|
Post by pvsampson on Jun 2, 2019 5:27:54 GMT
|
|
|
Post by bradc on Jun 2, 2019 6:09:15 GMT
Thanks for those links! I saw this link in another thread around here recently and found it to have some really great summaries of crystal structures, dislocations, and the effects of forging vs transition temperatures (mainly sections 5 and 8). So far a great read. The author does a pretty commendable job writing everything in a relatively approachable manner given the complexity of the topic. www.tf.uni-kiel.de/matwis/amat/iss/index.html
|
|
|
Post by michael1969 on Jun 2, 2019 8:45:24 GMT
As a former knife maker I can answer that one. Most definately yes, steel benefits from being forged over stock removal when it comes to blades. Forging actually aligns the grain structure of the steel, compacts the grain so to speak. The result is a much more durable, tougher steel. The amou of forging shown in the video on the 1045 carbon blanks isnt much, but yes that steel is going to benefit from what little forging it recieved. Not as much obviously as a blade forged totally by hand or power hammer. So hammering the steel makes it tougher? As far as I have learned hammering is used to shape and originally removed the impurities,and with modern steels there is no need to hammer at all.Plenty of knife and swordmakers use stock removal only,and then the heat treatment dictates how tough the steel is for example normalizing before heat and quench.Heating the steel above critical temperature changes the crystalline structure and then the cooling process dictates the grain size,as in annealing and normalizing. Normalizing creates uniformity in the grain structure to provide stress relief. If a stock removal 9260 blade has a 52 Rockwell hardness and uniform grain structure,and a hammered 9260 blade of same dimensions has the same hardness and structure,then which one is tougher? First let me say a better term would be forging makes the steel stronger. To answer your question, forging simply makes the grain structure even more uniform. A properly forged blade of any type of steel will always out perform a stock removal blade made from the same steel. Yes, you are correct about heat treating, annealing, and normalizing refining the crystalline size...but forging actually aligns and compacts the grain structure, stock removal can never do that. Heat treating and thermal cycles further refine grain structure and go on to actually make the crystalline size smaller. A good visual for the mind is compare a pine 2x4 to say an oak 2x4...the oak is much stronger because the grain of the wood is much more dense and compact and very straight. Pine has a very open and loose grain structure. Forging will align and compact the grain of the steel giving you a stronger blade over a stock removal blade.
|
|
|
Post by pvsampson on Jun 2, 2019 9:25:49 GMT
So hammering the steel makes it tougher? As far as I have learned hammering is used to shape and originally removed the impurities,and with modern steels there is no need to hammer at all.Plenty of knife and swordmakers use stock removal only,and then the heat treatment dictates how tough the steel is for example normalizing before heat and quench.Heating the steel above critical temperature changes the crystalline structure and then the cooling process dictates the grain size,as in annealing and normalizing. Normalizing creates uniformity in the grain structure to provide stress relief. If a stock removal 9260 blade has a 52 Rockwell hardness and uniform grain structure,and a hammered 9260 blade of same dimensions has the same hardness and structure,then which one is tougher? First let me say a better term would be forging makes the steel stronger. To answer your question, forging simply makes the grain structure even more uniform. A properly forged blade of any type of steel will always out perform a stock removal blade made from the same steel. Yes, you are correct about heat treating, annealing, and normalizing refining the crystalline size...but forging actually aligns and compacts the grain structure, stock removal can never do that. Heat treating and thermal cycles further refine grain structure and go on to actually make the crystalline size smaller. A good visual for the mind is compare a pine 2x4 to say an oak 2x4...the oak is much stronger because the grain of the wood is much more dense and compact and very straight. Pine has a very open and loose grain structure. Forging will align and compact the grain of the steel giving you a stronger blade over a stock removal blade. How does forging make the steel stronger? How does it align and compact the "grain" structure?
|
|
|
Post by AndiTheBarvarian on Jun 2, 2019 9:30:38 GMT
www.cashenblades.com/images/articles/lowdown.html It does and then the heat treating kills the whole effect again. And stock removal blades are usually made out of rolled steel which already has been "forged" due to the rolling process. To stay with the wood example: Heat treating makes both pieces of wood to compressed wood with much finer and compact grain than even oak had before.
