[HN Gopher] How to build a 50k ton forging press
       ___________________________________________________________________
        
       How to build a 50k ton forging press
        
       Author : chmaynard
       Score  : 214 points
       Date   : 2024-08-21 14:00 UTC (8 hours ago)
        
 (HTM) web link (www.construction-physics.com)
 (TXT) w3m dump (www.construction-physics.com)
        
       | cbsmith wrote:
       | ...and now the modern equivalent is the Giga Press:
       | https://cleantechnica.com/2024/03/09/teslas-giga-press-has-l...
        
         | mitthrowaway2 wrote:
         | Not only is the giga press mentioned in the article, it's very
         | far from being an equivalent to the Alcoa 50,000.
        
           | cbsmith wrote:
           | Yes, it is mentioned in the article, and it specifically
           | says: "We can see a modern, obvious parallel between the Air
           | Force Heavy Press Program and Tesla, which has created a
           | similar revolution in car manufacturing by using large
           | aluminum castings to replace dozens or hundreds of smaller
           | parts."
           | 
           | So I didn't think what I said was out of line. Obviously, I
           | was mistaken.
        
       | tra3 wrote:
       | Super interesting:
       | 
       | > The largest, the 50,000-ton forging presses, were behemoths:
       | each was the size of a ten-story building, and could exert enough
       | force to lift an entire battleship. The 35,000-ton forging
       | presses weren't much smaller.
       | 
       | and then
       | 
       | > Following Germany's surrender, the U.S. and the Soviet Union
       | divided up its large press capabilities as well as its rocket
       | scientists. The U.S. dismantled four German presses and had them
       | shipped back to the states
       | 
       | I wonder what the logistics for moving something like that across
       | the ocean was. I know Soviets dismantled a bunch of factories
       | during the war and moved them far behind the front lines...wonder
       | what that was like.
        
         | dimator wrote:
         | There's an excellent video on these presses
         | https://youtu.be/hpgK51w6uhk?feature=shared
        
         | hinkley wrote:
         | Well when you have military supply vessels just hanging around
         | in the area...
        
           | tra3 wrote:
           | For context, I work on my car a bit, and the shop manual for
           | it is hundreds of pages (thousands?). Now scale it up to a
           | factory, maybe without manuals. Disassemble, crate it,
           | assemble it 5000 miles away.
           | 
           | Based on my software experience, I can sort of go in blind
           | and figure out how a system functions. I suppose that
           | translates to real world too..
        
             | hinkley wrote:
             | There's a UX school that says that if the user needs the
             | manual you fucked up. I mostly subscribe to that school.
             | Mostly.
             | 
             | It drives my family nuts that I will assemble a piece of
             | furniture without reading the instructions. But the thing
             | is with a little mechanical sympathy, and a well designed
             | product, there's only one sensible way for the parts to go
             | together, and if you organize them right while you
             | disassemble it (granted, harder to do when shipping
             | overseas) then you're good.
             | 
             | Imagine you had a device where four hardened steel bolts
             | held the critical parts together. It would be stupid if the
             | handles used the same bolt sizes in mild steel, right?
             | Someone will fuck that up and use the wrong spare parts or
             | do deep maintenance wrong. You'd use a different size bolt
             | so they can't get mixed up.
        
               | WheatMillington wrote:
               | Your viewpoint is rather naive in the mechanical world.
               | OK it's enough to assemble a coffee table, now try an
               | engine with 2,000 parts. Without a manual how can you set
               | bearing clearances? How do you know how much thrust
               | clearance there should be? How do you know which way up a
               | piston ring goes, or how much torque to apply to a head
               | bolt?
               | 
               | Machines are extremely complex, and that's before you
               | even touch electronics and hydraulics, both of which are
               | highly complex systems. Simply moving large machine parts
               | safely requires documented procedures, let alone order of
               | assembly.
        
               | kragen wrote:
               | there's a lot of shade-tree mechanics who have
               | successfully rebuilt engines with thousands of parts.
               | essentially figuring out how to rebuild an engine is
               | similar to figuring out how to build one from scratch,
               | which is within human capacity, particularly with
               | background knowledge. but the guy rebuilding the engine
               | has a lot of hints
               | 
               | granted, he'll probably fuck up his first two or three
               | pretty good without haynes or chilton
        
               | hinkley wrote:
               | There is a lot of stuff you can do when it's pass fail.
               | As a pro you have a time limit and you're bad if you
               | can't rebuild in X hours.
               | 
               | My dad will tell you I helped him rebuild a bike coaster
               | brake at 14. But the truth is the only decision he made
               | was to buy the repair kit. I got rags and laid all the
               | parts out like an exploded diagram, we cleaned them or
               | swapped them and they went back in the way they came out.
               | 
               | I worked as a bike mechanic for two summers in college.
               | Cars have manuals and maybe the mechanic you work for has
               | them. Bicycles do not. You're all shade-tree until you've
               | seen everything a couple times.
        
