Started forging my own stainless damascus recently. Your first question in the video is what i wondered for many months... Thanks so much for this video
Thank you for doing that So fed up with 1095 Damascus knives, I live on the coast If I want my blade to turn into a bucket of rust on the coast, I can just buy a Walmart special Thank you for moving onto stainless!
Fascinating stuff. That 100 degree per hour annealing result is quite surprising, and something I expect a lot of knife makers will be very happy to hear. Being able to let it go overnight could be a game changer for makers wanting to work with stainless who have limited themselves to low alloy steels.
So, I watched the video and I read the book; I'm still left with a question (maybe I read it and missed it); Why anneal at all? I will admit my introduction to knifemaking came from forged in fire, and those guys are making the entire knife start to finish in 5 hours, albeit with low alloy steels. I trust your research a lot more than my own knowledge. So lets say I'm just a guy in my garage that likes to swing a hammer. I like to make useful knives, so I like AEB-L kitchen knives. I forge to shape, Normalize (though I know now not to bother with that) and then I Austenitize at 1975 for 5 minutes and quench. What properties are my knives missing by not annealing in between forging and austenitizing?
You can’t drill or bandsaw cut hardened steel. Also the heat treatment response is different without the anneal. Even normalized low alloy steel heat treats differently. Annealed steel can be controlled better in heat treatment.
Loved the class at bladeshow, great to see some of that data presented again as there were some details that had slipped past me. Thanks for all the hard work!
Outstanding information. Thank you! AEB-L will be used for my third knife. I suppose I'll have to build an oven. BTW - how ironic that UA-cam puts a Coolina knife ad during your video. From next level to the basement.
You got game ! Nice video, and good education, your math is good...I deal with stainless steel for my day job and we have a lot of high tool scrap , I've been thinking about getting into blade making, working stainless is a thing, thank you for educating everyone and spreading the art of stainless steel metallurgy
superb... great insight... Seth Burton (Cosmo on Salt Spring) forged my S90V/S35VN & S110V/S35VN (Stainless "Damascus") Ingots from which he formed my 2 favourite Custom knives... Now I know why they are so good blades
Fantastic work. Thank you. Quick nerdy question. I am halfway through the video where you talk about the difference in hardness and toughness for the slower vs faster annealing of Aeb-l. Was this a single run? Triplicate? Was there error bars? Thank you!! What's the inherent error in the equipment? At what point are small changes significant vs noise. Excellent work!! Not trying to be a jerk. Just asking questions
It would be cool to see how different toughnesses translate in real life. Is a jump of 5ft-lbs noticeable? What does that look like when prying with the tip, hammering edge into hard material, etc.
Depends on the hardness. If the steel is 5ft-lbs vs 10ft-lbs 60hrc D2.. you'll NOTICE it at finer geometries. Even crazier would be something like the same HRC D2 vs AEB-L with like 5fl-lbs vs like 35 or something.
Nice. Do you know whether the forging part (both heating and compressing) is contributing to the improvements? Or is it possible that skipping forging and just re-annealing the steel from the manufacturer would have produced the same results?
The forging dissolves carbides before the anneal and the forging action prevents excessive grain growth and grain boundary carbide. I don’t know how much benefit could be gained by re-annealing as that is a test of double annealing while this was a test of properly annealing after forging
@@KnifeSteelNerds Gotcha, thanks. Could it also be that the manufacturer simply didn't do annealing as well as they could have, and you're improving the properties of the steel by doing it properly? The reason I'm interested is that I do stock removal with Magnacut, and I have no way of knowing whether to trust the manufacturer's annealing process. Each manufacturer might be doing something different, it might change over time, etc. If heating to forging temp then re-annealing will get me both better, and more consistent results, I'd consider doing it.
Their annealing wasn’t done poorly, it’s just that our goals and equipment are different than the manufacturer. As I said in the video I think using the manufacturer condition is perfectly fine.
