I’m interested in obtaining a chunk of Russian tank armor, to make some cooking knives out of.
Kind of curious what kind of steel a typical vintage tank is made of. Probably some kind of mid-carbon, given that “spalling” is an issue if the armor is penetrated. It’s probably somewhat hard but not martensitic. Naturally, the fancier tanks have layered armor, such as the US “chobham” armor that is on the M-1 non-export version – that’s got ceramic and a thin layer of depleted uranium in it. I am not interested in finding out how depleted uranium welds.
This thought inspired me to search in a few places, and it appears that military armor is not something that is readily obtained. There’s a sherman tank in Philipsburg not 10 miles from my house; I wonder if anyone would mind. Gun barrels are good steel, maybe just shorten it a bit?
I’ll just guess that a lot of jewelers would have one. I trained on an oxy/acetylene torch. (My own system is oxy/propane, as I have the torch in the laundry room and propane is slightly safer than acetylene.) However these particular torches tend to have very small tips and may not be up to that particular job. Farmers, maybe?
I do hear that none of the Ukrainians are being charged taxes for these tanks, so you may very well have access to bits and blobs at some point.
Chobham armor is of British origin and is named after the place where it was invented (Chobham in Surrey).
Anything older than a T80 should be safe and have no DU.
That said I’d hurry if you want some tank bits, Ukraine has a very large steel industry and those tanks will be fed to the fires pretty damn quick.
might be relatively easy to cobble together a “thermic lance” out of an oxygen tank and spare parts. Probably pretty dangerous, though.
I’ve never done it, but I am awfully tempted to try it one of these days…
I wonder if anything would be notably better than the springs from one of the abandoned (out of fuel/stuck in mud) trucks, which wouldn’t need too much in specialized equipment to get, and also wouldn’t be worth shipping half way around the world…
Do you have a way to determine the composition of the steel, if you obtained a chunk of it? or know someone/place who could?
Anyways, I’m mildly curious about this, if nothing else, there should be some novelty factor for a blade made out of an abandoned Russian tank…
That said I’d hurry if you want some tank bits, Ukraine has a very large steel industry and those tanks will be fed to the fires pretty damn quick.
I actually have several threads of enquiry out. I’m pretty sure that, if people think of it, it’ll be a popular “thing” – who wouldn’t want a yard implement made from genuine Russian tank armor? And, if it’s not high carbon, which I suspect it’s not, it’d forge up into some lovely knives – just take a chunk and hammer it out then forge-weld an edge of high carbon onto it, perhaps a twistmascus of 1095 and some gun-barrel.
lochaber@#3:
might be relatively easy to cobble together a “thermic lance” out of an oxygen tank and spare parts. Probably pretty dangerous, though.
I’ve never done it, but I am awfully tempted to try it one of these days…
(cough) (cough) it is pretty easy. What you need is steel brake-line, which even comes pre-swaged at the end so you can connect a hose to it. Ignite it with a propane torch as you slowly open the O2. It’s the O2 that does the cutting – an old welder’s trick is to cut huge pieces of steel with an OA torch by starting the cut with the OA then turning the acetylene off and just doing the cut with a thin needle of O2. Basically it’s “rusting very fast.” (I am still a huge fan of diamond cut-off wheels in angle grinders although they are noisier and less fun, they’re not as explody.)
I wonder if anything would be notably better than the springs from one of the abandoned
I like the symbolism of a tank better. That’s really the thing.
Steels like tank armor or truck springs are what I consider “mystery metal” – which I won’t use generally in a part of a blade that matters. It’s a waste of time to spend time working with something that is possibly garbage in a world that has 1095 and W-2 in it. That’s why I generally treat mystery stuff as just something to layer in a weld-up to use as a facing for something that is a known quantity, e.g.: wrought iron facings on a 1095 core. I’m sure Russian tank armor would make lovely patterns if you smelted it with some drill bits and charcoal and folded it a few times. My oroshigane knife is a rare thing for me – I would not have made the entire blade out of non-modern monosteel except I trust sensei’s sense of steel. And, as usual, my trust was well-placed.
Usually to check a steel for carbon content, you “spark test” it, which is just grinding it a bit and estimating the carbon content based on how the chunks knocked off burn in the air. It’s not hard once you’ve seen it a few times. That’s a check you’d perform before you invested any time in a piece. Once you had the piece assembled you quench it, and that’s going to reveal other things about the steel and you can hardness test it (I use calibrated files because serious rockwell testers are – oof $) and by then you’d be able to decide if it was worth polishing and finishing. After you’ve polished part of the steel and seen the grain, temper-line, and hardness, you’ve got a pretty good idea if you’re looking at something worthwhile. For example, my oroshigane tanto has a distinct “presence” to the blade – there is absolutely no “give” to it at all – it’s not springy, it doesn’t bend, it’s ridiculously stong (I whacked on the tang a bit for fun) and it is totally unimpressed by the puny human’s hands. I have mentioned in places here before that combat knives are very very different from cooking knives – well, the oroshigane tanto blade … you could ram that through someone’s sternum and pin them to an oak beam and let them hang from it in a way that a typical kitchen knife (or most of the crap that is sold as combat knives) could never approach.
I’m mostly concerned with repeatability. I want something that’s going to perform within expectations every time. That’s why I’d have no trouble fielding a Russian tank armor blade so long as the core was 1095 or W-2, because the user’s experience of the knife will be the 1095, and their visual experience will be the side-pieces of tankmascus.
Given the amount of tanks that have suffered ammunition cook-offs and turret launches,
there are plenty of pieces lying around.