|
|
|
Post by michael1969 on Jun 2, 2019 14:15:55 GMT
www.cashenblades.com/images/articles/lowdown.html It does and then the heat treating kills the whole effect again. And stock removal blades are usually made out of rolled steel which already has been "forged" due to the rolling process. To stay with the wood example: Heat treating makes both pieces of wood to compressed wood with much finer and compact grain than even oak had before. Heat treating does not kill the whole effect, heat treating further refines it by improving (shrinking) the crystalline structure of the steel. You can improve the steel even further by putting it through what is called thermal cycles. This involves heating the steel to a non-magnetic state, also called critical or the same state at which quenching is done at...then allow the steel to air cool until it becomes magnetic again, then repeat by heating to non-magnetic and allowing to air cool again. This can be repeated for several cycles to further improve the steel. Many believe that just heat treating the steel is what gives it the Rockwell hardness, that is not true. The hardness comes from the quench and then the tempering of the steel. The quench will almost always make the blade too hard. Tempering the blade involves reheating to a much lower temperature, holding it at that temperature and allowing it to "soak". This will draw the hardness back to a more useable state amd give a blade it edge retention and flexibility. Different steels benefit from different heat treat, quench, and tempering temperatures. 1095 steel is a notoriously difficult steel to heat treat than say 5160.
|
|
|
Post by michael1969 on Jun 2, 2019 15:28:38 GMT
They are all a pretty penny tho? No? The model I went with currently starts at 1600. It's easy to go up several hundred from there with aesthetic upgrades, so yeah a couple really pretty pennies... My willpower almost faded at their folded carbon blade (3k starting) the pictures were very promising (choji hamon with lots of ashi).... Congrats on the new purchase, please let us know what you think of it when it arrives. I'm contemplating very hard on a Motohara.
|
|
|
Post by pvsampson on Jun 3, 2019 2:34:53 GMT
www.cashenblades.com/images/articles/lowdown.html It does and then the heat treating kills the whole effect again. And stock removal blades are usually made out of rolled steel which already has been "forged" due to the rolling process. To stay with the wood example: Heat treating makes both pieces of wood to compressed wood with much finer and compact grain than even oak had before. Yeah I understand the process. The reason I was questioning is so that the poster can provide evidence of his claims.He stated that "forging" makes the steel stronger, hence a heated and hammered blade is stronger. That is just rubbish. There is no actual evidence for this claim,and the processes described in the latter post are just normalizing and final heat treat/quench and tempering. Those are the processes that determine the final strength of the steel. Not heating and hammering.A stock removal blade that has been normalized,then heat/quenched and tempered is just as strong as a blade that has been heated,hammered,normalized etc. A heated and hammered blade is in no way better than a stock removal blade,properly heat treated.