@@KnifeSteelNerds I didn't say they did it poorly, or intend to criticize them. I'm asking if the experiments you did actually provide any relevant data to support the claim that there is some improvement you can make to the steel through the forging process. I'm sincerely trying to understand which conclusions are supported by the data and which are not. It doesn't seem to me the data supports any statements about whether forging helps or hurts. All we know is that forging + your annealing process showed improvement. Couldn't it be that your annealing was simply better? We don't know to attribute the improvements to forging vs annealing without comparing your annealing process with and without forging. Is that an unfair or incorrect conclusion?
Have you tested the toughness of ztuff with a 900 degree temper, or doing a triple temper at more typical temp ranges of 400 to 500 degrees Larrin? just wondering if there's any way to boost it's toughness up into the 55 to 58 ft lbs range. Thanks
Thanks for this, I don’t understand the avoidance that some knife makers make towards stainless steel I understand that 1095 is easy to work with But geez This is 2024, not 1955 We have the technology to have good knives now, I don’t want to have to stick my knife in a bucket of oil every day to prevent rust (live on the coast) And I don’t want to have to sharpen my knives every time I use it It’s time to move on from 1095 and low alloy steels
thermal carbide refinement should be possible wherever dissolution temp is below melting temp of the respective steel. obviously worse for high carbon steel alloyed steel but should work for many med carbon high alloy steels -- iirc for (unspecified) Vanadium carbide temp is around 1100C, lower for Cr, higher for Tungsten. aust/quench cycling should speed it up as usual.
I think it would have been really interesting to see an ingot steel with a lot more carbide than aeb-l tested like this. I understand why you would pick aeb-l for this. I just think that would be where any bigger room for improvement would be.
Yeah, AEB-L dissolves totally very near the melting temp or before. D3 or D2 have carbides pretty much even in the crucible before it fully solidifies.. they can have huge carbides and conventional cheap D2 vs CPM-D2 is crazy tougher.
would the short temper anneal have worked better if you had used a cryo cycle beforehand? or repeated short tempers? in tempering 2/3x 1-2h is the standard, why use something else for ~temper~ anneal where the same RA->Mart->ferrite/carbide conversions are at play??
So with these high carbide content steels, does forging make powder metallurgy less relevant or does the even composition of the powder metallurgy steel still play a big part in making a better steel versus the smaller carbides that forging can kind of mimic?
Forging cannot reduce carbide size to the extent that powder metallurgy can. Conventional steel is already forged and rolled down from several inches thick before a knifemaker buys it, and forging bevels into a knife won’t have much of an impact from there. You can watch my pattern welded Damascus video to see an example of extreme forging reduction of 154CM vs powder metallurgy RWL34.
Nice. What about cold forming with really high pressure? It works well on some traditional tools Like scythe (made From soft Carbon steel) really well And i was wondering if knife steels Can benefit From cold forming on the egde....
You said we shouldn't use your Magnacut data to justify forging vs. stock removal. I have a question though. Since the 100F/hour anneal would achieve a 1 point Rockwell improvement with the same Aust. temperature, would this be a good way to achieve more hardness (and roughly the same toughness) with less retained austenite for us stock removal guys, or would the difference be insignificant and therefore a waste of time and electricity?
I have some nitro V im wanting to use up before making the switch to magnacut would the 1600-1650 temperature for annealing be a good temperature range?
According to Dr Larrin , some bad shit. I think you get reduced toughness because your carbide structure is not nice and regular. After hardening you get big irregular carbides which is bad news for toughness
Firstly it wouldn’t be soft for drilling, cutting, etc. But also you would have excess carbon in solution and end up with lots of retained austenite and poor toughness after quench and temper.
i only know of like 2 or 3 guys that actually forge stainless steel, much less make stainless Damascus, and one of them is Devin Thomas. Honestly it's way above the skill/comfort level of most knife makers, even decent ones.
That is exactly what I want to see change. I think a lot of reasons for the limited use of stainless in forged blades comes from tradition and not necessarily from difficulty. With some more education I think it could become more common.
