| Author |
Message |
|
Andrew W
Location: Florida, USA Joined: 14 Oct 2010
Posts: 79
|
 Posted: Tue 24 May, 2011 6:26 pm Post subject: |
 |
|
|
For those who are interested, some additional analysis of Ulfbehrt swords: http://gladius.revistas.csic.es/index.php/gla...le/218/222 . This article shows the range of metal qualities employed, from very excellent (in what appear to have been the original maker's swords) to poor.
|
|
  |
 |
Johan Gemvik
|
| Posted: Tue 24 May, 2011 6:26 pm Post subject: |
|
|
Dustin, note that the lower half of your quote refers to steel and that there is no mention of exactly how hard the iron can get. More than the 30% mentioned for steel, the same, or less? We have no data on that so far.
I used Swedish cold rolled steel, this has a fairly high phosphorous content and the same hardening effect apparently applies to that material as well. So the question remains, does iron cold harden to a higher degree than steel if both have phosphorous content.
"The Dwarf sees farther than the Giant when he has the giant's shoulder to mount on" -Coleridge
Last edited by Johan Gemvik on Tue 24 May, 2011 6:37 pm; edited 2 times in total
|
|
|
|
|
Johan Gemvik
|
| Posted: Tue 24 May, 2011 6:31 pm Post subject: |
|
|
| Andrew W wrote: | | For those who are interested, some additional analysis of Ulfbehrt swords: http://gladius.revistas.csic.es/index.php/gla...le/218/222 . This article shows the range of metal qualities employed, from very excellent (in what appear to have been the original maker's swords) to poor. |
Ah, the collected articles from Gladius is a defining work of Professor Alan Williams often oveshadowed by The Knight and the blast Furnace. A truly excellent read.
"The Dwarf sees farther than the Giant when he has the giant's shoulder to mount on" -Coleridge
Last edited by Johan Gemvik on Sun 29 May, 2011 2:19 pm; edited 1 time in total
|
|
|
|
|
|
Dustin R. Reagan
|
| Posted: Tue 24 May, 2011 6:33 pm Post subject: |
|
|
| Johan Gemvik wrote: | | Dustin, note that the lower half of your quote refers to steel. I used Swedish cold rolled steel, this has a fairly high phosphorous content and the same hardening applies to that material as well. |
Now the burden of proof is on you to show the chemistry of this steel. I doubt that any modern mild-steel has P to the degree necessary for work-hardening.
|
|
|
|
|
|
Dustin R. Reagan
|
| Posted: Tue 24 May, 2011 6:38 pm Post subject: |
|
|
| Johan Gemvik wrote: | Or more so, as I've at least tried to do some basic tests with a similar but readily available material.
|
I'm not sure what you are trying to say here...
| Johan Gemvik wrote: |
Something to be certain of though is that HRC 50-55 in a durable edge is not achievable with cold hammering of any ferritic material known to man but straightforward to make with high carbon steel, quenching and annealing with a red hot bar or lump. |
I'm not sure what HRC 50-55 has to do with anything, historically. The record shows that even 'high-quality' swords were often quenched but then tempered softer than this. This is even when the steel used in the sword contained enough carbon to achieve RC 50+. You'd have to show that an edge this hard was desirable, historically, for this to have any bearing on the discussion...
http://www.myArmoury.com/feature_bladehardness.html
|
|
|
|
|
Johan Gemvik
|
| Posted: Tue 24 May, 2011 6:45 pm Post subject: |
|
|
| Dustin R. Reagan wrote: | | Johan Gemvik wrote: | | Dustin, note that the lower half of your quote refers to steel. I used Swedish cold rolled steel, this has a fairly high phosphorous content and the same hardening applies to that material as well. |
Now the burden of proof is on you to show the chemistry of this steel. I doubt that any modern mild-steel has P to the degree necessary for work-hardening. |
You do know that all steel work hardens, the problem with it is often the reverse, that it gets too hard to work and you have to heat treat it to normalize it to continue. They make expensive special less hardening steels to press car parts and similar to avoid it. Have you worked cold with steel at all? I do on a regular basis. If you did, it'd be obvios it can be work hardened.
By the way, what's with your hostile attitude?
