Dmitry Konstantinovich Chernov (or Tchernov, russian: Дмитрий Константинович Чернов; Saint-Petersburg - January 2, 1921

Yalta Yalta (: Я́лта) is a resort city on the south coast of the Crimean Peninsula surrounded by the Black Sea. It serves as the administrative center of Yalta Municipality, one of the regions within Crimea. Yalta, along with the rest of Cri ...

) was a Russian

metallurgist Metallurgy is a domain of materials science and engineering that studies the physical and chemical behavior of metallic elements, their inter-metallic compounds, and their mixtures, which are known as alloys. Metallurgy encompasses both the sci ...

.Biography and major works

He is known by his discovery of

polymorphous Polymorphism, polymorphic, polymorph, polymorphous, or polymorphy may refer to: Computing * Polymorphism (computer science), the ability in programming to present the same programming interface for differing underlying forms * Ad hoc polymorphism ...

transformations in steel and the

iron Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in ...

carbon Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent—its atom making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table. Carbon makes ...

phase diagram. This discovery is the beginning of scientific

metallography Metallography is the study of the physical structure and components of metals, by using microscopy. Ceramic and polymeric materials may also be prepared using metallographic techniques, hence the terms ceramography, plastography and, collecti ...

.A. F. Golovin ''The centennial of D. K. Chernov's discovery of polymorphous transformations in steel (1868–1968)'', ''Metal Science and Heat Treatment'', Volume 10, Number 5 / May, 196

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Biography

Chernov was born to a family of a

feldsher According to the World Health Organization, a feldsher (german: Feldscher, pl, Felczer, cs, Felčar, russian: фельдшер, sv, Fältskär, Finnish: ''Välskäri'') is a health care professional who provides various medical services li ...

(registered nurse). In 1858 he graduated from the Petersburg Practical Technological Institute and worked for the

Saint Petersburg Mint Saint Petersburg Mint (russian: Санкт-Петербу́ргский моне́тный двор) is one of the world's largest mints. It was founded by Peter the Great in 1724 on the territory of Peter and Paul Fortress, so it is one of the ...

. In 1859-1865 he was a lecturer and the museum keeper of the Petersburg Practical Technological Institute. From 1866 he was an engineer of the

Obukhovsky Steel Foundry Obukhov State Plant (also known Obukhovski Plant, russian: Государственный Обуховский Завод, Gosudarstvennyy Obukhovskiy Zavod) is a major Russian metallurgy and heavy machine-building plant in St. Petersburg, Ru ...

in Saint Petersburg. In 1880–1884 he explored the salt deposit near

Bakhmach Bakhmach ( uk, Бахмач, lit=plantations, ) is a city located in Nizhyn Raion of Chernihiv Oblast (province), in northern Ukraine. It hosts the administration of Bakhmach urban hromada, one of the hromadas of Ukraine. It has a population of ...

(currently

Ukraine Ukraine ( uk, Україна, Ukraïna, ) is a country in Eastern Europe. It is the second-largest European country after Russia, which it borders to the east and northeast. Ukraine covers approximately . Prior to the ongoing Russian invas ...

). From 1884 he was with the Government ''Naval Committee'' (морской комитет). From 1886 he was the Chief Inspector of the Rail Road Department. From 1889 he was a Professor of the

Mikhailovskaya Artillery Academy Russia has a number of military academies of different specialties. This article primarily lists institutions of the Armed Forces of the Russian Federation rather than those of the Soviet Armed Forces. Russian institutions designated as an "a ...

in Saint Petersburg.Biography

Works

Chernov obtained his major result in 1866-1868 after studying the rejects of heavy guns production as well as during analysis of practical works by Pavel Anosov, P. Obukhov,

Alexander Lavrov Alexander is a male given name. The most prominent bearer of the name is Alexander the Great, the king of the Ancient Greek kingdom of Macedonia who created one of the largest empires in ancient history. Variants listed here are Aleksandar, Al ...

