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ARCH 1764 Under the Microscope 250 Years of Brown’s Material Past

Prof. Clyde Bryant Office hours Wednesday 4:00-6:00 pm 220 Barus and Holley

Prof. Brett Kaufman Office Hours: Tuesdays, 2:00-4:00 pm Rhode Island Hall 007

TA Susan Herringer

This presentation and the images within are for educational purposes only, and are not to be distributed Ferrous Metals and STEEL Ferrous Metals

• All iron-based • Steel is Fe-C with less than 0.8% C • Cast are Fe-C with 2-5 % Fe-C Phase Diagram Types of Steel

• Low Alloy – carbon below 0.8%; usually contain Mn, Ni, Si, Cr • Eutectoid Steels – 0.8% Carbon; is the main constituent • Stainless Steels – High Ni and Cr; Carbon less than 0.1%; some are non-magnetic Carbides in Steel Pearlite Gray Cast Iron

• Contains above 2% Si and has in flake-like form • Because graphite has little strength it tends to be very brittle. • Very good damping characteristics http://core.materials.ac.uk/sea rch/detail.php?id=1416

http://www.heunisch- guss.com/en/products/grey -cast-iron.html http://www.ygic.com.tw/elist4_1.htm White Cast Irons

• Less than 1% Silicon • Extremely hard and durable • Wear resistant http://www.ssplprints.com/image/129622/hyp er-eutectic-white-cast-iron-typical-ana Cost Factors

Large plants vs. mini-mills Politics of mining Making Steel

• https://www.youtube.com/watch?v=9l7Jqony oKA Refining Steel

• Use slag to reduce impurities • Impurities can cause brittleness • Today phosphorus and sulfur kept below 0.01%

Tempering of Steel

http://cr4.globalspec.com/blogentry/14219/40 -Carbon-Steel-Brinell-Hardness-vs-Tempering- Temperature Glossary Occurrence Chronology Microstructures of ancient and ancient ferrous alloys Reconstruction of Medieval crucible steel smelting Glossary of technical terms Wrought iron: Pure iron produced in the bloomery process, with a microstucture known as ferrite Cast iron: Iron that solidifies from molten state : Extraterrestrial iron, often with a high (between 5-20 wt% Ni) content conferring hardness and corrosion resistance, with characteristic widmänsttaten structure. Telluric iron: Native iron from , less than 5 wt% nickel Bloom: An iron mass with ore, slag, and furnace environment impurities that is the intermediate product between smelting an ore and a finished product. Forging: When a bloom or iron mass is hammered into an ingot or billet Smithing: Hammering and shaping of ingot or billet into finished product. Hammerscales: The detritus that flies off during hammering Slag: The undesired mixture of gangue, flux, and metallurgical debris Flux: chemical mixtures that bond with gangue materials to make a slag flow Steel: Iron with a carbon content under 2.1 wt%, with phases such as pearlite, austenite, martensite

Hammerscales recovered with a widmänsttaten magnet from excavations structure

http://www.daviddarling.info/encyclopedia/W/Widmanstatten_pattern.html Iron makes up about 5% of the earth’s crust, and the core of the earth is an iron-nickel mass which gives it magnetic properties and keeps it in orbit.

http://www.wired.co.uk/news/archive/2013-10/13/core-blimey Native iron Telluric

Greenland

http://www.mindat.org/loc-1964.html , telluric iron mass Native iron Egyptian bia’ n pet “iron from heaven” Meteoric Hittite AN.BAR GE6 “black iron of heaven” Persian “lightning iron”

http://scribol.com/science/7-most-massive-single-meteorites-on-earth

Meteoric iron “tent” from Cape York, Greenland weighing in at 31 tons Iron ores: Oxides: Hematite, Goethite, , Ochre Sulfides: Pyrite, Pyrrhotite

http://en.wikipedia.org/wiki/Goethite Goethite on quartz Copper smelting is what lead to the discovery of iron smelting, and this occurred due to the following scenarios:

1) Reduction of the copper oxides and carbonates, such as malachite and azurite, are aided by the addition of as a flux in the furnace either from the flux or the iron content of the copper ore (Wertime 1980; Wheeler and Maddin 1980). It would not take long for ancient smiths to see that after slagging, small iron blooms would be inadvertently created and left in the furnace (Wertime 1980; Wheeler and Maddin 1980). 2) Once the oxidized gossan of copper surface deposits was fully exploited, only the sulfidic ores remained. This could often include substantial iron concentrations, such as in chalcopyrite. Smelting of this ore would likely also leave unmelted iron and matte in the hearth or furnace (Craddock 1995, 149-153). 3) Recent work has also suggested that iron played a role not only in early copper production, but also in early arsenical copper production (Thornton, Rehren, and Pigott 2009). Iron arsenide ore, or speiss, was likely recognized as a special alloying component to be mixed with pure molten copper, or perhaps co-smelted to produce an arsenical bronze. Iron byproducts would have been produced in this way as well, as seen at Tepe Hissar in Iran by the 4th millennium BC (Thornton and Rehren 2009).