"The Dwarf sees farther than the Giant when he has the giant's shoulder to mount on" -Coleridge
|
|
|
|
|
|
Dustin R. Reagan
|
| Posted: Tue 24 May, 2011 6:54 pm Post subject: |
|
|
| Johan Gemvik wrote: |
You do know that all steel work hardens, the problem with it is often the reverse, that it gets too hard to work and you have to heat treat it to normalize it to continue. They make expensive special less hardening steels to press car parts and similar to avoid it. Have you worked cold with steel at all? I do on a regular basis. If you did, it'd be obvios it can be work hardened.
|
Yes, I know this. I do work with steel on a regular basis. My point was that I do not believe that work-hardened mild steel can tell us much about the performance of work-hardened phosphoric iron blades.
| Johan Gemvik wrote: |
By the way, what's with your hostile attitude? |
I really have no idea what you are talking about here. If you'll re-read my posts, you'll find nothing but short, concise sentences. Either stating my opinion, or asking a question. I don't believe that this indicates any sort of attitude, except maybe the desire to keep a high signal-to-noise ratio.
You should realize, it is very easy to mistake "attitude" in written communication.
|
|
|
|
|
Johan Gemvik
|
| Posted: Tue 24 May, 2011 7:06 pm Post subject: |
|
|
| Dustin R. Reagan wrote: | | Johan Gemvik wrote: | Or more so, as I've at least tried to do some basic tests with a similar but readily available material.
|
I'm not sure what you are trying to say here... |
I believe I was being quite straightforward. Simply perform your own tests with whatever material you prefer and post the results. Frankly it can't be any simpler than that. Feel free to test away.
I have in no way said I would not accept such a result should it show anything else than what mine did. Nor that the simple tests I've done are by any means scientific, merely surface inquisitive to the cold working method hinting on certain aspects and possible, dare I say plausible limitations to the technique.
| Dustin R. Reagan wrote: |
I'm not sure what HRC 50-55 has to do with anything, historically. |
It's the standard for steel/ferrous tool edge hardness, it is today and has been for a very long time. It corresponds with chinese and japanese swordmaking as well as europeean. Yes, there are plenty of examples both below and above this level, but it's a decent average to aim for and is the optimal balance between hardness and durability in standard high carbon steel.
| Dustin R. Reagan wrote: |
The record shows that even 'high-quality' swords were often quenched but then tempered softer than this. This is even when the steel used in the sword contained enough carbon to achieve RC 50+. You'd have to show that an edge this hard was desirable, historically, for this to have any bearing on the discussion...
http://www.myArmoury.com/feature_bladehardness.html |
If you read the earlier discussion you'll see me quoting Jerouens post on the other forum. Specifically the Ulfberth sword he lists.
"Early medieval period:
Ulfberht sword, Donnybrook, Dublin, Ireland, ?
Centre:
- carbon contents: 0.2%
- phosporous contents: 0.02%
- manganese contents: 0.1-1.0%
Fine grained ferrite with spheroidal pearlite
Edge:
- carbon contents: 0.3-0.4%
- phosporous contents: trace
- manganese contents: 0.1%
Quench-hardened to 520-550 HV
Notes: piled layout."
This sword is apparently quench-hardened to 520-550 HV (vickers). That equates to the HRC (rockwell) I was stating.
Also, as you can plainly see in the article you link to 4 out of 13 compared swords were harder in the edge than this.
Another thing to note is the testing method. Most methods vary about +/-5 on the Rockwell chart.
"The Dwarf sees farther than the Giant when he has the giant's shoulder to mount on" -Coleridge
Last edited by Johan Gemvik on Tue 24 May, 2011 7:13 pm; edited 1 time in total
|
|
|
|
|
|
Dustin R. Reagan
|
| Posted: Tue 24 May, 2011 7:11 pm Post subject: |
|
|
| Johan Gemvik wrote: |
Also, as you can plainly see in the article you link to there were also swords harder in the edge than this. |
Also, as you can plainly see in the article I linked to the majority of the swords were softer in the edge than this.
|
|
|
|
|
|
Dustin R. Reagan
|
| Posted: Tue 24 May, 2011 7:14 pm Post subject: |
|
|
| Johan Gemvik wrote: |
I have in no way said I would not accept such a result should it show anything else than what mine did. Nor that the simple tests I've done are by any means scientific, merely surface inquisitive to the cold working method hinting on certain aspects and possible, dare I say plausible limitations to the technique.
. |
Agreed, however one could reasonably imply that you believed that the results of your tests had some bearing on the discussion of iron-age work-hardened blades since you posted it in that context.