If I had two or three guys I'd forge stainless :) But yep its quite an uncomfortable proposition to move without presses, powered hammers or very big hammers and strikers. What little I've sort of done was welding 300 series stainless to high alloy and other stainless steels, with some percussive fettling to make it fit for various things- then followed roughly a process similar to what was presented here in a fairly large kiln. Its worth doing if you're doing enough of it to warrant the power costs for long hours of thermocycles, but for bit-pieces and one offs its going to blow out some cash pretty quick
Liquid nitrogen vaporizes when in contact with hot steel so it ends up being slower than you might think it would be. Plate quench or oil quench followed by liquid nitrogen is better.
There is a guy who did just that (quenching in LN2) and put it here on YT but I really don't remenber his name/channel. The steel was indeed much softer than what could be intuitively expected. Actually, what I was sure was going to happen is just sudden breaking and it was not what happened at all. I was surprised. 😮 The vapor that suddenly forms all around the part being quenched in LN2 prevents it from actually touching the steel, hence the not so drastic cooling rate which in turn doesn't harden the steel that much.
I am not sure about the claim that all steels are forged. Most of them are rolled or drawn. These processes are not equivalent to forging. Forging generally improves the micro structure and homogenizes the material. You get better mechanical properties and toughness increases. Drawing, rolling creates anisotropy in the material and causes lower strength in general. Forging is expensive and not done generally unless someone forks big bucks. ie an aerospace company...
You're right, of course, but if you want to know why bladesmiths don't pound on stainless steels, it's just because it sucks. Stainless steels simply refuse to move under the hammer. Plain and simple. For example. If you make axe-eye or hammer-eye drifts and you can't get your hands on H15 or similar; 416SS or AEB-L makes excellent drifts, because it's tough as nails and doesn't move, even when hot. (even titanium works ..) Just make sure you don't trow it in a water bucket when it's orange, or you'll harden it.
I have 2 wierd questions. 1) About sharp sword. Would powder metallurgy work for historical sword to make it stupidly hard, but not brittle to the point of impracticality? I understand that you can have defferent concentration of carbides, so is it possible to concentrate them more near the edge of blade. 2) About big, durable sword. What modern steel would be best for big durable sword? With big swords, problem is they become too floppy and thus not really practical. Any kind of super long sword would be worse then polearm with wooden shaft. Is there modern steel that would be several times stiffer then carbon steel and several times tougher then carbon steel. Ability to hold an edge is not very important here.
This was one of the rare chapters that was not described in your book in details. Thank you for your immense work!
Started forging my own stainless damascus recently. Your first question in the video is what i wondered for many months...
Thanks so much for this video
Thank you for doing that
So fed up with 1095 Damascus knives, I live on the coast
If I want my blade to turn into a bucket of rust on the coast, I can just buy a Walmart special
Thank you for moving onto stainless!
Fascinating stuff. That 100 degree per hour annealing result is quite surprising, and something I expect a lot of knife makers will be very happy to hear. Being able to let it go overnight could be a game changer for makers wanting to work with stainless who have limited themselves to low alloy steels.
Having knowledge and data like this available via UA-cam is so vital for the forging community. Thank you again for an amazing video!
Woooo it's a good day when Larrin uploads
So, I watched the video and I read the book; I'm still left with a question (maybe I read it and missed it); Why anneal at all? I will admit my introduction to knifemaking came from forged in fire, and those guys are making the entire knife start to finish in 5 hours, albeit with low alloy steels. I trust your research a lot more than my own knowledge. So lets say I'm just a guy in my garage that likes to swing a hammer. I like to make useful knives, so I like AEB-L kitchen knives. I forge to shape, Normalize (though I know now not to bother with that) and then I Austenitize at 1975 for 5 minutes and quench. What properties are my knives missing by not annealing in between forging and austenitizing?