               | kragen wrote:
               | yeah. thank god for sheldon brown
        
               | hinkley wrote:
               | Does every car mechanic have the entire Chilton's catalog
               | or do the mechanics just have to memorize things or look
               | them up on the Internet? My understanding is it used to
               | be a little A and a lot of B, and now it's a mix of B and
               | C
        
               | WheatMillington wrote:
               | I was using the engine example as an analogy in an
               | apparently failed attempt to help you appreciate the
               | complexity involved. Mechanics in general will feel their
               | way around an issue, but almost universally have access
               | to paid repair databases when non-intuitive and complex
               | issues come about.
        
               | tra3 wrote:
               | I think everyone has access to full shop manuals in soft
               | copy these days. I imagine it's a lot like writing code.
               | You remember how to write a for loop (oil change? a
               | brakes?) but have to look up API docs for more esoteric
               | functions (a clutch job?).
               | 
               | FWIW here are Nissan factory manuals in all their glory:
               | https://www.nicoclub.com/nissan-service-manuals
        
               | sushid wrote:
               | Sure, but now you have another bolt and nut configuration
               | that requires a different drill, maybe a new supplier,
               | etc. RTFM!
        
               | hinkley wrote:
               | Bolts and nuts in two different materials/grades are
               | still two separate pieces of inventory to manage.
        
       | bee_rider wrote:
       | They talk about machining, casting, and pressing. Mostly with
       | casting and pressing in a good light, machining not so good.
       | 
       | As somebody who knows absolutely nothing about this stuff, I
       | wonder--casting, I thought, was generally a lower quality option
       | (like cast iron doesn't have fantastic high-performance material
       | qualities, and I had some crappy cast pewter toys as a kid). Are
       | there different, higher quality casting processes, and I've only
       | seen the bargain bin results? Is there a general ranking of the
       | quality of the result or is it all very complicated and material
       | specific?
        
         | debacle wrote:
         | Casting isn't necessarily "lower quality," it just has
         | different properties. It's also much older (by thousands of
         | years) than machining or pressing, but you can't get to the
         | pressing or machining step without having an ingot, which comes
         | from the casting process.
         | 
         | The main drawbacks of casting are you get a hard, but brittle
         | product with (generally) uneven quality. There are processes
         | (like annealing, though I don't know how you anneal a massive
         | component) that can solve these problems, but all iron/steel is
         | "cast" at some point.
        
           | BlueTemplar wrote:
           | Until the mid-1800s, basically only the Chinese used cast
           | iron, since it's so brittle. Ingots would come from smelting,
           | not casting.
        
           | kragen wrote:
           | depends on what you mean by 'machining'. grinding is at least
           | 7000 years old https://en.wikipedia.org/wiki/Shoe-last_celt
           | and roughly contemporary with pottery. casting presumably
           | began with pottery but was definitely in full swing by the
           | bronze age, a mere few thousand years later
        
         | WJW wrote:
         | Machining is fine, but in the context of the article the
         | problem is that it usually starts off from plates or otherwise
         | block-shaped materials. That means that if you have a weirdly
         | shaped part full of holes and/or with many protrusions in weird
         | angles (as vehicle parts tend to have), then you either have to
         | combine many smaller parts into a final part or have to machine
         | away a huge amount of material from a solid block to come to
         | the final shape. It would be much better to cast or forge the
         | part into roughly the right shape straight away, so you'd need
         | only minimal finishing work. That is what these presses
         | enabled.
        
         | hwillis wrote:
         | > like cast iron doesn't have fantastic high-performance
         | material qualities
         | 
         | Cast iron is a material, not a process. It's an unfortunate
         | legacy term for very high carbon steel (>2% by weight, or <11
         | iron atoms per carbon atom). For reference "standard" steel is
         | ~.08-.18% carbon, and high-carbon steel is ~.8% carbon.
         | 
         | The >1% carbon precipitates out into graphite within the steel,
         | causing it to behave totally differently. Less rusting, but
         | weaker and much more brittle when solid. Less viscous when
         | liquid, so you can cast long and thin parts.
         | 
         | > Are there different, higher quality casting processes, and
         | I've only seen the bargain bin results?
         | 
         | There are, but it mostly is independent of the material. Some
         | turbine blades are cast as single crystals for heat stability;
         | you can't really cut a single crystal without introducing
         | cracks and issues. There's also vacuum casting and spin casting
         | (using a centrifuge to force liquid into the mold), which lets
         | you cast metals that react with air or cool too quickly for
         | normal methods.
         | 
         | Most of the variation in process is about the final form you
         | cast into, though. Engine blocks are sometimes cast into a one-
         | off ceramic shell that is sprayed onto a sand form. It's an
         | expensive process but it lets you do the whole thing in one
         | step.
         | 
         | > is it all very complicated and material specific?
         | 
         | It is very material specific. Fundamentally its all about
         | shaping the grains. In many steels you can physically alter
         | grains. In others, like precipitation grains (aluminum alloys,
         | some steels) the structure is determined by the cooling and you
         | can't physically shape them. In that case you may often get a
         | better structure by casting since you can choose how to cool
         | parts down, while a billet will have a homogenous structure
         | that is usually worse towards the center.
        