Note that the later models of T-72 have composite armour for the upper glacis and turret. Not sure if that is very suitable for knives. See the wikipedia article for more details.
But lest we forget; any one of those destroyed tanks is probably a war grave. Unless the tank was abandoned when it was destroyed, a T-72 has a three man crew. The chances of them getting out alive of such an incident is probably not very high.
“the fancier tanks have layered armor, such as the US “chobham” armor”
Yeah, and fancier planes have faster engines, like the US “jet” engine, like those fitted to the US VTOL planes the Harrier. USA! USA!
Yeah. I’d be afraid that any tank out there might have some DU plating, whether US, Russian or anyone. The safety manual might not mention it. Unfortunately, while U-235 is much better for stimulated fission reactions, good old U-238 is equally radioactive when just sitting there or being cut or welded. So I’d want alpha and beta emissions data for any piece of scrap metal I kept around, even if I never welded it. Be careful.
the modern equivalent of swords into ploughshares
The soviet union had a lot of troops in eastern germany, which occupied a lot of land, a lot of which was used as training grounds. Some of those areas are still not cleaned up. The forests around Jueterbog / Altes Lager were used like that since imperial times and are (probably still) full of leftover gear.
Currently I have “boots on the ground” in Kyiv scouting for someone who has access to an AFV wreck.
rsmith@#6:
But lest we forget; any one of those destroyed tanks is probably a war grave.
And a crime-scene. Two great tastes in one spoonful.
I have read somewhere that during WW2 Russian T34 tanks had sometimes overhardened the turrets and they tended to delaminate shrapnel into the interior when hit as a result. But steel science has progressed a lot since then.
Tank armor and cannon barrel are definitively hardenable (and hardened) steel, but that is a really, really vague term. At what temperature should it be quenched? What heat soak time does it need for proper phase change? What is the optimum quench medium? Tempering time and temperature? The number of heat cycles? The questions are many and answers are difficult to find without knowing the exact composition of the steel in question. There is a limit to what can be found out at home.
Not to mention that if the steel has high vanadium content, even annealing it can be a challenge and impossible to do without special equipment. I have once tried to anneal a piece of very hard steel, a steel-cutting saw blade. And even though I heated it to 900°C and held it there for a while, it remained hard. And my experiments with N690 have shown that even that is very resilient to annealing once hardened.
I think it should be possible to send a piece for analysis, there surely are laboratories in the USA that would do that for a price. Typically such tests cost somewhere in three to four-digit numbers though.
A blade made from a Russian tank blown up in Ukraine would surely be a valuable collector’s item if nothing else. And even if treated sub-optimally, any piece of steel with an edge and a point will cut and stab,
At what temperature should it be quenched? What heat soak time does it need for proper phase change? What is the optimum quench medium? Tempering time and temperature? The number of heat cycles?
Oh come on. You know I treat blade-facings differently from edge/core. So usually I’m dealing with W-2 or 1095 which are well known steels with good behavior.
There is a tradition in Japanese blade-making where you forge a blade of any old crap and forge-weld a piece of hitachi blue on one side to make the edge. That bypasses all those questions, since you’re now dealing with the parameters of high carbon steel. I.e: normal temp is 1750F and quench is 1400F-1500F.
If I manage to get some panzermetall I’ll see if I can forge-weld it or if It needs an O2 free environment. If that doesn’t work I’ll make oroshigane of it and forge-weld that into san mai. I have already successfully stuck 304 stainless to 1095 in san mai so I can probably sandwich anything unless somehow Russian tank has a melting temperature higher than wrought iron. “If it’s a puddle it’s welded.”
My bet is its mostly mild carbon steel, with impurities and it’d make a pretty twist with some 1095. We may see. The guy I’m talking to is asking about dimensions and shipping. I’m not looking for a whole tank, probably just a chunk of armored skirt.
@Marcus, my understanding of metallurgy does not exceed that of a high-school chemistry teacher so my word certainly is not a gospel of truth on this matter since I am writing from the top of my head.
But I do not think you contradict me? Because that was my point exactly, W-2 and 1095 are steels that are suitable for this sort of quenching, armour steel from a tank however might or might not. Steels with high vanadium and/or chromium content, even when they are suitable for blades (like the N690 with which I usually work) are not suitable for this sort of hardening because they have a higher heat-soak time required for proper phase change and they also harden when cooled less rapidly (air quenching). That means that covering the spine with clay does not help neither during the heating – the heat creeps through the blade under the clay during the needed soak time – nor during the quenching – the clay cannot stop the cooling of the spine for long enough to matter that much. That is why differential hardening with hamon works best with low-alloyed high-carbon steels and the fancier the steel, the more difficult it becomes.
If I had to hazard a guess, I would think that tank armor steel is not mild steel (that cannot be hardened at all) and not high carbon steel either, but somewhere in the middle, akin to spring steel. And in the newest and modernest tanks the tank contains probably several different alloys even on the outside. Maybe even with carburized/nitrided surfaces. Who knows. I don’t.
I am sure that you could make a nice blade out of it if you get your hands on some, and if you use it for san-mai with 1095 for the cutting edge, It could be a real high-performance one. And as I said, it would probably be a valuable collecto’s item at any rate.
I do not mind working with “mystery steels” especially if it is for fun.
Hikers find rare WW II Canadian tank ‘rusting peacefully’ in English field
If more folks were to beat their tanks into tantos, there might be enough deterrence to go around, and rather less than more war anymore.
I’ll try to see what I can do after the Russo-Ukranian border comes to rest.
https://washingtonspectator.org/letters/#seitz