I apologize if I missed the point of you posting these results.
Last edited by Dustin R. Reagan on Tue 24 May, 2011 9:36 pm; edited 1 time in total
|
|
|
|
|
Johan Gemvik
|
| Posted: Tue 24 May, 2011 7:18 pm Post subject: |
|
|
| Dustin R. Reagan wrote: | | Johan Gemvik wrote: |
Also, as you can plainly see in the article you link to there were also swords harder in the edge than this. |
Also, as you can plainly see in the article I linked to the majority of the swords were softer in the edge than this. |
8 out of 13 are fully within the parameters I gave, given the hardness testing having an inherent +/-5 variation on the Rockwell scale.
Exactly how does this matter anyway, seeing as HRC 40 would also be most likely unachievable by cold working iron. If I dared to guess, I'd say it could get up to just barely making the Rockwell scale at all.
"The Dwarf sees farther than the Giant when he has the giant's shoulder to mount on" -Coleridge
|
|
|
|
|
Johan Gemvik
|
| Posted: Tue 24 May, 2011 7:21 pm Post subject: |
|
|
Sorry, you posted while I was writing.
| Dustin R. Reagan wrote: | | Johan Gemvik wrote: |
I have in no way said I would not accept such a result should it show anything else than what mine did. Nor that the simple tests I've done are by any means scientific, merely surface inquisitive to the cold working method hinting on certain aspects and possible, dare I say plausible limitations to the technique.
. |
Agreed, however one could reasonably imply that you believed that the results of your tests had some bearing on the discussion of iron-age work-hardened blades since you posted it in that context.
I'm apologize if I missed the point of you posting these results. |
No, no, I was making some point with it. And you're right, it doesn't really say anything about cold working iron.
On the other hand, I'll re-read Gladius again and perhaps Williams has something to say about it. I highly recommend it, a very good read regardless. 
"The Dwarf sees farther than the Giant when he has the giant's shoulder to mount on" -Coleridge
Last edited by Johan Gemvik on Tue 24 May, 2011 7:22 pm; edited 1 time in total
|
|
|
|
|
|
Dustin R. Reagan
|
| Posted: Tue 24 May, 2011 7:22 pm Post subject: |
|
|
| Johan Gemvik wrote: |
8 out of 13 are fully within the parameters I gave, given the hardness testing having an inherent +/-5 variation on the Rockwell scale.
|
No, 8 out of 13 are possibly within the parameters you gave, given the +/-5 RC deviation you state. However, the article does not mention +/-5 (in fact, this depends on the method you are using to measure RC), but states " There is a general understanding that Rockwell numbers will vary +/- 2 points either way as an acceptable industry standard—i.e., 50Rc can be 48 to 52 and pass general industrial inspection.".
| Johan Gemvik wrote: | | I'd say it could get up to just barely making the Rockwell scale at all. |
Yes, I believe that you are correct about this.
Last edited by Dustin R. Reagan on Tue 24 May, 2011 9:36 pm; edited 1 time in total
|
|
|
|
|
Craig Johnson
Industry Professional
|
| Posted: Tue 24 May, 2011 8:41 pm Post subject: Iron/steel |
|
|
Hi guys
A great topic, but one that can go astray and is very hard to have any sense of a general over view. As Jeroen said there are people teaching this in schools that will sometimes have either out dated info or more likely are cross extrapolating and this can lead to assumptions that are pretty far off the mark. One needs to read as much of the research and history of the research as one can to give a good foundation to build on.
A key element that needs to be part of such a discussion is to make sure we are understanding the material as we find it in the artifacts of the period. Thus to say steel or iron imho creates a false sense of the material. Think of it more like a composite material that has a variable mix. Monster cookies in a sense. The amount of an alloy is going to vary a great degree through out the piece. Not the same as a modern production steel. This changes many of the assumptions one might make about structure and hardness.
I think Jeroen and Jared covered the outline pretty well. But again a huge subject and very dependent on such things as period, material source, technology and region. There is no general concept or over arching element that can be easily sketched to give a true picture of the knowledge we do have and there is a great deal to still discover and work out. This is the biggest issue with the brief descriptions Johan sighted. These were written to give a general public audience a bit of context and was possibly not written by some one who has a breadth and depth of knowledge in the field.