You can’t drill or bandsaw cut hardened steel. Also the heat treatment response is different without the anneal. Even normalized low alloy steel heat treats differently. Annealed steel can be controlled better in heat treatment.
Loved the class at bladeshow, great to see some of that data presented again as there were some details that had slipped past me.
Thanks for all the hard work!
Thanks for your dedication to physical testing results and your expertise! This will help us knifemakers make better products faster!
Seriously I don’t know what we’d do without you. Thanks once again for your contribution to the community
Outstanding information. Thank you! AEB-L will be used for my third knife. I suppose I'll have to build an oven.
BTW - how ironic that UA-cam puts a Coolina knife ad during your video. From next level to the basement.
Thank you for the hard work behind sharing all this info.
You got game ! Nice video, and good education, your math is good...I deal with stainless steel for my day job and we have a lot of high tool scrap , I've been thinking about getting into blade making, working stainless is a thing, thank you for educating everyone and spreading the art of stainless steel metallurgy
Thank you. You spent the majority of time on annealing. I'm back here wondering how much carbon it loses in forging.
Exact about this I ask Larrin few days ago, about magnacut.
thanks for share to us 🤗
Great video!! Such an underrated channel
superb... great insight... Seth Burton (Cosmo on Salt Spring) forged my S90V/S35VN & S110V/S35VN (Stainless "Damascus") Ingots from which he formed my 2 favourite Custom knives... Now I know why they are so good blades
Thanks for making this video, it's really well explained and put together
That was the exact question i was thinking about recently, thanks so much Larrin !
I love getting educated by this dude. always amazing info and well described and demo'd.
Fantastic work. Thank you. Quick nerdy question. I am halfway through the video where you talk about the difference in hardness and toughness for the slower vs faster annealing of Aeb-l. Was this a single run? Triplicate? Was there error bars? Thank you!! What's the inherent error in the equipment? At what point are small changes significant vs noise. Excellent work!! Not trying to be a jerk. Just asking questions
Toughness and hardness was measured by averaging three coupons
@@KnifeSteelNerdsthank you.
I have my own desing made in 8670 and I love this steel sofar
Thank you so much sir, what a valuable resource your videos and data have been in my journey
It would be cool to see how different toughnesses translate in real life. Is a jump of 5ft-lbs noticeable? What does that look like when prying with the tip, hammering edge into hard material, etc.
Depends on the hardness. If the steel is 5ft-lbs vs 10ft-lbs 60hrc D2.. you'll NOTICE it at finer geometries. Even crazier would be something like the same HRC D2 vs AEB-L with like 5fl-lbs vs like 35 or something.
Nice. Do you know whether the forging part (both heating and compressing) is contributing to the improvements? Or is it possible that skipping forging and just re-annealing the steel from the manufacturer would have produced the same results?
The forging dissolves carbides before the anneal and the forging action prevents excessive grain growth and grain boundary carbide. I don’t know how much benefit could be gained by re-annealing as that is a test of double annealing while this was a test of properly annealing after forging
@@KnifeSteelNerds Gotcha, thanks. Could it also be that the manufacturer simply didn't do annealing as well as they could have, and you're improving the properties of the steel by doing it properly?
The reason I'm interested is that I do stock removal with Magnacut, and I have no way of knowing whether to trust the manufacturer's annealing process. Each manufacturer might be doing something different, it might change over time, etc. If heating to forging temp then re-annealing will get me both better, and more consistent results, I'd consider doing it.
Their annealing wasn’t done poorly, it’s just that our goals and equipment are different than the manufacturer. As I said in the video I think using the manufacturer condition is perfectly fine.
@@KnifeSteelNerds I didn't say they did it poorly, or intend to criticize them. I'm asking if the experiments you did actually provide any relevant data to support the claim that there is some improvement you can make to the steel through the forging process.
I'm sincerely trying to understand which conclusions are supported by the data and which are not. It doesn't seem to me the data supports any statements about whether forging helps or hurts. All we know is that forging + your annealing process showed improvement. Couldn't it be that your annealing was simply better? We don't know to attribute the improvements to forging vs annealing without comparing your annealing process with and without forging. Is that an unfair or incorrect conclusion?
