You are not logged in.
I will be brief, as I like what you guys are doing here. My little thought is that it may be possible to review ancient iron and steel work, to perhaps size an early steel making industry, to the limited means that will be available at first. This one is about the Roman era, but also we could look all over the world for how these things might have been done on the small scale: https://dtrinkle.matse.illinois.edu/Mat … ce_an.html
Quote:
Steel in Ancient Greece and Rome
What interested me is how they could do the process with a lower heat level.
Quote:
Smelting
The melting point of pure iron is 1540°C. Landels points that even by Roman times European furnaces were not producing heat much over 1100°C[9]. Smelting of iron, unlike the smelting of the lower melting point metals, copper, zinc and tin, did not involve the iron turning to the liquid state. Instead, it was a solid state conversion requiring chemical reduction of the ore. Ore was placed in a pit and mixed in a hot charcoal fire. Air was forced into the dome covered structure via bellows through a fireproof clay nozzle called a tuyere. After a sustained temperature of 1100°-1200°C, slag (oxidised non-metallics) fell to the bottom leaving the spongy mass containing the iron. Holes forming the sponge texture were a result of the removal of the non-metallics when the slag melted out. The spongy mass is called a bloom by some[10, 11]. This spongy mass was then pounded, usually while still hot, and more slag dropped out as the metal was concentrated into a denser mass. The pounded metal was called wrought iron.
Aitchison gives a mean composition of a typical bloom but this could vary widely, depending especially on the origin of the ore;Carbon 0.097%
Silicon 0.046%
Manganese 0.040%
Sulphur 0.025%
Phosphorous 0.044%
Arsenic 0.049%
Copper 0.010%
Iron remainder
My thinking is that unlike present day Earth on Mars, there will be much less industrial support, at first, so small batches may have a place.
Done
Last edited by Void (2024-02-08 11:07:26)
Done.
Offline
Calliban,
Mangalloy is going to be a pain to work with, but we already do work with it here on Earth, so obviously it can be done. People make swords and knives with the stuff in their home workshops. My understanding, which may be incorrect, is that the work-hardening mostly occurs to the surface of the material when subjected to impact or other high-stress mechanical loads, and that it responds the opposite of how you'd expect normal steels to behave. Quenching, which is normally associated with hardening of Carbon steel alloys, actually softens Mangalloy. That means dunking the work piece in a cryogen tank, or simply filling a cylindrical Mangalloy pressure vessel tank with cryogenic liquid, will make a previously work-hardened piece softer again. Grinding is not impossible, but you need very hard grinding wheels. You can cut through this stuff with a hacksaw, but it will take a lot of time and lubricant. I've seen numerous videos of high-Manganese steel being cut with lasers or plasma cutters or torches. There are other videos of people CNC machining it.
The real issue is whether or not the material survives the cold acceptably well so we don't absolutely require specialized stainless steels that will be even more difficult to source ores for and more energy-intensive to produce. If Mars was loaded with Nickel and Chromium, then I'd advocate for using stainless. I figure we're going to hot roll plates of this stuff, as is apparently done here on Earth, cut them to length with a plasma torch, roll them into cylindrical pressure vessels while they're still warm, and then weld them together. We must have deep-cold / radiation-protected living spaces, "tiny homes" which closely resemble large Propane tanks, that we can then bury just below the surface of the regolith, or heap regolith on top of. If we can do that, and source the water, then we have long-term guaranteed environmental protection for the colonists.
I agree that casting every bit of metal we make is not very practical, and likely impossible. I never suggested we try to substitute castings where only sheet or plate steel will do, merely that making 20 different thicknesses of plate or sheet for some specialty use case is equally impractical with limited machinery and energy input. I meant to suggest that if we need pipe fittings or valve bodies, as I think we will, then we require decent castings that can survive the nights on Mars.
Offline
This sounds interesting but I will want more details: https://www.msn.com/en-us/money/other/s … r-BB1hUzeK Quote:
Scientists just turned toxic red mud into CO2-free iron — here's how
Story by Can Emir •
1d
Done
Last edited by Void (2024-02-08 13:05:57)
Done.
Offline
According to the wiki article: https://en.m.wikipedia.org/wiki/Mangalloy
'Alloys with manganese contents ranging from 12 to 30% are able to resist the brittle effects of cold, sometimes to temperatures in the range of −196 °F (−127 °C).'
