Daniel Cauble

He mentioned the test end was 5x5 microns with a 1g charge. The left side was a pearlite and ferrite strike with the indention being 15% larger and the centered hits are smaller, being cementite or iron carbide.

It was really bizarre to see and try to decipher. Skip messaged me and said ledeburite, and my hunt for knowledge took off. I delved into my microscopy book and many items online. Found a lot of good information, and even stumbled across a bit of research that connected me with an archaeologist in Europe who happened to have already been following my work on IG, lol. Thanks Jerrod, I meant to make that clear.

You are welcome Jerrod. I knew I was pushing into crazy territory, but didnt fully understand cast characteristics until most recently, and what to look for in my product. As stated earlier in this or my crucible thread, I had various samples of my crucible steel and some hearth steel for a researcher to look at. On of the samples was a 4fold piece of hearth steel. He had mentioned then that I had a clean band of heavy cementite, or iron carbide in the piece. At the time it was a mystery, but now things are getting so clear. This is why I love metallurgy and steel creation. Theres so much I learn the further I go in my journey that I am able to critically inspect previous work and findings a refine my understanding. Anyway, the piece was cool and he did take a micrograph, albeit not as bright as mine are. He also used a Vickers hardness test that the microscope was outfitted with to determine between ferrite and cementite structures. Inside that dark band it was showing all of or most of the white to be cementite at the grain boundaries.

This will make things clearer .

I've hit above 4%, lol. Some of that ledeburite pics show carbon in the 3.8-4% range. I've also managed to make some gray cast with precipitated graphite. However, it doesnt play nice so its avoided.

And some crazy widmenstatten structures that are probably widmenstatten ferrite, but based on my sparks on some of it, I swear its widmenstatten cementite.

I've been talking with several archaeologists and even Skip William's (which reminds me that I need to get back in touch with him) about these structures. At any rate, I've gotten better at polishing for pics. Heres some more of steel under 2% C but right at it. Super nice stuff. This material is going into my nihonto projects and kitchen knives. What you see is saturated pearlite with grain boundary cementite. Once the steel is eutectoid, perlite can no longer store cementite.

It's an obsession I've fine tuned for over 6 years now. I've started micrographing my steel from the raw hearth steel. My results compliment findings in historically produced steels found by archaeologists which is neat. I am currently poised to be assisting in creating a large database of structures for other researchers to use. Lately I have pushed my furnace to cross the 2% C threshold and making larger quantities of white cast to be mixed and blended into my steel. Once carbon starts to cross 2%, ledeburite starts to form and the material starts to become a ceramic.

400x + camera optical zoom. Nital 3.6% (my exact concentration), 12 second etch. Getting better!!

That would be great. As much info as I can get. I currently have the book "Optical Microscopy of Carbon Steels" by L.E. Samuels, for reference. I will also try a shorter etch this next time to see if it helps.

Thank you Jerrod. I am not classically trained in microscopy so it's a learning curve. Looking at yours and looking at mine, I would say mine looks almost over etched. Idk. My left eyepiece has a faint scale bar across the middle but I never use it to take pictures because it has a crack in it. I also remembered I have .25 micron diamond paste.

WOW! 10%?? Does this enhance grain boundaries? I cannot get them to show in this folded orishigane for me. My Nital is more like 3.5%. This time I lightly knocked off the oxides with 12k grit paper, etched for 25 seconds, knocked off oxides, reached for 25, etc for about 4 goes. Enhances the sharpness a little bit, but no hope of etching deeper into the boundaries. Sigh 400x

I just made my own Nital with 68% Nitric and Methanol. yikes! Will do.

Some micrographs of the core steel. The core steel is again W2 sandwiched between orishigane. A few show the clean weld of the two disimilar metals. I need to obtain a few more etchants to show grain boundaries.

Picral, and then another that I dont have a name for that is a mixture of ethenol, picral, nitric and HCL. The picral will help bring out cementite and leave ferrite alone. The other mixture should show grain boundaries.