           | hedgehog wrote:
           | Monocrystalline turbine blades are one of those things that
           | make me appreciate how deep the state of the art is for a lot
           | of "simple" things when you look closely.
        
           | pfdietz wrote:
           | > The >1% carbon precipitates out into graphite within the
           | steel, causing it to behave totally differently. Less
           | rusting, but weaker and much more brittle when solid.
           | 
           | If one adds some magnesium or cerium to the alloy, the
           | graphite precipitates out as spherical nodules rather than
           | feathery dendrites. The resulting material, called ductile
           | iron, is much less brittle than traditional cast iron.
           | 
           | An advantage of the higher carbon content is a reduction in
           | the melting point (by > 300 C), so the material is easier to
           | cast than low carbon steel.
        
         | mrob wrote:
         | They also talk about forging. Forging can produce higher
         | quality parts because metal has a grain structure. Just like
         | wood, it's easier to break between grains than across the
         | grain. Forging is deforming the metal without melting it. If
         | the temperature isn't too high, it will deform the grain
         | structure along with it. The grain can be aligned to make the
         | metal stronger along the axis where it needs to resist the most
         | force.
         | 
         | Wikipedia has a image of an connecting rod that has been etched
         | to show the grain:
         | 
         | https://upload.wikimedia.org/wikipedia/commons/5/5c/ForgedCo...
         | 
         | You can see the grain has been stretched along the length of
         | the narrow parts. Wrenches are another example of something
         | that's commonly forged for this reason.
        
         | colechristensen wrote:
         | Cast iron is a material, it's good for what it's good for but
         | its material properties don't really come from the casting
         | process, just the ratio of iron to carbon.
         | 
         | Casting has problems with thermal expansion, plenty of
         | materials shrink significantly as they cool and complex parts
         | cool unevenly which can cause them to break or deform.
         | 
         | Casting has problems with microstructure, plenty of materials,
         | especially steels develop complex crystal structures with
         | multiple phases of materials as they cool from liquids and even
         | extensively in hot solid phases. It's hard to control this in a
         | cast part.
         | 
         | Casting has problems with precision. The molds just can't be
         | all that precise when in machining, a thousandth of an inch can
         | be a relatively large distance.
         | 
         | However casting gets a bad reputation because most of the time
         | you see it it's because it's actually very cheap, cheap
         | materials, cheap process, minimal post processing. Higher cost
         | things don't necessarily realize the savings from casting as
         | much so they don't use it. And also a lot of higher quality
         | materials have higher melting points which require more
         | advanced tools to melt and handle.
         | 
         | Plenty of things though are cast and then machined, you notice
         | this if you look.
        
         | spenczar5 wrote:
         | Castings can achieve shapes that are impractical to machine. A
         | classic example is a spoked wheel. The spokes are really hard
         | to make precisely with machining, but fairly straightforward
         | when casting. Bandsaw wheels are virtually always cast, for
         | example.
         | 
         | Also, the processes are not really independent. It can be much
         | cheaper to do a rough casting, and then machine just the
         | critical faces of it, instead of using an "off the shelf" hunk
         | of metal and machining it all into shape. So it's not really
         | "casting is superior to machining" or vice versa. More that
         | machining is high precision but expensive. Casting has some up-
         | front cost but once the patterns are made, each item will use
         | material quite efficiently.
        
           | IshKebab wrote:
           | Spoked wheels aren't cast because it's hard to machine them.
           | You can easily CNC them if you really want. But that would be
           | insanely expensive and wasteful and not any better.
        
             | spenczar5 wrote:
             | Yes, I said "impractical", not "impossible".
        
               | IshKebab wrote:
               | You said
               | 
               | > The spokes are really hard to make precisely with
               | machining
               | 
               | That is not true.
        
             | buildsjets wrote:
             | I've watched enough Chip Foose on TV to know that in the
             | custom car world it is commonplace to start with a solid
             | blank wheel and CNC away 90% of the face to achieve any
             | particular design. It takes only minutes, and unlike
             | casting or forging you do not need to purchase hard tooling
             | for each different design.
             | 
             | https://www.youtube.com/watch?v=nqOlM6-YIIs
        
         | bagels wrote:
         | Other materials can be cast, such as various aluminum alloy.
         | Casting can have a higher cycle time, be cheaper, and require a
         | less expensive equipment.
        