Chronology ►Makapansgat Pebble – iron oxide based jasperite artifact, perhaps the oldest manuport discovered. Associated with Australopithecus africanus around 3 million years ago in South Africa. ► By 300,000 years ago there is firm evidence for the use of ochre (iron oxide) by Homo erectus in a deposit of dozens of ochre artifacts in an Acheulean context, Terra Amata, France. ► Neanderthals used hematite and goethite iron ores for pigments stored in perforated scallop shell 50,000 years ago at Cueva Antón, Spain.

► From 5000 BC until the Iron Age there are dozens of scattered iron finds throughout Mesopotamia, Anatolia, Egypt and the Levant, as well as Cyprus and Crete.

Chronology 1200 BC – Iron Age begins in Eastern Mediterranean 1000-900 BC – iron replaces copper as major metal 800-400 BC – Cast iron invented in China 1000-1500 AD – cast iron gradually adopted in Europe throughout Middle Ages and Renaissance 1855 AD – Bessemer Process, where oxygen was forced through iron, leading to combustion and incredible purity of the iron. Higher carbon cast or pig iron could then be mixed in to control carbon content.

Bessemer 1905 Different types of iron/steel blades found on artifacts

Tylecote and Gilmour 1986 Crusader steel ship nail, ~1225 AD Slag stringers

Equi-axied Ferrite grains

Weld

Enlarged ferrite grains with pearlite clusters Mineralized pearlite clusters in fully corroded Carthaginian steel implement, 550-500 BC Crucible steel Wootz high-carbon steel ingot from Deccan region of India, 18th century AD Clean iron microstructure with no slag, white needles and dark brown pearlite zones

Scott 2014 Han Dynasty sword blade from Gansu Province, China Finely laminated structure is result of repeated folding and working of hypoeutectoid steel, with white bands of copper or nickel enrichment zones

Scott 2014 https://www.youtube.com/watch?v=nXbLyVpWsVM References

Bessemer, Henry. 1905/1989. Sir Henry Bessemer, F.R.S.: An Autobiography. London: The Institute of Metals. Boyd, Robert, and Joan B. Silk. 2012. How Humans Evolved, Sixth Edition. New York and London: W.W. Norton & Company. Craddock, P. T. 1995. Early Metal Mining and Production. Washington, D.C.: Smithsonian Institution Press. Oakley, K.P. 1981. Emergence of Higher Thought 3.0-0.2 Ma B.P. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences 292 (1057 The Emergence of Man):205-211. Schmandt-Besserat, Denise. 1980. Ocher in Prehistory: 300,000 Years of the Use of Iron Ores as Pigments. In The Coming of the Age of Iron, edited by T. A. Wertime and J. D. Muhly. New Haven and London: Yale University Press. Scott, D.A. 2014. Metallography and Microstructure of Metallic Artifacts. In Archaeometallurgy in Global Perspective: Methods and Syntheses, edited by B. W. Roberts and C. P. Thornton: Springer. Thornton, C. P., and T. Rehren. 2009. A Truly Refractory Crucible from Fourth Millennium Tepe Hissar, Northeast Iran. Journal of Archaeological Science 36 (12):2700-2712. Thornton, C. P., Th Rehren, and V. C. Pigott. 2009. The Production of Speiss (Iron Arsenide) during the Early Bronze Age in Iran. Journal of Archaeological Science 36 (2):308-316. Tylecote, R.F., and B.J.J. Gilmour. 1986. The Metallography of Early Ferrous Edge Tools and Edged Weapons. Vol. 155. Oxford: B.A.R. British Series. Waldbaum, Jane C. 1980. The First Archaeological Appearance of Iron and the Transition to the Iron Age. In The Coming of the Age of Iron, edited by T. A. Wertime and J. D. Muhly. New Haven and London: Yale University Press. Wertime, Theodore A. 1980. The Pyrotechnological Background. In The Coming of the Age of Iron, edited by T. A. Wertime and J. D. Muhly. New Haven: Yale University Press. Wheeler, T.S., and R. Maddin. 1980. Metallurgy and Ancient Man. In The Coming of the Age of Iron, edited by T. A. Wertime and J. D. Muhly. New Haven: Yale University Press. Zavada, Michael S., and Ann Cadman. 1993. Palynological Investigations at the Makapansgat Limeworks: an Australopithecine Site. Journal of Human Evolution 25 (5):337-350. Zilhão, João, Diego E. Angelucci, Ernestina Badal-García, d'Errico Francesco, Floréal Daniel, Laure Dayet, Katerina Douka, Thomas F.G. Higham, María José Martínez-Sánchez, Ricardo Montes-Bernárdez, Sonia Murcia-Mascarós, Carmen Pérez-Sirvent, Clodoaldo Roldán-García, Marian Vanhaeren, Valentín Villaverde, Rachel Wood, and Josefina Zapata. 2012. Symbolic Use of Marine Shells and Pigments by Iberian Neanderthals. Proceedings of the National Academy of Sciences 107 (3):1023-1028.