Editing Quenching (section)

== History ==
There is evidence of the use of quenching processes by blacksmiths stretching back into the middle of the [[Iron Age]], but little detailed information exists related to the development of these techniques and the procedures employed by early smiths.<ref name=":2">{{Cite journal |last=Mackenzie |first=D. S. |date=June 2008 |title=History of quenching |journal=International Heat Treatment and Surface Engineering |language=en |volume=2 |issue=2 |pages=68–73 |doi=10.1179/174951508x358437 |issn=1749-5148}}</ref> Although early ironworkers must have swiftly noticed that processes of cooling could affect the strength and brittleness of iron, and it can be claimed that heat treatment of steel was known in the Old World from the late second millennium BC,<ref>{{Cite book |title=The Oxford companion to archaeology |last=Craddock |first=Paul T. |date=2012 |publisher=Oxford University Press |isbn=9780199739219 |editor-last=Silberman |editor-first=Neil Asher |edition=2nd |volume=1 of 3 |location=New York |publication-date=2012-10-12 |pages=377–380 |chapter=Metallurgy in the Old World |oclc=819762187}}</ref> it is hard to identify deliberate uses of quenching archaeologically. Moreover, it appears that, at least in Europe, "quenching and tempering separately do not seem to have become common until the 15th century"; it is helpful to distinguish between "full quenching" of steel, where the quenching is so rapid that only martensite forms, and "slack quenching", where the quenching is slower or interrupted, which also allows pearlite to form and results in a less brittle product.<ref>{{Cite book |title=The sword and the crucible: a history of the metallurgy of European swords up to the 16th century |last=Williams |first=Alan |date=2012-05-03 |publisher=Brill |isbn=9789004229334 |series=History of Warfare |volume=77 |location=Leiden |page=22 |oclc=794328540}}</ref>

The earliest examples of quenched steel may come from ancient Mesopotamia, with a relatively secure example of a fourth-century BC quench-hardened chisel from Al Mina in Turkey.<ref>{{Cite book |title=Ancient mesopotamian materials and industries: the archaeological evidence |url=https://archive.org/details/ancientmesopotam00moor |url-access=limited |last=Moorey |first=P. R. S. (Peter Roger Stuart) |date=1999 |publisher=Eisenbrauns |isbn=978-1575060422 |location=Winona Lake, Ind. |pages=[https://archive.org/details/ancientmesopotam00moor/page/n158 283]–85 |oclc=42907384}}</ref> Book 9, lines 389-94 of Homer's ''[[Odyssey]]'' is widely cited as an early, possibly the first, written reference to quenching:<ref name=":2" /><ref>{{Cite book |title=Studies in ancient technology |last=Forbes |first=R. J. (Robert James) |date=1972-01-01 |publisher=E.J. Brill |isbn=978-9004034877 |edition=2d rev. |series=Metallurgy in Antiquity, part 2. Copper and Bronze, Tin, Arsenic, Antimony and Iron.  |volume=9 |location=Leiden |page=211 |oclc=1022929}}</ref>
<blockquote>as when a man who works as a blacksmith plunges a screaming great axe blade or adze into cold water, treating it for temper, since this is the way steel is made strong, even so Cyclops' eye sizzled about the beam of the olive.</blockquote>
However, it is not beyond doubt that the passage describes deliberate quench-hardening, rather than simply cooling.<ref>P. R. S. Moorey, ''Ancient Mesopotamian Materials and Industries: The Archaeological Evidence'' (Winona Lake, Indiana: Eisenbrauns, 1999), p. 284.</ref> Likewise, there is a prospect that the ''[[Mahabharata]]'' refers to the oil-quenching of iron arrowheads, but the evidence is problematic.<ref>R. K. Dube, 'Ferrous Arrowheads and Their Oil Quench Hardening: Some Early Indian Evidence', ''JOM: The Journal of The Minerals, Metals & Materials Society'', 60.5 (May 2008), 25–31.</ref>

[[Pliny the Elder]] addressed the topic of quenchants, distinguishing the water of different rivers.<ref>John D. Verhoeven, ''Steel Metallurgy for the Non-Metallurgist'' (Materials Park, Ohio: ASM International, 2007), p. 117.</ref> Chapters 18–21 of the twelfth-century ''De diversis artis'' by [[Theophilus Presbyter]] mentions quenching, recommending amongst other things that 'tools are also given a harder tempering in the urine of a small, red-headed boy than in ordinary water'.<ref name=":2" /> One of the fuller early discussions of quenching is the first Western printed book on metallurgy, ''[[Von Stahel und Eysen]]'', published in 1532, which is characteristic of late-medieval technical treatises.

The modern scientific study of quenching began to gain real momentum from the seventeenth century, with a major step being the observation-led discussion by [[Giambattista della Porta]] in his 1558 ''[[Magia Naturalis]]''.<ref>J. Vanpaemel. HISTORY OF THE HARDENING OF STEEL: SCIENCE AND TECHNOLOGY. Journal de Physique Colloques, 1982, 43 (C4), pp. C4-847-C4-854. DOI:10.1051/jphyscol:19824139; https://hal.archives-ouvertes.fr/jpa-00222126.</ref>