         | bluGill wrote:
         | Which cast iron? There are many different grades/alloys with
         | different properties. Sometimes cast iron (some specific grade)
         | is better sometimes it is worse. And of course you can cast
         | things other than iron, cast steel does exist (rare outside the
         | feed to a press, roll, or some other process, but you can cast
         | steel into a specific shape if you want to). There are trade
         | offs. The topic is so broad we cannot even start to talk about
         | it. Instead we start with what your application needs and then
         | look at the options to get that.
         | 
         | Cast iron is fantastic for building machine out of - while it
         | isn't as strong, it is stable against vibration. There is a
         | reason engine cylinder selves are often cast iron.
         | 
         | > I had some crappy cast pewter toys as a kid
         | 
         | Those were pot metal, not pewter (pester has many definitions
         | but implies some qualty control). They are made out of whatever
         | melts in a pot - often whatever is cheap at the recycle yard
         | (without trying to identify what is in the metal - including
         | lead which shouldn't be used in toys). Typically no control of
         | the alloy was made and often they start with several different
         | things that are great in isolation but when mixed result in bad
         | behavior. Then the next time the make the toy they use
         | different mix and get different properties. If you spend a
         | little extra to get a known alloy pot metal is a high quality
         | castings with great properties.
         | 
         | > I've only seen the bargain bin results
         | 
         | You have likely seen a lot of non bargain bin results. However
         | since the parts are invisible you never thought about it or the
         | alloy used. You see the failures and so casting gets a bad
         | reputation because it is obviously used in the cheapest things
         | with low quality control. (the door knobs in your house are
         | likely cast pot metal plated with brass, but they last for
         | decades)
        
       | Metacelsus wrote:
       | Now I want to see one of these on the Hydraulic Press Channel!
        
       | jcgrillo wrote:
       | My little 20 ton shop press brake can bend 5/8" plate. Incredible
       | to imagine what this behemoth can do...
        
         | kibwen wrote:
         | Using advanced math I hereby extrapolate that this 50,000 ton
         | press can bend 12,500/8" plate.
        
           | hwillis wrote:
           | The second moment of area is quadratic with thickness (t^2),
           | so 250/8" plate. But in reality 2-3x more than that, because
           | at that scale steel gets a bit... goopy.
        
             | kristjansson wrote:
             | I understand very little about machining, expect that _all_
             | materials are kinda squishy if one applies enough squish.
        
               | mikewarot wrote:
               | Even inconel is bubble gum in a Kurt vise if you're
               | chasing tenths, or microns.
        
           | jcgrillo wrote:
           | well the next time I need some 130ft thick brackets I'll ask
           | them whether I can use it after hours or on the weekend
           | 
           | EDIT: or, according to hwillis' math, 2.5ft thick. I guess
           | those could be useful for anchoring a zipline to the moon or
           | something.
        
             | hinkley wrote:
             | I saw a guy weld 1.5 or 2 inch plate once to repair the
             | bucket on a giant bulldozer. That was... interesting. I was
             | trying to figure out why he left such a big gap until he
             | started welding. He had to fit the head in to lay down
             | layer after layer of welding bead to join the pieces at
             | full depth.
             | 
             | How would you weld even one foot of steel?
        
               | jcgrillo wrote:
               | For a butt joint V it out on both sides and do many, many
               | passes. Maybe have a few guys with rosebud torches
               | working heat into it as you go. Big rods make it go
               | faster (https://youtu.be/j61ezBX-EyA). For a lap joint
               | it's the same idea, you're going for a great big fillet.
               | But if you have a gigantic press at your disposal there
               | are other options. For inspiration:
               | https://youtu.be/k_LA_R4ifYk
               | 
               | The idea behind forge welding is you get both parts
               | nearly molten (e.g. "welding heat") then your hammer blow
               | (or the pressure from a huge press) puts enough energy
               | into the weld area to briefly melt it.
               | 
               | Also, hot rivets might be a better option than welding if
               | you can get away with it.
        
               | buildbot wrote:
               | Explosively?
               | https://en.wikipedia.org/wiki/Explosion_welding
        
         | js2 wrote:
         | Letterman being silly with an 80 ton press:
         | 
         | https://youtu.be/0CqCLf4RUUY
        
           | eric_the_read wrote:
           | A worthy predecessor to the Hydraulic Press channel:
           | https://www.youtube.com/channel/UCcMDMoNu66_1Hwi5-MeiQgw
        
       | PaulHoule wrote:
       | Nobody in North America has a press that can make a vessel for a
       | nuclear reactor without making it in pieces and welding them
       | together (probably adding a year to the schedule if you don't use
       | a new welding technique just developed in the UK not to mention
       | people being anxious over the welds)
       | 
       | There is a Canadian company that is gearing up to make small
       | reactor vessels like the BWRX-300 but so far I haven't seen a
       | sign they aren't Nuscale 2.0
        
         | phiiiillll wrote:
         | Was curious about what welding technique you meant, looks like
         | it is local electron beam welding
         | https://www.thefabricator.com/thewelder/blog/assembly/sheffi...
        
           | PaulHoule wrote:
           | That's it.
        
           | MisterTea wrote:
           | I work in an EB shop doing everything from welding,
           | engineering assistance, machine repairs, and complete machine
           | rebuilds. It's quite an impressive process and Ive had parts
           | in my hands that come from some of the biggest names you can
           | think of in aerospace, semiconductor, military, medical and
           | more.
        