Also from wiki: https://en.m.wikipedia.org/wiki/Climate_of_Mars
'Differing in situ values have been reported for the average temperature on Mars,[23] with a common value being −63 °C (210 K; −81 °F).[24][25] Surface temperatures may reach a high of about 20 °C (293 K; 68 °F) at noon, at the equator, and a low of about −153 °C (120 K; −243 °F) at the poles.[26] Actual temperature measurements at the Viking landers' site range from −17.2 °C (256.0 K; 1.0 °F) to −107 °C (166 K; −161 °F). The warmest soil temperature estimated by the Viking Orbiter was 27 °C (300 K; 81 °F).[27] The Spirit rover recorded a maximum daytime air temperature in the shade of 35 °C (308 K; 95 °F), and regularly recorded temperatures well above 0 °C (273 K; 32 °F), except in winter.[28]'
So I think manganese steels can be made that retain ductile properties in most locations on Mars except the poles. In the polar regions in winter, exposed structures and vehicles may need to be aluminium framed. Everywhere else, manganese steels will remain ductile.
Last edited by Calliban (2024-02-08 15:05:54)
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
Offline
Looking to the past is definitely worthwhile. Ulfberht swords were made by Vikings in the 9th to 11th centuries (800s to 1000s). Vikings had a trade route along the Volga and Dnieper rivers to Constantinople, Jerusalem, Baghdad, and the Caspian Sea, and the end of the Silk Road. (Wikipedia) They traded with Arabs. Vikings acquired a block of crucible steel. That was made by placing bloomery iron (a bloom) in a ceramic crucible with cullet (scrap glass) on top. The crucible was placed in a single-use furnace made of clay brick, and the bricks sealed with wet clay. Inside the furnace was charcoal. A pair of bellows provided constant forced air flow through the burning charcoal. The wet clay would quickly dry and harden. Temperature had to reach a sufficient temperature to completely melt the bloom, and had to be maintained for a certain number of hours. Workers would take turns operating the bellows. One modern recreating showed bellows operated by foot, with one bellows pushed down while the other is opening up. The cullet would bind with impurities of the bloom, which would settle out of the steel. After maintaining high temperature for a specific number of hours, the brick furnace was dismantled. The crucible was removed with tongs, still glowing red hot. A hammer would smash the ceramic crucible off the block of steel. The cullet would form a layer of glass on top of the steel, which would be smashed off as well. The final result is a block of very pure steel. Modern recreations have been analyzed, compared to steel from a modern steel mill. The steel mill operator was very impressed, it was almost as pure as modern steel.
This block of steel will have a very tight grain, with steel grains intertwined to create a hard block that is not ductile. A smith must heat the block of steel red hot, then carefully hammer it to break the grain, cause the steel to move. This can result in cracking the block, which would ruin it. There are many steps in creating an Ulfberht sword where a single mistake will ruin the whole thing. But after carefully breaking the grain without cracking the block, the block can be formed like any other steel.
An Ulfberht sword is pattern welded. In period it was made with 50% crucible steel, 50% bloom. A modern sword would use mild steel instead of bloom. Forge weld a rod of crucible steel with an equal size rod of bloom. Then twist it. Make 3 rods this way, the centre rod twisted in the opposite direction. The twisted rods are hammered to have flat sides so they can be forge welded together, side-by-side. The centre rod is longer because it forms the tang and sword tip. Then a strip of crucible steel was forge welded along each side, with the two strips meeting at the point of the sword. The smith then hammers this into shape, forming a cutting edge of the side strips and tip. A "blood groove" was also hammered down the centre on both sides. This isn't for blood, it's to reduce weight. After the shape is complete, it's heated and quenched to harden. Then the sword edges are ground razor sharp. Apply quillon (cross guard), handle and pommel before sharpening.
Before hardening, an Ulfberht sword had the name "+VLFBERHT+" or "+VLFBERH+T" carved into the blade near the quillion, and steel inlay placed, hammered in, then ground flat with the blade of the sword. Obviously the process of inlay could ruin the sword, but the name greatly increased the sword's price.
Pattern welding of high purity high carbon steel with iron resulting in a tough blade. The hardness of the high carbon steel held a cutting edge well, but could be brittle. The bloomery iron was soft but tough, so it wouldn't break. When the blade is polished and acid etched, the twisted metal forms a herringbone pattern. And the acid etching makes the inlay name visible.
I mention this because it's a small scale way to make high purity, high carbon steel. But modern methods should work even better. We should be able to adapt a modern steel smelter to small scale.