The improvement was due to annealing differences
Such great info. Have you ever compared your methods to other industries? Anything from other form techs that might be interesting to experiment with?
Have you tested the toughness of ztuff with a 900 degree temper, or doing a triple temper at more typical temp ranges of 400 to 500 degrees Larrin? just wondering if there's any way to boost it's toughness up into the 55 to 58 ft lbs range.
Thanks
Thanks for this, I don’t understand the avoidance that some knife makers make towards stainless steel
I understand that 1095 is easy to work with
But geez
This is 2024, not 1955
We have the technology to have good knives now, I don’t want to have to stick my knife in a bucket of oil every day to prevent rust (live on the coast)
And I don’t want to have to sharpen my knives every time I use it
It’s time to move on from 1095 and low alloy steels
thermal carbide refinement should be possible wherever dissolution temp is below melting temp of the respective steel. obviously worse for high carbon steel alloyed steel but should work for many med carbon high alloy steels -- iirc for (unspecified) Vanadium carbide temp is around 1100C, lower for Cr, higher for Tungsten. aust/quench cycling should speed it up as usual.
I think it would have been really interesting to see an ingot steel with a lot more carbide than aeb-l tested like this.
I understand why you would pick aeb-l for this. I just think that would be where any bigger room for improvement would be.
Yeah, AEB-L dissolves totally very near the melting temp or before. D3 or D2 have carbides pretty much even in the crucible before it fully solidifies.. they can have huge carbides and conventional cheap D2 vs CPM-D2 is crazy tougher.
Unreal info!
would the short temper anneal have worked better if you had used a cryo cycle beforehand? or repeated short tempers? in tempering 2/3x 1-2h is the standard, why use something else for ~temper~ anneal where the same RA->Mart->ferrite/carbide conversions are at play??
No. That would only help if retained austenite was the issue
So with these high carbide content steels, does forging make powder metallurgy less relevant or does the even composition of the powder metallurgy steel still play a big part in making a better steel versus the smaller carbides that forging can kind of mimic?
Forging cannot reduce carbide size to the extent that powder metallurgy can. Conventional steel is already forged and rolled down from several inches thick before a knifemaker buys it, and forging bevels into a knife won’t have much of an impact from there. You can watch my pattern welded Damascus video to see an example of extreme forging reduction of 154CM vs powder metallurgy RWL34.
Interesting video!
Thank you for great info. 👍✌🇨🇿
Forgive me if you've covered this in a forum or anything but any thoughts on the Survive! Knives magnacut issues?
www.bladeforums.com/threads/survive-deserves-a-permanent-post-in-the-hall-of-shame.1613748/page-278#post-22549628
@KnifeSteelNerds this is why your so respected sir. Not only took the time to respond but don't shy away from anything less than full transparency 🫡🤝
Thanks for the imformation
Nice. What about cold forming with really high pressure? It works well on some traditional tools Like scythe (made From soft Carbon steel) really well And i was wondering if knife steels Can benefit From cold forming on the egde....
No
thank you
any plans to bring sg2 sucessor spg strix for analysis?
Nobody has it
You said we shouldn't use your Magnacut data to justify forging vs. stock removal. I have a question though. Since the 100F/hour anneal would achieve a 1 point Rockwell improvement with the same Aust. temperature, would this be a good way to achieve more hardness (and roughly the same toughness) with less retained austenite for us stock removal guys, or would the difference be insignificant and therefore a waste of time and electricity?
It got higher hardness because of more carbon in solution, which also leads to more retained austenite especially without cryo
@@KnifeSteelNerds Thanks. There's no free lunch.
I have some nitro V im wanting to use up before making the switch to magnacut would the 1600-1650 temperature for annealing be a good temperature range?
Nitro-V is nearly identical to AEB-L
@@KnifeSteelNerds
Why is its toughness so much lower then?