             | hinkley wrote:
             | Are they for prototypes? Or how do you service production
             | runs for parts?
             | 
             | If for arguments sake it were a part for an AWACS or an
             | aircraft carrier you might only need to make eight or a
             | dozen. But even military aircraft tend to run into the
             | hundreds.
        
               | MisterTea wrote:
               | We do production runs with the rare service run. Most
               | parts are one time use as you might imagine. Service work
               | is the rare mold repair.
               | 
               | We are part of a few companies just in time manufacturing
               | so they pay for expedite processing on orders as small a
               | one piece to a few dozen. And we can get production run
               | orders in the tens of thousands.
        
             | mensetmanusman wrote:
             | 50 kW ebeam?
        
               | MisterTea wrote:
               | We have 7.5 kW and 15 kW machines. Smaller chambers but
               | there's plenty of smaller work out there.
        
       | hwillis wrote:
       | > Forgings have the added advantage of variable grain direction
       | which generally can be tailored to the stress patterns of a
       | specific design.
       | 
       | This is a super underappreciated fact! It's often repeated that
       | forging is just stronger, but just squishing steel does NOT make
       | it stronger. Forging a part is so much more than just smashing it
       | into a shape.
       | 
       | Steel cable is made of pretty ordinary steel which is stretched
       | 100s of times its original length. That process alone makes it
       | _2-4x stronger_ in that direction. You stretch steel and it gets
       | stronger in that direction.
       | 
       | Do you see how complicated that optimization process becomes? The
       | process steps are not just trying to take it to the final shape.
       | Your piston rod needs to be strong lengthwise, so you actually
       | want to start with a short fat ingot and stretch it out instead
       | of one that is near-final size.
       | 
       | Think of making an I-beam. You could hammer out the middle,
       | making it thinner. That would give you a bit of strength there
       | but very little on the edges. If you instead pull the edges out,
       | you create a long continuous stretch that will be very strong
       | against bending. Where, how, and in what order you stretch makes
       | all the difference. You may want to leave extra material and cut
       | it off later, so that your grains are all oriented together
       | instead of tapering to a point.
       | 
       | For any moderately complex part, this process is as complicated
       | as modern engineering problems. With poor steel you genuinely
       | need to understand how to foster and bring out those continuous
       | lines or your corkscrew will unwind like playdough. Blacksmiths
       | had a legitimately intellectual job back in the day!
        
         | thaumasiotes wrote:
         | > Blacksmiths had a legitimately intellectual job back in the
         | day!
         | 
         | ACOUP noted that blacksmiths might be assisted by unskilled
         | laborers, strikers, who had the actual job of lifting the
         | hammer and hitting the object with it.
        
           | NegativeLatency wrote:
           | Unskilled feels unfair, it requires a fair bit of skill, and
           | you're also learning how to forge while doing it.
        
             | droopyEyelids wrote:
             | This has been such a frustrating culture war definitional
             | argument.
        
               | knodi123 wrote:
               | Not necessarily a culture war thing. People who aren't
               | familiar with the subject might take "unskilled" in the
               | plain-english sense, as a pejorative. And who can blame
               | them? We're english speakers before we're technical
               | speakers.
               | 
               | Make gracious assumptions.
        
             | bell-cot wrote:
             | The reality is that, depending on circumstances, a highly
             | skilled craftsman of yesteryear could have any number of
             | obviously less-skilled assistants. Some would be "career
             | track", some semi-skilled seasonal help, some minimally-
             | skilled (whether due to youth, infrequent day labor, poor
             | talent, or social status), and some in supporting type of
             | skilled work - animal handling, cooking, bookkeeping, etc.
        
             | Terr_ wrote:
             | I tried to maintain a certain kind of optimistic humility,
             | that almost anything which employs a person full-time is a
             | problem-area that has fractal layers of complexity one
             | don't have to know from the outside.
             | 
             | The only question is whether someone will pay you for doing
             | the fancy skill/science tricks or not.
        
             | thaumasiotes wrote:
             | > Unskilled feels unfair, it requires a fair bit of skill,
             | and you're also learning how to forge while doing it.
             | 
             | Both of those points are untrue. Strikers are unskilled
             | labor and in general are not learning how to forge. The
             | smith shows where he wants the hammer to fall, and they let
             | it fall there.
             | 
             | https://acoup.blog/2020/10/02/collections-iron-how-did-
             | they-...
             | 
             | > Things were worse for the many strikers and other
             | laborers who were essentially unskilled hired hands or even
             | enslaved laborers (given their depiction in artwork, it
             | seems likely many ancient strikers were slaves) of much
             | lower status and who could not expect to be trained into
             | blacksmiths themselves some day. While some strikers were
             | probably apprentices in training, it is quite clear that
             | not all of them were! These workers would also have been
             | far less richly paid; _indeed, the entire point of strikers
             | was to have laborers who could be paid very little but
             | still amplify the production ability of the blacksmith
             | himself._
             | 
             | (emphasis original)
        
         | HPsquared wrote:
         | This effect also applies to polymers! Perhaps even more so.
         | Take a polyethylene bag (LDPE) and stretch the material in one
         | direction. You might notice the material becomes thinner but
         | also stronger. This is due to the polymer chains becoming
         | aligned. Eventually you get "drawn fibers" where the molecular
         | strands are aligned with the fibers for optimum tensile
         | strength.
        