In reference to the 50ish range of the Rc scale for hardness Johan stated
| Johan Gemvik wrote: |
It's the standard for steel/ferrous tool edge hardness, it is today and has been for a very long time. It corresponds with chinese and japanese swordmaking as well as europeean. Yes, there are plenty of examples both below and above this level, but it's a decent average to aim for and is the optimal balance between hardness and durability in standard high carbon steel. |
I would say 50 Rc is a bit of a false assumption here. It is only a standard in the modern sword industry due to it being hard to sell swords that are less hard as its been bandied about as an "average" for swords that has turned out to not be the case. This has been done by the industry itself and many serious scholars who where basing there research on word of mouth as opposed to actual tested data. In fact the range of hardness in any one piece from the period would range over a great part of the Rc scale and in most cases is well below the 50 mark. But again it is crucial to look at the hard research that is quantified not statements about the general case as for any length of time in the epochs we are discussing the particulars would range greatly.
Pure iron will work harden very very little. Mostly dependent on the amount of impurities in the iron. The alloys present in non pure iron would then dictate the amount of hardness one can achieve by work hardening. I do have some numbers on this some where but will have to look them up unless some one else has a sight to hand. There has been research in this area I believe by Tylcote and others.
Best
Craig
|
|
  |
|
Johan Gemvik
|
| Posted: Wed 25 May, 2011 10:45 am Post subject: |
|
|
Craig, thank you for the voice of reason.
Whether the average was 30, 40 or 50 HRC for steel edged quenched blades historically, far more, or far less, was beside the point I was making and frankly I find it has no real bearing on it. -Whether cold hammered iron can be made as hard and as durable as what did exist was the point.
I never imagined this sub-topic would be so volatile or I wouldn't have bothered to post about it. My apologies all if it derailed the thread. While that's already damage done, let me explain just a little further what I was on about.
| Johan Gemvik wrote: | | Also, as far as I've read as well as heard from others on this forum (which may be unreliable), all iron age swords found so far have at least one steel edge in them. |
What I referred to here was Celtic iron swords, and a previous thread on myArmoury.com where this was stated by someone, a thread which I can't seem to locate now at all. Which I also stated may be unreliable. (Seems it was actually a thread on swordforum, see below)
However, as steel edges on these swords go, here's a quote of Lee A Jones from the first part of The Serpent in the Sword that gets you thinking. http://www.tf.uni-kiel.de/matwis/amat/def_en/...rpent.html
"Additionally, small rods could be carburized to increase hardness by increasing carbon content. Ideally, steel (which is an alloy of iron with small amounts of carbon) would be chosen to provide hardness at the edge."
The sources listed are quite impressive, as is the work itself, though it doesn't mention technical data background. I'm sure you can all understand how one expects this to be reliable information.
Also have a look at Greg Volevachs post on swordforum:
http://www.swordforum.com/forums/showthread.p...ord-Myths.
See #3 in the list, I quote:
"Modern research has revealed that even Celtic swords from 500 BC were made of different steels welded together. Roman swords were made just like their celtic counterparts; piled construction and occasionally differentially hardened. Swords from the so called “Nydam-Ship” (3-4th century AD) were complex pattern welded blades which were found to be differentially hardened. This trend continued to 10th century, where pattern welding was abandoned and laminations were used – up to 18th century."
The sources here are even more impressive, some are the very cutting edge of historical metallugy today, though Greg doesn't say from exaclty which part of which works the statements are derived from.
Also, Professor Alan Williams says in one of these source articles that iron bloomery inherently contain some amount steel that could be separated to weld in as edges.
This means that steel in some form has been around as long as humans have processed iron from ore. It's not a matter of when it was first created but when it was found and put to use.
He also states the maximum hardness phosphor enriched wrought iron can achieve from cold hammering is fairly low, around HV 130, and that iron can never gain anything from quenching or other heat treatment.
The sources also explain that high carbon infusion, as seen in many examples where the carbon content is high in the iron, can create a thin steel surface that would mostly have rusted away on a seemingly today "pure" iron sword.
"The Dwarf sees farther than the Giant when he has the giant's shoulder to mount on" -Coleridge
|
|
|
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
|
All contents © Copyright 2003-2024 myArmoury.com — All rights reserved
Discussion forums powered by phpBB © The phpBB Group
Switch to the Basic Low-bandwidth Version of the forum
|
This is a standard topic