and die steel.
It's rather obvious you have no idea of what hydrogen embrittlement is, how it occurs, or how hydrogen is generated, and probably to whom you speak.
@Rittenhouse said:
Why the nasty post?
Why yours?
???? Could we please use civil discourse to further our discussions and provide useful information to the forum?
Thank you, Cheers, RickO
“Rittenhouse:” My earlier post was simply an expression of interest, nothing more.
Just finished the article...interesting to say the least. Really nice macro images, and that 1850-O 50C Liberty needs to see a dermatologist ASAP before it spreads more!
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THen I apologize. I took it as a backhanded criticism casting doubt on an article you hadn't even read.
Glad you liked it. There are other dies that's show a bit more pitting corrosion. We chose that one for the photo angle and lack of heavy toning.
Finding photos to clearly illustrate these micro die features is tough. Easy to see "coin-in-hand," but quite difficult to find a photo that accurately communicates to the reader.
Hydrogen embrittlement has plagued steel processing since the days of the Romans. The problem was described but not understood. When you are dealing with earth wind fire water, it is a bit tough to understand. The problem was also documented but not understood with Damascus Steel, specifically in sabers and swords. All of this was long before 1776
Hard to analyse the problem when hydrogen had not been "discovered" yet.
We dealt with hydrogen embrittlement in plating processes years ago when I worked in the printed circuit industry... could cause a lot of scrap. Cheers, RickO