           | 01HNNWZ0MV43FF wrote:
           | That makes sense, if I don't rip open a bag on the first try
           | it'll just stretch and never open
        
           | kragen wrote:
           | it varies a lot with polymers, and it's a different effect.
           | steel is entirely crystalline; ldpe is mostly amorphous. a
           | big part of what's happening in the strain hardening of ldpe,
           | aside from making it uniaxially oriented, is that it's
           | crystallizing; the crystalline domains become larger, greatly
           | reducing the amorphous volume fraction. (there are also other
           | ways of achieving this effect, such as annealing, which you
           | will notice softens steel rather than hardening it.) ldpe's
           | strength isn't determined by crystal dislocation density in
           | the same way as steel's, and of course steel doesn't have
           | polymer chains to align
        
         | pfdietz wrote:
         | I wonder if it's possible to do additive manufacturing with
         | pre-elongated snippets of wire.
        
         | kragen wrote:
         | > _just squishing steel does NOT make it stronger_
         | 
         | just squishing steel does actually make it stronger, because it
         | increases the number of dislocations in its crystal structure.
         | smaller grains mean higher strength even without the variable
         | grain direction. also, peening, which is not exactly the same
         | as forging but is also just squishing steel, can give you
         | higher strength for a third reason: areas with residual
         | compressive stress can't initiate cracks until you overcome
         | that stress, which increases strength. even more, though, it
         | increases fatigue resistance
        
         | samstave wrote:
         | I have had this question in my mind for decades:
         | 
         | > _" Can you forge metals in a highly controlled and directed
         | magnetic field where you can orient the grain/alignment of
         | atoms/fields in whatever direction you want. Further, if true,
         | what happens when you make damascus from varying plated that
         | have particular alignments/grains - and what are the features
         | of this material?_
        
       | Yenrabbit wrote:
       | For a program started in the 50s, it's impressive that "Six of
       | the ten presses are still operational today."!
        
         | barryp wrote:
         | I got curious as what happened to the other 4. Wikipedia lists
         | them as extrusion presses being scrapped in the 90's and 2021
         | in Maryland and Torrence CA.
         | https://en.wikipedia.org/wiki/Heavy_Press_Program
         | 
         | I wonder if they wore out?, something better came along?, or
         | just no demand?
        
           | SoftTalker wrote:
           | They've been maintained, wear parts such as bearings and
           | seals can be replaced. You can keep well-made machinery
           | running almost indefinitely if you take care of it.
        
       | bhouston wrote:
       | More details in this video:
       | https://www.youtube.com/watch?v=iZ50nZU3oG8
        
       | chasil wrote:
       | I understand that this press, and the Cleveland site, is now
       | owned by Howmet Aerospace, which is a "daughter company" of Alcoa
       | (along with Arconic) after its 2020 separation.
       | 
       | https://en.wikipedia.org/wiki/Howmet_Aerospace
       | 
       | The big Cleveland press has its own wiki.
       | 
       | https://en.wikipedia.org/wiki/Alcoa_50,000_ton_forging_press
        
         | a2tech wrote:
         | Howmet is an interesting company. My dad worked for them his
         | entire life (it was called MISCO, then Howmet bought them, then
         | Alcoa). He worked specifically in titanium injection molding--
         | they would heat titanium until it was liquid and then force it
         | under pressure into intricate molds they made onsite.
         | 
         | Most of the time they made turbine blades for jet engines, but
         | if it was slow they would make golf club heads for PING and
         | companies like that. In all the years he worked there, the golf
         | club heads were the only tangible product of his work that I
         | saw because everything else was tightly controlled in the
         | facility.
        
           | chasil wrote:
           | The blades were actually perfect crystals, with either all
           | the grain boundaries aligned, or no grain boundaries. This
           | lets them run at higher temperatures without melting,
           | increasing efficiency.
           | 
           | Pratt & Whitney appears to have developed most of the
           | technology.
           | 
           | https://www.americanscientist.org/article/each-blade-a-
           | singl...
        
             | dekhn wrote:
             | Oh, so that's what they were doing in the facility in my
             | hometown. It was always pretty secretive and now I can see
             | why.
        
       | baking wrote:
       | There is no "H" in "Worcester."
        
         | mhb wrote:
         | And it's odd to see one there, since, from the pronunciation,
         | you'd expect it to be spelled "Wooster".
        
           | mauvehaus wrote:
           | The Wooster in Ohio is spelled "Wooster".
        
