[Picture Hvy] Some of my Orishigane for Japanese Blades.

[Daniel Cauble 66]

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.

 

Edited August 23 by Daniel Cauble

[Daniel Cauble 66]

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

[Alan Longmire 1,687]

Good for you, dude!  You're getting above 2% in a hearth?  

[Daniel Cauble 66]

17 minutes ago, Alan Longmire said:

Good for you, dude!  You're getting above 2% in a hearth?  

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.

 

 

[Daniel Cauble 66]

This will make things clearer .

[Jerrod Miller 292]

That is a fun phase diagram.  Thanks for sharing.  

[Alan Longmire 1,687]

Indeed it is!  Right on the edge of my understanding, too!    I've never looked at diagrams for cast iron, so a lot of that is new to me.  

[Daniel Cauble 66]

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.

Edited August 23 by Daniel Cauble

[Jerrod Miller 292]

I would like to point out for those that don't know, these are the indentations from the Vicker's hardness test.  This is a very small (localized) hardness check. 

 

[Daniel Cauble 66]

26 minutes ago, Alan Longmire said:

Indeed it is!  Right on the edge of my understanding, too!    I've never looked at diagrams for cast iron, so a lot of that is new to me.  

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.

[Daniel Cauble 66]

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.

Edited August 23 by Daniel Cauble