I stumbled across this while I was researching the metallurgy of battleships.
For those that aren’t into this stuff, there were all kinds of risible situations that cropped up in the transition from wooden ships to iron/steel ships. My favorite is the one attempt by a british shipyard to prevent rust by copper-sheathing the hull of a ship, which made it a sort of gigantic galvanic battery-powered rust-making machine. The transition happened in the 1890s and the physics of a lot of stuff was not fully understood. Nor was the behavior of various metals under various stresses.
I was listening to a great piece by youtuber drachinifel, who does extensive and detailed naval histories that are like opiates to me: I want more, instantly. In that piece, he described how there was a particular formulation of steel that was used in one of the early China raiders, that produced a remarkably tough warship, which produced warships that splintered to pieces under impact in the cold waters of the North Atlantic. I can see how a difference of a few tens of degrees can make a difference but, damn, that’s one of those “close, but no cigar” situations.
Anyhow: what is a battleship’s plates made of? The answer is: [firearmsblog]
Japanese Vickers Hardened (VH) face-hardened, non-cemented armor (used only on YAMATO-Class battleships)
ELEMENT.....PERCENT (By Weight)
CARBON-------0.48
MANGANESE----0.39
PHOSPHORUS---0.016
SULPHUR------0.026
SILICON------0.18
NICKEL-------3.67
CHROMIUM-----2.13
MOLYBDENUM---0.06
COPPER-------0.12
There are crazy things hidden inside of such a simple recipe – namely, how does one “face harden” the plates of a battleship? I don’t know. But I suspect it’s not a simple thing.
At the bottom of this posting, I will embed one of drachinfel’s videos, which is amazing, informative, and terrifying. It’s an analysis of the almighty whanging the the Seydlitz suffered at Jutland, explained with the help of a model that gets subsequently poked full of holes. It’s worth a few minutes of your time, to imagine what it must have been like for the crew of that great big metal thing, who were trying to keep it buoyant under exceptional circumstances. I have trouble wrapping my mind around the idea of “2 foot thick steel armor belt around a ship the size of a shopping mall” and then “shell punched right through the armor without slowing down then bounced around inside the ship before exploding.”
This, however, tells the tale:
That is a chunk of the Yamato which the US appears to have cut off and hauled to the surface, never minding that the ship is a war memorial because I suppose it’s just a Japanese war memorial. But, anyhow. It seems impossible to ask humans to stand in the path of forces like that. Remember that one of the big killers in the age of wooden ships was splinters? It does not appear that the problem of splinters was solved at the time of Yamato‘s sinking.
I remember reading John Keegan’s The Price of Admiralty which I sort of thought was good, but it’s a bit British, if you know what I mean? Then there is Massie’s Castles of Steel [wc] which is a great read with a ton of details. And there is the magisterial Holloway Frost’s The Battle of Jutland, [wc] written in 1936, which tracks the flight and impact of every known shot. I made the mistake of checking it out from the library as a kid, hauling it home, and trying to read it. It’s … amazing. If you want a feeling for what it’s like, watch the video above then multiply it by all the ships that were at Jutland and you’ll have a rough idea.
Our civilizations are built on blood and bones, and the fine pink mist that is often all that’s left of a young person.
What do I say to these ghosts that keep coming round again?
What do I say to these ghosts that keep coming round again?
We was just kids doing the dirty work for the failures of old men
– Ray Wylie Hubbard
Surely you fill the hull with water, blowtorch the outside until that’s red hot, then roll the hull down the slipway into the water to quench it. What could be difficult about that?
That is a rather impressive hole. Where is it at now? It looks like a park, and it hopefully has memorial plaques to the poor sailors who were inside it.
Marcus ~ how does one face harden the plates of a battleship?
Carbon and heat. Face hardening is just case hardened metal, and is a similar process to what you did when you put your steel into that case and heated it up. Modern equipment controls the heat and cooling rate, but it’s still the ancient blacksmiths technique of packing charcoal and bone around the iron in the case.
Wiki
Bulat steel involved some specific woody stems and roots of plants as ingredients in the charcoal and in the quenching water. I can identify only one from the description (Restharrow) but it’s a deep and extremely tough rooted perennial legume, whose roots and stalk would contribute small amounts of silicon, chromium, and molybdenum along with the carbon.
this is the ship they hauled up and turned into a spaceship to fight the gamilons, right?
Here is the story of the armor piece you have above. Artifact Spotlight: Yamato Armor The short of it is that the plate was intended for a Yamato class ship but was found in Kure Naval Base after the war. It doesn’t come from the Yamato itself.