       | shepherdjerred wrote:
       | What strikes me is how great of an investment this turned out to
       | be. Does the US invest in manufacturing like this anymore?
       | 
       | Tangentially, if there were a war today would the US be able to
       | produce as much as it did in WW2?
        
         | bradford wrote:
         | > Does the US invest in manufacturing like this anymore?
         | 
         | It might be easy to argue over the exact degree of similiarity,
         | but I'd argue that the US has repeatedly made manufacturing
         | investments since the 1950s. Buried in bills signed into law,
         | you'll find such investments.
         | 
         | Recent examples include the Recovery Act of 2009 or the
         | American CHIPS act of 2022.
         | 
         | https://en.wikipedia.org/wiki/American_Recovery_and_Reinvest...
         | 
         | https://www.cfr.org/in-brief/what-chips-act
        
         | waythenewsgoes wrote:
         | In terms of raw output, the answer is likely no.
         | 
         | However, this might not matter as much now as it did in the
         | past due to nuclear weapons being the primary deterrent in war
         | these days, and the fact that our standing fleet of aircraft,
         | aircraft carriers, nuke subs, tanks, etc... is essentially
         | second to none. Additionally what we do have is highly capable
         | and extremely specialized, in my opinion, leading to not really
         | needing as many (quality over quantity). Take for example, an
         | F35, which doesn't really have an equal in the skies, we have
         | over 630 of them, with the goal of having around 2500. China
         | only has 300 J-20s which are basically a copy of the older F22.
         | Russia only has 22 non-test Su-57s. Would we have a realistic
         | need to build 1000 of them within a year?
         | 
         | Due to many factors, but primarily free trade and
         | globalization, it's unlikely that we ever see that non-
         | automated manufacturing capacity return, though if needed we
         | could probably mobilize the economy via the defense act to
         | force more manufacturing capacity, though it's hard to imagine
         | we would currently need to.
        
         | bluGill wrote:
         | > Does the US invest in manufacturing like this anymore?
         | 
         | No, but that is different from not investing. Today the US
         | invests more in automation and engineering and less in manual
         | labor.
         | 
         | > if there were a war today would the US be able to produce as
         | much as it did in WW2?
         | 
         | It took several years to ramp up to WW2 level production. We
         | would see the same, a couple years of trouble on the fronts
         | while building industry at home, then when the industry is
         | built up massive production.
         | 
         | Historians (amateur so I'm not sure if they are right) tell me
         | Hitler was ready for WW2 first and Italy begged him to not
         | start the war as their industry wasn't ready. However France
         | and Briton saw the war coming and were building their industry
         | and so waiting might have made things worse.
        
         | margalabargala wrote:
         | We didn't have _any_ of these presses in WWII. We have several
         | of the article 's presses still operating today.
         | 
         | Furthermore, all presses mentioned in the article have been
         | surpassed by a 60,000 ton press that opened in Los Angeles, in
         | 2018.
         | 
         | People with agendas will happily feed others narratives about
         | the US not investing in manufacturing anymore, but it isn't
         | true.
         | 
         | US manufacturing output has been steadily increasing since
         | always, with the occasional 1-3 year dip during recessions.
         | However, manufacturing does represent a lower percentage of our
         | GDP with each passing year, despite the absolute value
         | increasing.
        
       | wyck wrote:
       | Some machine porn I found about the the biggest(?) press in the
       | world in L.A. by Weber metals, I think it's 60k tons.
       | https://www.youtube.com/watch?v=mOe8KYZXGeg
        
       | gffrd wrote:
       | > By the early 2000s, parts from the heavy presses were in every
       | U.S. military aircraft in service, and every airplane built by
       | Airbus and Boeing.
       | 
       | >The savings on a heavy bomber was estimated to be even greater,
       | around 5-10% of its total cost; savings on the B-52 alone were
       | estimated to be greater than the entire cost of the Heavy Press
       | Program.
       | 
       | These are wild stats.
       | 
       | Great article! I was fascinated to learn about the Heavy Press
       | program for the first time, here on HN[1] a month ago, and am
       | glad more about it is being posted.
       | 
       | It makes me think: what other processes could redefine an
       | industry or way of thinking/designing if taken a step further? We
       | had forging and extrusion presses ... but huge, high pressure
       | ones changed the game entirely.
        
