01-13-2015, 03:06 AM
Bryan wrote:
" Meanwhile, those iron blades that were case hardened on the edges, or pattern welded, or made with quality iron, and then heat treated, could be made to be flexible (as stated by Philon)."
no, they could not. physics of the construction stand against that. if you have, for example, a simple soft steel core with welded-on high carbon cutting edges which are properly hardened and tempered, the whole weapon will stay bent after a wrong hit. the edges alone would be flexible, but the soft, ductile core will not allow that. the same about pattern welded cores containing mostly soft steel and a grain structure destroyed or interrupted by the grinding of the blade.
to get a flexible blade you have to use a single bar of steel with the right carbon content and forge the blade out of this piece, then harden and quench it.
the main reason for the use of high carbon steel just on the edges of a blade is simply money: it`s expensive in time, manpower and resources to make steel (mainly by carburisation )
This is a little too vague to say yes or no on. First off Bryan said case hardening not butt welding edges to an iron core. There is a difference. case hardening is the adding of carbon to the whole exterior of a blade while the interior (possibly 1 - 5 mm inside) remains low in carbon. This is quite efficient on blades in particular because they are so thin and wide, therefore more surface area. YES this will give a blade springyness and it will create a quality weapon, assuming it was done properly with enough penetration of carbon.
Many methods of case hardening are also pretty simple and easy. low carbon steel or iron is sealed in a (ceramic probably) box with charcoal and heated up to high temperatures for a few hours, Done. Or thin folded (not yet welded!) Iron is brought up to welding temperatures (bright orange) and held there for around 30 minutes will pick up a few points of a percent of carbon. Both are tested using actually smelted iron and work quite well.
Also in most cases having steel edges will give some springyness to a blade. Again this depends on how much of the edge is steel and how high in carbon. It is totally possible for this to be plausible but, not always. It will guarantee a better cutting edge though.
When folks talk about the structure of steel and iron there are a few misconceptions going around id like to fix here. All of these swords are starting out as blooms from a smelting stack. This means they are folded (between a few times, to many dozens) to become a much more homogenous and silicate free piece of iron. If people are concerned of welds being exposed or that pattern welding/twisting or anything of the like having some effect on the structure for better or worse you are mistaken. when a weld is properly set it is set. potentially it can be a weak spot and weld flaws can grow BUT there are already many folds and welds going into even single bar swords. An experienced smith will not see problems where he has welded as far as delamination goes.
Doing tests on "welded steel" is not the same as historical steel. It is close but to differentiate modern welded steels from "modern mono steels" is calling the kettle black in my opinion. Without actually taking real historical smelted bloomery iron and steels, forging them and testing heat treatments, flexibility, edge retention etc there is no proper data collected. The chemical composition of modern steels welded or not are NOT THE SAME AS HISTORICAL STEELS.
Also there is this crazy idea that steel is "so laborious, time consuming and difficult to make." Where did this assumption come from? is it just assumed because steel is better than iron therefore more refined therefore harder to make. It is taking one more step in iron production but it is also simple and fast.
Heres a quick rundown of the most common ancient way to make steel documented by Aristotle!
Iron pieces (probably rods) go into a small hearth burning charcoal and fed by oxygen from the side. The iron goes into a semi-liquid (not melting) transition and gains carbon as it conglomerated at the bottom of the hearth. The steel is taken out and can be compacted a bit then forged into whatever is needed.
I have personally done this many times and made swords, of decent quality, but i dont think the romans grasped this on the chemical level we do and is therefore part of why this was not super common. It is evident that they did as time went on naturally.
Also this whole process takes about 30 minutes. Any one of you could do this in your backyard.
Ill even post a nice little video that shows steel being made then spark tested using only historical technology! :lol:
My friend and fellow bladesmith zeb demming doing what he does best.
https://www.youtube.com/watch?v=hHRyZESkMzA
So I apologize if I sound arrogant in any of my ramblings (not my intention). I like to read more than post but today I have information to share from experience and research on this subject. I have made reproductions of roman blades using ONLY bloomery steel and iron made exactly as the Romans did and tested their rigidity and found it to be very different from modern steels but still quite efficient in its own right. To be honest I am really just excited and am so glad to see this thread where people are looking so deeply into the making of roman swords. This does not get brought up enough so keep it rolling! everyones opinions and ideas are great.