What happens if the steel is not annealed between forging and hardening?
According to Dr Larrin , some bad shit. I think you get reduced toughness because your carbide structure is not nice and regular. After hardening you get big irregular carbides which is bad news for toughness
Firstly it wouldn’t be soft for drilling, cutting, etc. But also you would have excess carbon in solution and end up with lots of retained austenite and poor toughness after quench and temper.
Thank you for replying! I assume similar things happen if it isn't soaked the full two hours before quenching or annealing?
i only know of like 2 or 3 guys that actually forge stainless steel, much less make stainless Damascus, and one of them is Devin Thomas. Honestly it's way above the skill/comfort level of most knife makers, even decent ones.
That is exactly what I want to see change. I think a lot of reasons for the limited use of stainless in forged blades comes from tradition and not necessarily from difficulty. With some more education I think it could become more common.
If I had two or three guys I'd forge stainless :)
But yep its quite an uncomfortable proposition to move without presses, powered hammers or very big hammers and strikers. What little I've sort of done was welding 300 series stainless to high alloy and other stainless steels, with some percussive fettling to make it fit for various things- then followed roughly a process similar to what was presented here in a fairly large kiln. Its worth doing if you're doing enough of it to warrant the power costs for long hours of thermocycles, but for bit-pieces and one offs its going to blow out some cash pretty quick
I’ve done all my high alloy forging by hand (AEB-L, CPM Cru-Wear, 3V, etc.). It’s definitely doable.
Ive reforged some stainless knives that broke, 1.4116, 420, 440. Seems easy enough to me
I was just thinking about this.....
I feel like 12 hour is a good hold time for temper anneals.
What would happen if you quench the blade in liquid nitrogen?
Liquid nitrogen vaporizes when in contact with hot steel so it ends up being slower than you might think it would be. Plate quench or oil quench followed by liquid nitrogen is better.
There is a guy who did just that (quenching in LN2) and put it here on YT but I really don't remenber his name/channel.
The steel was indeed much softer than what could be intuitively expected.
Actually, what I was sure was going to happen is just sudden breaking and it was not what happened at all. I was surprised. 😮
The vapor that suddenly forms all around the part being quenched in LN2 prevents it from actually touching the steel, hence the not so drastic cooling rate which in turn doesn't harden the steel that much.
Mmmm steel! 😋
I am not sure about the claim that all steels are forged. Most of them are rolled or drawn. These processes are not equivalent to forging. Forging generally improves the micro structure and homogenizes the material. You get better mechanical properties and toughness increases. Drawing, rolling creates anisotropy in the material and causes lower strength in general. Forging is expensive and not done generally unless someone forks big bucks. ie an aerospace company...
You need to do more reading.
Stainless high alloyed martensitic "monolithic" (sic) steels are today so good that it isn't even funny anymore.
You're right, of course, but if you want to know why bladesmiths don't pound on stainless steels, it's just because it sucks. Stainless steels simply refuse to move under the hammer.
Plain and simple. For example. If you make axe-eye or hammer-eye drifts and you can't get your hands on H15 or similar; 416SS or AEB-L makes excellent drifts, because it's tough as nails and doesn't move, even when hot. (even titanium works ..) Just make sure you don't trow it in a water bucket when it's orange, or you'll harden it.
First!
Buy a cheap atmospheric furnace from china 🤣 they wre very cheap
I have 2 wierd questions.
1) About sharp sword. Would powder metallurgy work for historical sword to make it stupidly hard, but not brittle to the point of impracticality? I understand that you can have defferent concentration of carbides, so is it possible to concentrate them more near the edge of blade.
2) About big, durable sword. What modern steel would be best for big durable sword? With big swords, problem is they become too floppy and thus not really practical. Any kind of super long sword would be worse then polearm with wooden shaft. Is there modern steel that would be several times stiffer then carbon steel and several times tougher then carbon steel. Ability to hold an edge is not very important here.