JM@#4:
Here is the story of the armor piece you have above. Artifact Spotlight: Yamato Armor The short of it is that the plate was intended for a Yamato class ship but was found in Kure Naval Base after the war. It doesn’t come from the Yamato itself.
Thank you for that. As I kind of waved my hand past, I was concerned that someone had retrieved part of the actual ship itself, which would be kind of uncool to feature in your hole-making museum.
Also, as Great American Satan@#3 points out, the ship was hauled up and turned into a space ship, so it’s not even down there anymore. Although the broken in half wreck and scattered pieces was probably put there by space aliens as part of the plot.
xohjohn2n@#1:
Surely you fill the hull with water, blowtorch the outside until that’s red hot, then roll the hull down the slipway into the water to quench it. What could be difficult about that?
Sounds legit.
I want to see the blowtorch they use for that.
Tethys@#2:
Carbon and heat. Face hardening is just case hardened metal, and is a similar process to what you did when you put your steel into that case and heated it up. Modern equipment controls the heat and cooling rate, but it’s still the ancient blacksmiths technique of packing charcoal and bone around the iron in the case.
It sounds to me like the way the ships were constructed involved a lot of heating and hammering, which would imply that the steel was doing what today we would call “work hardening” – which is quite legit since you’re changing the crystalline structure of the metal and distributing the carbides around in it and that makes it tougher. Later in the article I referenced, are some comments from the Naval Research Labs that the steel wasn’t really as good as the Japanese thought.
Well, if you listen to what the Yamato went through before it finally sank, I think the steel was not bad. The ship got peppered with a small infinity of bombs and something like 10 torpedoes. That’s Seydlitz-level pounding.
The whole story of how Yamato came to be out there, and what it was trying to do, is deeply moving and depressing to me. It’s foolhardy military glory. A total waste.
is a similar process to what you did when you put your steel into that case and heated it up
That was Charly. He was trying to figure out how to not lose an investment in time that he made on a piece of “mystery metal” – much respect to him for doing that and making it work. Me, I use nice yummy bars of high carbon steel that are all smelted to a particular assay and laboratory tested for the correct alloy. I’m much lazier than Charly.
Our orishigane that I made osoraku out of was also an opportunity to get some mystery metal on the anvil, but I was pleased when Sensei pulled out some laboratory assayed iron, and then carefully weighed out the admixtures. Often on youtube when someone is making bulat, they take a bunch of stuff and melt it, spark test it, and call it OK. There are a lot of reasons I won’t do that, especially in eastern Europe. I am aware of the migration of metal components out of the Chernobyl exclusion zone because I visited the tank graveyard and noticed they are all missing cylinder heads, carburerators, generators, etc. There were tons of Zil trucks there, too, and the spare parts moths had really eaten those. I wouldn’t want to make a cooking knife out of something radioactive, though I wonder what forging would do to the nucleotides? Would they leave the steel and go up my nose? Enquiring minds maybe don’t need to know.
More seriously, everyone who does blacksmithing eventually knows someone who gets a chunk of something that is galvanized, and heats it up, breathes in the zinc and cadmium, and is in deep fuck for the rest of their life. I love my pristine library of high carbon steels!
The contamination that’s still around is Strontium-90 and Caesium-137. Ceasium is probably going to boil out at forging temperatures, so the final knife will be safe but maybe not the smith. It sounds like Strontium would dissolve into the metal at forging temperatures and also form scale, so maybe trace amounts coming out of the knife during use?
I’m not a metallurgist, but my conclusion is to leave the mystery Chernobyl metal alone
Marcus @8
I should have specific your canister Damascus post, and case. I remember Charly doing the actual carbon enrichment too, an impressive bit of smithing! I think wootz is actually the Viking term btw.
I imagine that steel plate gets made, and then only the outer face is coated with carbon and heat treated/ cooled slowly in a sealed case. The softer metal underneath is more shock absorbing and helps prevent the face from fracturing on impact.
The feathering fractures (top right side of the hole) visible on that hunk of armor in the video run parallel to the surface, which indicates that the face hardened layer fractured away on impact. Like an ice sheet.
The feathering stress fractures are given a closeup for a few seconds starting at 2:50 in the video linked by JM @4. You can also see that the impact sheared away very defined layers of the surrounding surface.
It’s amazing to see how hardening worked. The outer layer has fractures that look like glass; underneath that, it crumbled like stone; and the bulk of the plate behaved like clay.
It’s also frightening to think of the violence on an impact that makes steel behave like clay, and what it would have done to the much softer bodies that steel failed to protect…