Reference on YouTube: PBS NOVA 2017 Secrets of the Viking Sword (1 hour long)
another YouTube video. This one doesn't use cullet, but seals the crucible with clay, using soft clay to form an air-tight seal between crucible and clay cap. The reason for sealing the crucible is to ensure CO2 and CO from burning charcoal of the furnace doesn't not absorb into the steel. This could add too much carbon, making the steel brittle. But a measured quantity of charcoal is added to the crucible before sealing it. To make high carbon steel, but with just the right amount of carbon. Ulfberht Viking Sword - MAN AT ARMS:REFORGED (19 minutes 14 seconds long)
Offline
This may be of interest for methods for Mars for Steel: https://www.youtube.com/watch?v=QwtQS146tak
Quote:
Green Hydrogen making Green Steel. Is 2024 the breakthrough year?
Just Have a Think
So, maybe useful.
Done
Last edited by Void (2024-02-18 22:07:44)
Done.
Offline
A useful technology for pig iron production is the rotating kiln.
https://en.m.wikipedia.org/wiki/Rotary_kiln
This device is a steady flow process. Iron oxide enters at one end of the kiln. It is reduced to a mixture of molten pig iron and silicate slag. This allows a relatively compact device to convert iron ore into crude iron for casting. On Mars, there is abundant iron rich sand which could be used as feedstock for this type of kiln without need for milling. Carbon would be added to the ore to reduce the melting point of the iron to 1200°C. Hydrogen or CO could be used as reducing gas. The pig iron emerging from the kiln could be directly cast into products, like the iron struts needed for geodesic domes. The crude pig iron will be relatively brittle due to impurities. But this is less problematic if it is used for compressive structural elements.
Later in the colonisation programme, high carbon pig iron could be drained into an electric arc or induction furnace, where impurities will be removed and steel can be produced.
Last edited by Calliban (2024-02-23 05:25:51)
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
Offline
An interesting article on the assessment of historical structures made from cast iron, wrought iron and steel.
https://www.buildingconservation.com/ar … onwork.htm
Wiki article here: https://en.m.wikipedia.org/wiki/Gray_iron
Cast irons have superior compressive strength to low alloy steels and wrought iron. In theory, a perfect specimen would have greater tensile strength as well. But grey iron is brittle and graphite flakes can propagate cracks, so allowable tensile stresses are lower. Grey cast iron can be used in tensile members and for structures constructed before about 1870, this was common. But the need for additional design factors makes it an inefficient solution. As wrought iron became more widely available, it displaced cast iron in tensile structures. Wrought iron members can be lighter and stresses can be higher, due to its ductility. Wrought iron has similar strength and ductility to mild steel, but tends to be more fibrous.
Gray cast irons remain in use in some old structures in the UK. Grey cast irons do have some structural advantages over steels within their limitations. In structures where stresses are predominantly compressive, cast iron is still used. One advantage that grey iron has is low melting point compared to mild steel. Cast iron can melt at temperatures as low as 1150°C. This allows use of sand castings, which would be plausible for mild steel because the melting point of pure iron is too high. It also makes cast irons easily weldable. As the forces acting on the structural members of geodesic domes are mainly compressive, grey cast iron is definitely something we can use.
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
Offline
For Calliban re recent contributions to this topic ...
While we wait for an Industry index level, this topic seems to be working as a place for you to develop your ideas for a cast iron geodesic dome business concept. I'm hoping you are on a roll here, and that a few words of encouragement will be helpful to keep your ideas flowing.
You could approach this as a vertically integrated industry, and then spin off divisions as they become large enough.
It seems to me (as a first pass at trying to envision this industry) that you will need divisions for Architecture, Mining, Refining, Forming, Storage, Distribution, Assembly, Marketing and the all-important Sales.
(th)
Offline
I think the members could be interested, I think Martian dune materials might be processed this way: https://journals.plos.org/plosone/artic … ne.0249962
Quote:
Iron can be microbially extracted from Lunar and Martian regolith simulants and 3D printed into tough structural materials
Sofie M. Castelein ,Tom F. Aarts ,Juergen Schleppi,Ruud Hendrikx,Amarante J. Böttger,Dominik Benz,Maude Marechal,Advenit Makaya,Stan J. J. Brouns,Martin Schwentenwein,Anne S. Meyer ,Benjamin A. E. Lehner
Published: April 28, 2021
And the 3D printing is of interest also for making parts.
Done
Last edited by Void (2024-03-10 10:56:38)
Done.
Offline
Don’t believe the spin: coal is no longer essential to produce steel
Offline