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, 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:
Point a at around 700 °C is the minimum temperature the steel should be heated to so it can be quenched. By the modern theory it is the temperature of austeniteeutectoid transformation.
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 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 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". Many authors consider the publication of this article as the date of transformation of metallurgy 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 was named after Chernov. Chernov contributed to the theory of the Siemens-Martin process. He was one of the first to suggest usage of pure oxygen in steel-making. He also did research into the usage of direct reduced iron as well as contributed to the development of steel gun barrels, armor-piercing shells and emerging aviation. He was one of the recognized leaders of steel manufacturing 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.