         | westurner wrote:
         | > _It makes me think: what other processes could redefine an
         | industry or way of thinking /designing if taken a step further_
         | 
         | Pressure-injection molded hemp plastic certainly meets spec for
         | automotive and aerospace applications.
         | 
         | "Plant-based epoxy enables recyclable carbon fiber" (2022)
         | [that's stronger than steel and lighter than fiberglass]
         | https://news.ycombinator.com/item?id=30138954 ...
         | https://news.ycombinator.com/item?id=37560244
         | 
         | Silica aerogels are dermally abrasive. Applications for non-
         | silica aerogels - for example hemp aerogels - include thermal
         | insulation, packaging, maybe upholstery fill.
         | 
         | There's a new method to remove oxygen from Titanium: "Cheap yet
         | ultrapure titanium metal might enable widespread use in
         | industry" (2024) https://news.ycombinator.com/item?id=40768549
         | 
         | "Electric recycling of Portland cement at scale" (2024)
         | https://www.nature.com/articles/s41586-024-07338-8 ...
         | "Combined cement and steel recycling could cut CO2 emissions"
         | https://news.ycombinator.com/item?id=40452946
         | 
         | "Researchers create green steel from toxic [aluminum production
         | waste] red mud in 10 minutes" (2024)
         | https://newatlas.com/materials/toxic-baulxite-residue-alumin...
         | 
         | There are many new imaging methods for quality inspection of
         | steel and other metals and alloys, and biocomposites.
         | 
         | "Seeding steel frames brings destroyed coral reefs back to
         | life" (2024) https://news.ycombinator.com/item?id=39735205
        
       | nickdothutton wrote:
       | These massive presses are/were of strategic importance. Something
       | politicians, most of whom seem to be lawyers these days,
       | completely fail to grasp. I am not in general a fan of government
       | subsidy, but I was very disappointed when the government of the
       | UK declined to fund a large press in Sheffield, which would have
       | been used to build the next generation of nuclear reactors. June
       | 2010 timeframe. Luckily natural gas is cheap and has no
       | geopolitical supply chain problems eh?
        
         | Dennip wrote:
         | Sheffield Forgemasters?
         | 
         | They are actually now directly govt owned as of 2020, with
         | future investment for a new heavy forge.
        
       | ckemere wrote:
       | Was reading this NYT op ed -
       | https://www.nytimes.com/2024/08/19/opinion/chris-murphy-demo... -
       | and reflecting that the people talking don't get that the secret
       | sauce for meaningful labor is not just that it pays, but also the
       | sense that it is "special" somehow, in the sense that
       | manufacturing parts with 50000 ton press is manual labor but also
       | remarkable because of the uniqueness of the machine being used.
       | 
       | Most discussions about trying to build industrial capacity in the
       | US seem to focus on either our high labor costs or on the
       | disinterest in capital to invest in low margin places. I would
       | love to understand what time frame of guaranteed business the
       | government provided these companies to convince them to
       | participate, and also what other industrial processes the
       | government invested in which failed to take off. Specifically,
       | why didn't this sort of thing work for the solar industry a few
       | years back?
        
       | Animats wrote:
       | Progress continues. The biggest press in the world today was
       | built in 2018, is rated for 60,000 tons, and is in Los Angeles
       | County, California.[1][2]
       | 
       | [1] https://www.lightmetalage.com/news/industry-
       | news/forging/web...
       | 
       | [2] https://www.youtube.com/watch?v=jNFIMy8BuHc
        
         | doormatt wrote:
         | The article says there's an 80,000 ton press in China.
        
           | kragen wrote:
           | many people in the usa say 'the world' when they mean 'usa'
        
             | retzkek wrote:
             | That's pretty ungenerous. The press release says "The press
             | is the world's strongest hydraulic pull-down die forging
             | press in pit-mounted design" so it's easy for a layman to
             | read "world's strongest ... press" and take that at face
             | value.
        
       | brcmthrowaway wrote:
       | Is this how the SR71 was made?
        
       | advisedwang wrote:
       | This should be a lesson for free-market advocates, especially
       | those who see the US economic boom as a result of laissez-faire
       | economics. In reality there are opportunities the free market
       | doesn't take, and wise government intervention can yield enormous
       | benefit to the public.
        
         | mannyv wrote:
         | In reality what we call 'capitalism' is unstable and requires
         | continual intervention to survive.
        
       | azalemeth wrote:
       | If you're reading this article, you may wish to know that
       | arguably a "counterpart" to heavy press forging is explosive
       | forming [1] in which a chemical high explosive is used to force a
       | template material against a template. The overpressure generated
       | by the explosive can be equivalent or maybe even greater than
       | heavy press forgings (a 50,000 US short ton force press exerts
       | [?]500 MN force; peak overpressure close to detonating TNT or
       | PETN explosives can be MPa or higher [2] so depending on the
       | geometry of the part they may be comparable) and it has the added
       | "fun" fact that complex cylindrical or spherical shapes can be
       | made very easily and accurately.
       | 
       | The only people I know who have worked with this have used it to
       | make superconducting magnets, explosively forming either titanium
       | or high grades of nonmagnetic stainless (A4, which has ur [?] 1)
       | without causing marsenite formation due to machining. This
       | includes a major international MRI scanner manufacturer, for one
       | relatively niche product. It's like the "extreme" version of
       | metal spinning [3] - forcing a rotating chunk of metal against a
       | rotationally symmetric mandrel.
       | 
       | [1] https://en.wikipedia.org/wiki/Explosive_forming [2]
       | https://www.researchgate.net/figure/Variation-of-peak-over-p...
       | [3] https://en.wikipedia.org/wiki/Metal_spinning
        
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