" Meanwhile, those iron blades that were case hardened on the edges, or pattern welded, or made with quality iron, and then heat treated, could be made to be flexible (as stated by Philon)."
no, they could not. physics of the construction stand against that. if you have, for example, a simple soft steel core with welded-on high carbon cutting edges which are properly hardened and tempered, the whole weapon will stay bent after a wrong hit. the edges alone would be flexible, but the soft, ductile core will not allow that. the same about pattern welded cores containing mostly soft steel and a grain structure destroyed or interrupted by the grinding of the blade.
to get a flexible blade you have to use a single bar of steel with the right carbon content and forge the blade out of this piece, then harden and quench it.
the main reason for the use of high carbon steel just on the edges of a blade is simply money: it`s expensive in time, manpower and resources to make steel (mainly by carburisation )
This is a little too vague to say yes or no on. First off Bryan said case hardening not butt welding edges to an iron core. There is a difference. case hardening is the adding of carbon to the whole exterior of a blade while the interior (possibly 1 - 5 mm inside) remains low in carbon. This is quite efficient on blades in particular because they are so thin and wide, therefore more surface area. YES this will give a blade springyness and it will create a quality weapon, assuming it was done properly with enough penetration of carbon.
Many methods of case hardening are also pretty simple and easy. low carbon steel or iron is sealed in a (ceramic probably) box with charcoal and heated up to high temperatures for a few hours, Done. Or thin folded (not yet welded!) Iron is brought up to welding temperatures (bright orange) and held there for around 30 minutes will pick up a few points of a percent of carbon. Both are tested using actually smelted iron and work quite well.
Also in most cases having steel edges will give some springyness to a blade. Again this depends on how much of the edge is steel and how high in carbon. It is totally possible for this to be plausible but, not always. It will guarantee a better cutting edge though.
When folks talk about the structure of steel and iron there are a few misconceptions going around id like to fix here. All of these swords are starting out as blooms from a smelting stack. This means they are folded (between a few times, to many dozens) to become a much more homogenous and silicate free piece of iron. If people are concerned of welds being exposed or that pattern welding/twisting or anything of the like having some effect on the structure for better or worse you are mistaken. when a weld is properly set it is set. potentially it can be a weak spot and weld flaws can grow BUT there are already many folds and welds going into even single bar swords. An experienced smith will not see problems where he has welded as far as delamination goes.
Doing tests on "welded steel" is not the same as historical steel. It is close but to differentiate modern welded steels from "modern mono steels" is calling the kettle black in my opinion. Without actually taking real historical smelted bloomery iron and steels, forging them and testing heat treatments, flexibility, edge retention etc there is no proper data collected. The chemical composition of modern steels welded or not are NOT THE SAME AS HISTORICAL STEELS.
Also there is this crazy idea that steel is "so laborious, time consuming and difficult to make." Where did this assumption come from? is it just assumed because steel is better than iron therefore more refined therefore harder to make. It is taking one more step in iron production but it is also simple and fast.
Heres a quick rundown of the most common ancient way to make steel documented by Aristotle!
Iron pieces (probably rods) go into a small hearth burning charcoal and fed by oxygen from the side. The iron goes into a semi-liquid (not melting) transition and gains carbon as it conglomerated at the bottom of the hearth. The steel is taken out and can be compacted a bit then forged into whatever is needed.
I have personally done this many times and made swords, of decent quality, but i dont think the romans grasped this on the chemical level we do and is therefore part of why this was not super common. It is evident that they did as time went on naturally.
Also this whole process takes about 30 minutes. Any one of you could do this in your backyard.
Ill even post a nice little video that shows steel being made then spark tested using only historical technology! :lol:
My friend and fellow bladesmith zeb demming doing what he does best.
https://www.youtube.com/watch?v=hHRyZESkMzA
So I apologize if I sound arrogant in any of my ramblings (not my intention). I like to read more than post but today I have information to share from experience and research on this subject. I have made reproductions of roman blades using ONLY bloomery steel and iron made exactly as the Romans did and tested their rigidity and found it to be very different from modern steels but still quite efficient in its own right. To be honest I am really just excited and am so glad to see this thread where people are looking so deeply into the making of roman swords. This does not get brought up enough so keep it rolling! everyones opinions and ideas are great.
Underhill Edge
Hand forged edged tools, blades, and functioning historical reproductions.
underhilledge.com
Jack McAuliffe
Hand forged edged tools, blades, and functioning historical reproductions.
underhilledge.com
Jack McAuliffe
