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+--- Thread: Metallurgy of Steel for Bladesmiths- Dr. Verhoeven (/showthread.php?tid=70)
RE: Metallurgy of Steel for Bladesmiths- Dr. Verhoeven - Rupert Lucius - 01-13-2018
https://www.youtube.com/watch?v=Q-ooSWhFszc
RE: Metallurgy of Steel for Bladesmiths- Dr. Verhoeven - Rupert Lucius - 01-13-2018
(01-13-2018, 10:50 PM)Rupert Lucius Wrote: http://www.youtube.com/watch?v=Q-ooSWhFszc
https://www.youtube.com/watch?v=aWENpliHWLg
Two knife smiths. Mr. Ed for sure is proud of his student Mark and their accomplishments with 52100.
Rupert
RE: Metallurgy of Steel for Bladesmiths- Dr. Verhoeven - Rupert Lucius - 01-14-2018
(01-13-2018, 10:59 PM)Rupert Lucius Wrote:(01-13-2018, 10:50 PM)Rupert Lucius Wrote: http://www.youtube.com/watch?v=Q-ooSWhFszc
https://www.youtube.com/watch?v=aWENpliHWLg
Two knife smiths. Mr. Ed for sure is proud of his student Mark and their accomplishments with 52100.
Rupert
https://www.youtube.com/watch?v=9VjtYfoVTeQ
RE: Metallurgy of Steel for Bladesmiths- Dr. Verhoeven - Mark Reich - 01-14-2018
WOW!
I was really fat and out of shape.
RE: Metallurgy of Steel for Bladesmiths- Dr. Verhoeven - Jan - 01-15-2018
(01-13-2018, 10:59 PM)Rupert Lucius Wrote:(01-13-2018, 10:50 PM)Rupert Lucius Wrote: http://www.youtube.com/watch?v=Q-ooSWhFszc
https://www.youtube.com/watch?v=aWENpliHWLg
Two knife smiths. Mr. Ed for sure is proud of his student Mark and their accomplishments with 52100.
Rupert
I am always glad to see a blacksmith forging. Especially when it is Mr. Mark! Forging is closely tight with the cultural history of man. Probably the Sumerians living in Mesopotamia about 4500 B.C. were the founders of metallurgy as we understand it today.
[attachment=427] [attachment=428]
The Romans even had gods dedicated to the forge, one of them was Vulcan.
[attachment=429]
Metallurgist’s corner: the attached page explains what happens in the tortured blade during the 90 degrees flexing. The failure is not explained, may be it is too complicated.
[attachment=416]
Jan
RE: Metallurgy of Steel for Bladesmiths- Dr. Verhoeven - Mark Reich - 01-16-2018
This is snipped out of another thread, because I was going way off topic there, and this is a more appropriate thread.
Just because I've never heard of something means very little, and you are able to come up with all sorts of things I haven't heard of, so I appreciate your contributions.
Here is yet another example;
(Quote) "Annealed steel has a much higher carbide volume fraction than hardened steel..." (Unquote)
What is "carbide volume fraction", and what sort of properties do these carbides have vs. carbides in hardened steel?
Do these carbides have the same composition/hardness? Are they larger and fewer, or opposite?
Since it seems I hear things like, "carbides do the cutting", I'm hoping you know if/where carbide development is explained by Dr. Verhoeven, or is it too complicated to be described simply?
RE: Metallurgy of Steel for Bladesmiths- Dr. Verhoeven - me2 - 01-16-2018
Carbide volume fraction is a way to measure how much carbide is in a steel. So if you have 100 cubic inches of steel and a volume fraction of 5%, then 5 cubic inches is carbide all mixed up in little tiny bits.
These carbides are the same as those in hardened steel. This is where the phase diagrams come in handy. In a simple steel like 1095, the carbide is Fe3C, iron carbide, or cementite, all are the same. It is present at room temperature in annealed 1095 steel, at about 15% volume fraction. When heated for hardening, it will typically have 2% to 5% volume fraction. These are the same carbides as at room temperature, and when quenched they are still the same. The phase diagram can be used to calculate volume fraction. Carbides can be bigger or smaller, it depends on temperatures used.
RE: Metallurgy of Steel for Bladesmiths- Dr. Verhoeven - me2 - 01-16-2018
I'm unfamiliar with the notion that carbides do the cutting. It is fairly well recognized that a fine knife or other cutting tool can be made of steels with no or very few carbides in the hardened condition, such as 5160, 1084, 1075, 15N20, etc. Is this more in reference to carbide tipped cutting bits? The topic is in Verhoeven's book. It's in the section on austenization. I think he dedicates a full chapter to that topic. This chapter again points to the value of the phase diagrams as a starting point. I keep mentioning that, as I feel I emphasized their limitations more than I should have.
RE: Metallurgy of Steel for Bladesmiths- Dr. Verhoeven - Jan - 01-17-2018
(01-16-2018, 11:04 AM)me2 Wrote: Carbide volume fraction is a way to measure how much carbide is in a steel. So if you have 100 cubic inches of steel and a volume fraction of 5%, then 5 cubic inches is carbide all mixed up in little tiny bits.
These carbides are the same as those in hardened steel. This is where the phase diagrams come in handy. In a simple steel like 1095, the carbide is Fe3C, iron carbide, or cementite, all are the same. It is present at room temperature in annealed 1095 steel, at about 15% volume fraction. When heated for hardening, it will typically have 2% to 5% volume fraction. These are the same carbides as at room temperature, and when quenched they are still the same. The phase diagram can be used to calculate volume fraction. Carbides can be bigger or smaller, it depends on temperatures used.
Me2, I am wondering why the quantity "carbide volume fraction" is used in metallurgy.
All iron – carbon phase diagrams use mass (weight) % of Carbon. To calculate the "carbide volume fraction" we would need to know the densities of both phases under consideration. Do we know the densities reliably? Even more densities slightly depend on temperature.
In my understanding mass (weight) fraction is good not only for carbon but also for carbide and numerically both measures are almost identical.
Jan
RE: Metallurgy of Steel for Bladesmiths- Dr. Verhoeven - me2 - 01-17-2018
In the case of steels, yes the densities are very close and the weight fraction is approximately the same as the volume fraction. Volume fraction is used when actual measurements are made from micrographs, and estimates from the Fe-C diagram are expressed the same. For other systems, one has to be more careful. When digging into bronzes a while ago, l didn't get deep enough to get into this. It's discussed more more for steels, add carbide volume is closely tied to wear resistance and toughness.