|
|
|
Post by AndiTheBarvarian on Jun 3, 2019 3:46:39 GMT
|
|
|
Post by bradc on Jun 3, 2019 4:09:58 GMT
The model I went with currently starts at 1600. It's easy to go up several hundred from there with aesthetic upgrades, so yeah a couple really pretty pennies... My willpower almost faded at their folded carbon blade (3k starting) the pictures were very promising (choji hamon with lots of ashi).... Congrats on the new purchase, please let us know what you think of it when it arrives. I'm contemplating very hard on a Motohara. Will do. I'm just impatiently waiting over here (I'm glad this is only expected to be ~8 weeks from ordering I dont know how people handle the multi year waits for some forges)
|
|
|
Post by bradc on Jun 3, 2019 4:31:17 GMT
www.cashenblades.com/images/articles/lowdown.html It does and then the heat treating kills the whole effect again. And stock removal blades are usually made out of rolled steel which already has been "forged" due to the rolling process. To stay with the wood example: Heat treating makes both pieces of wood to compressed wood with much finer and compact grain than even oak had before. Heat treating does not kill the whole effect, heat treating further refines it by improving (shrinking) the crystalline structure of the steel. You can improve the steel even further by putting it through what is called thermal cycles. This involves heating the steel to a non-magnetic state, also called critical or the same state at which quenching is done at...then allow the steel to air cool until it becomes magnetic again, then repeat by heating to non-magnetic and allowing to air cool again. This can be repeated for several cycles to further improve the steel. Many believe that just heat treating the steel is what gives it the Rockwell hardness, that is not true. The hardness comes from the quench and then the tempering of the steel. The quench will almost always make the blade too hard. Tempering the blade involves reheating to a much lower temperature, holding it at that temperature and allowing it to "soak". This will draw the hardness back to a more useable state amd give a blade it edge retention and flexibility. Different steels benefit from different heat treat, quench, and tempering temperatures. 1095 steel is a notoriously difficult steel to heat treat than say 5160. Ok I'm very much still learning here (not a materials engineer and realizing steel is crazy complicated stuff). So from my recent (aka today.) reading I was under the impression that hammering the steel after heating past the austentite transformation temperature (~1000 K) or heating past that point after hammering would undo most of the structures induced by forging before that point. So do you only heat to non magnetic before final hammering? Is time at temperature really important? Or is the loss of structure before the Curie temperature way more complex than this over simplification? Am I just getting way over my head and confused (FYI Here's the specific source I was reading. Section 8.2 of www.tf.uni-kiel.de/matwis/amat/iss/index.html )
|
|
|
Post by michael1969 on Jun 3, 2019 5:45:20 GMT
The link didnt work for me. Said "not found"...its been a lot of years since I was in the forging game, I struggle to explain things sometimes, there is a documentary on YouTube about Wootz steel that gives better explanations than I can. Its a very interesting documentary that has experts in metallurgy explaining thermal cycles etc. Sorry if I have caused more confusion than anything.
|
|
|
Post by bradc on Jun 3, 2019 5:58:08 GMT
The link didnt work for me. Said "not found"...its been a lot of years since I was in the forging game, I struggle to explain things sometimes, there is a documentary on YouTube about Wootz steel that gives better explanations than I can. Its a very interesting documentary that has experts in metallurgy explaining thermal cycles etc. Sorry if I have caused more confusion than anything. No worries, I'm just working my way down the rabbit hole of steel crystal structures and getting myself thoroughly confused plenty on my own ... Fixed the link (It seems you can't deep link into the page). The wootz documentary looks interesting. Queued up for later. Thanks!
|
|
|
Post by Silent on Jun 3, 2019 11:16:31 GMT
I think you guys are living in a old age. Modern steel doesnt need forging, unless it was produced by some homesmelter?
Modern monosteel like 1084 comes "pure" ready to simply quench right away if you want to... Obviously grinding on it, creates stress that will need extra care/normalizations before quench not to get broken/bent quenched blade.
Meaning, forging does improve steels that have lots of impurities in it, but these normally don't. A lot of swordsmiths, start with bars and simply forge down the side bevels.
|
|
|
Post by bradc on Jul 15, 2019 4:45:15 GMT
Not quite in hand yet. But Evolution Blades posted pics of my finished custom L6 Motohara on their Facebook page. Since my eventual photos won't be as good I'll share the link to theirs / So far looks great, and I am excited to be receiving it soon. Will update after I have received and had a chance to practice with it a bit. Edit can't seem to get Facebook links to just display the direct link in this forum. I'll see if I can figure out how to get that to display as just a direct text link to the post instead of this preview box.
|
|
|
Post by skane on Jul 16, 2019 1:49:17 GMT
Edit can't seem to get Facebook links to just display the direct link in this forum. I'll see if I can figure out how to get that to display as just a direct text link to the post instead of this preview box. Here's a link to your sword on the EB page - Motohara L6
|
|
|
Post by kami on Nov 3, 2023 19:42:32 GMT
If he isn't a collector or backyard cutter.. What is he then? Nothing encourages focus like a 3ft razor... Gold 🤣
|
|