, Nikolay Kalkutsky. At that time he was the curator of the small museum of the Petersburg Technological Institute. He found that steel is not the same material at all temperatures but instead has polymorphic transformations at different temperatures. He introduced different points known as Chernov's points:Chernov's points
* Point a at around 700 °C is the minimum temperature the steel should be heated to so it can be

quench In materials science, quenching is the rapid cooling of a workpiece in water, oil, polymer, air, or other fluids to obtain certain material properties. A type of heat treating, quenching prevents undesired low-temperature processes, such as phas ...

ed. By the modern theory it is the temperature of

austenite Austenite, also known as gamma-phase iron (γ-Fe), is a metallic, non-magnetic allotrope of iron or a solid solution of iron with an alloying element. In plain-carbon steel, austenite exists above the critical eutectoid temperature of 1000 ...

eutectoid A eutectic system or eutectic mixture ( ) is a homogeneous mixture that has a melting point lower than those of the constituents. The lowest possible melting point over all of the mixing ratios of the constituents is called the ''eutectic tem ...

transformation (see the picture on the right). * Point b at around 900 °C is the temperature the steel should be heated to so to correct its crystalline structure. By the modern theory it is the maximal temperature when the ferrite is stable. * Point c corresponds to the melting point of steel * Point d at around 200 °C is the temperature needed to cool the steel to quench it. In modern theory it is known as the

martensite Martensite is a very hard form of steel crystalline structure. It is named after German metallurgist Adolf Martens. By analogy the term can also refer to any crystal structure that is formed by diffusionless transformation. Properties Ma ...

transformation. Chernov was able to correctly identify the reason for these points as polymorphic transformations in the steel and even draw the first sketch of what the phase diagram for the carbon-iron system may look like. Chernov published his results in the ''Notes of the Russian Technical Society'' of 1868. His article was named "Критический обзор статей гг. Лаврова и Калакуцкого о стали и стальных орудиях и собственные Д. К. Чернова исследования по этому же предмету" (''Critical review of articles by Mr. Lavrov and Mr Kalkutzky about the steel and steel guns as well as own D.K. Chernov's research on this subject''). Many authors consider the publication of this article as the date of transformation of

metallurgy Metallurgy is a domain of materials science and engineering that studies the physical and chemical behavior of metallic elements, their inter-metallic compounds, and their mixtures, which are known as alloys. Metallurgy encompasses both the sci ...

from an art into a science. Ten years later in 1879 Chernov published a monograph named ''Research into the structure of the steel slabs'' where he described the major crystalline structures in steel and their effect on the properties of the slab. One type of steel crystal (dendrite) was named after Chernov. Chernov contributed to the theory of the

Siemens-Martin process An open-hearth furnace or open hearth furnace is any of several kinds of industrial furnace in which excess carbon and other impurities are burnt out of pig iron to produce steel. Because steel is difficult to manufacture owing to its high mel ...

. He was one of the first to suggest usage of pure

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as we ...

steel-making Steelmaking is the process of producing steel from iron ore and carbon/or scrap. In steelmaking, impurities such as nitrogen, silicon, phosphorus, sulfur and excess carbon (the most important impurity) are removed from the sourced iron, and all ...

. He also did research into the usage of

direct reduced iron Direct reduced iron (DRI), also called sponge iron, is produced from the direct reduction of iron ore (in the form of lumps, pellets, or fines) into iron by a reducing gas or elemental carbon produced from natural gas or coal. Many ores are suit ...

as well as contributed to the development of steel

gun barrel A gun barrel is a crucial part of gun-type weapons such as small arms, small firearms, artillery pieces, and air guns. It is the straight shooting tube, usually made of rigid high-strength metal, through which a contained rapid expansion of high ...

s, armor-piercing shells and emerging

aviation Aviation includes the activities surrounding mechanical flight and the aircraft industry. ''Aircraft'' includes fixed-wing and rotary-wing types, morphable wings, wing-less lifting bodies, as well as lighter-than-air craft such as hot ...

. He was one of the recognized leaders of

steel manufacturing Steelmaking is the process of producing steel from iron ore and carbon/or scrap. In steelmaking, impurities such as nitrogen, silicon, phosphorus, sulfur and excess carbon (the most important impurity) are removed from the sourced iron, and alloy ...

at the time. He was Chairman of the ''Russian Metallurgical Society'', vice-president of the ''British Institute for Iron and Steel'', an honorary member of the ''American Society of Mining Engineers'', etc.

References

{{DEFAULTSORT:Chernov, Dmitry 1839 births 1921 deaths Russian metallurgists Russian inventors Saint Petersburg State Institute of Technology alumni Engineers from Saint Petersburg Fellows of the American Institute of Mining, Metallurgical, and Petroleum Engineers