Archive№ 2 November 2018

Pavel Anosov, ahead of his time

In his book ‘On Damascus Steel’, Pavel Anosov, the founding father of microscopic metal analysis, wrote about the process of examining the internal structure of steel alloys under a microscope as early as 1831. “The grain is so fine that it is barely distinguishable without the aid of a microscope,” he said. His works prove beyond any doubt that he was engaged in microscopic research 20 years before the British natural scientist Henry Clifton Sorby, thus laying the foundations of microscopic analysis of metals.

Launched the domestic production of crucibles. In the second half of the 19th century, crucibles were the main tool for steelmaking; however, they could only be purchased abroad and were expensive. Anosov developed high-quality and relatively cheap crucibles (40-50 kopecks each) for use at the Zlatoust armaments factory, using local refractory clay mixed with finely crushed charcoal.

Learning to make high-quality cast steel. In Anosov’s time, steel was made by carburizing iron, which was then melted in crucibles. Anosov proposed combining these two processes, proving that it was possible to carry out surface saturation of iron with carbon by means of furnace gases, which contain carbon. This method was called "gas cementation of metal".

Anosov established the effect of macrostructure on the mechanical properties of metal. He developed etching as a method to reveal metal macrostructure. His outstanding work, ‘A Description of Experiments Made to Obtain Damascus Steel: The Understanding Gained from Said Experiments; The Difference between Damascus Steel and Regular Steel, and The Discovery of the Very Means of Manufacturing Damascus Steel’, was translated into other languages and is a treasured work in global literature on metallurgy.


As manager of the Zlatoust factory, Pavel Anosov did much to develop the potential of local raw materials for iron making. He led exploration work to discover new ore deposits and worked on the mapping of mineral resource distribution in the Ural Mountains



Dmitry Chernov, improving the quality of steel

Russian scientist Dmitry Chernov was an outstanding and gifted individual. His interests were not confined to engineering and metallurgy. He was an accomplished violinist, who was interested in the different means of drying, gluing and forming violin bodies, creating lacquer products and building stringed instruments himself. His violins, violas and cellos were held in high esteem by musicians. He also made contributions in the field of aviation. He demonstrated that the lift fr om a propeller depends on its speed of rotation and the angle of attack of the blades. For this purpose, he hand-made a unique model comprising a spring mechanism and a rotating propeller. The aerodynamicist and “father of Russian aviation” Nikolay Zhukovsky covered Chernov’s experiments in detail in his lectures on aerodynamics and aviation theory.

Discovery of factors affecting the quality of steel. During his time at the Obukhov Factory, Chernov investigated the causes of frequent steel defects in guns. He found that the steel at the places wh ere gun barrels most often ruptured had a coarse-grained structure, while the metal in defect-free weapons had the same chemical composition, but a fine-grained structure. Chernov used experiments to establish the relationship between thermal transformations and the properties and structure of steel. He proved that the decisive factor for obtaining high-quality steel is thermal, rather than mechanical, processing.

Inventor of metallography. Chernov pioneered the theory of the structure of metals and alloys. His method for the construction of diagrams showing the internal transformations, which occur when steel reaches critical points, were prototypes for the subsequent development of fusibility diagrams and diagrams showing the state of equilibrium systems. Chernov’s work led ultimately to the emergence many years later of thermal analysis, which is the principal laboratory method for studying saline solutions, metal alloys and many other substances.

Improvement of the Bessemer process (transformation of molten iron into steel by blowing air through a converter - Ed. note). Chernov made improvements to the construction of Bessemer converters and divided the process into four parts, defining the precise start and end of the process for the first time.

 

He was helped in this by his observations of changes in the composition of molten metal through spectral analysis of the flame emerging from the mouth of the converter. Having studied over 500 spectrograms he was able to determine when to end the air blow and so control the pig iron conversion process.

Chernov investigated the structure of cast steel. He spent a long time studying the causes of various defects—porosity, brittleness, shrink holes—and ways of preventing them. From observations of crystal formation in freezing water and saline solutions and from studying steel ingots he devised a theory of crystallisation of steel. He invented the concepts of:

  • crystallisation centres;

  • solid crystalline solutions;

  • the wave nature of crystal growth.


 

Chernov’s work paved the way for an improved Bessemer process with wider applicability – for example, it was possible to convert pig iron with low silicon content by first melting and overheating it in a cupola or other suitable furnace.

Vladimir Grum-Grzhimailo, furnace master

According to his students, Vladimir Grum-Grzhimailo was the perfect teacher. His lectures to aspiring metallurgists seemed to be delivered in a single breath. One of his first courses in St Petersburg was given in the form of an extended application of the laws of physical chemistry to analysis, a manner revolutionary for the early years of the 20th century.

In the foreword to his book ‘Steel Manufacture’, he wrote: “It was the most absorbing work. The fog that had surrounded me for 22 years working in steelworks began to disperse and it became clear that making liquid steel was a splendid illustration of Le Chatelier’s principle” (Le Chatelier's Principle of Shifting Equilibria – Braun – Ed.).

Design of blast furnaces. In his first year working at Nizhny Tagil steel plant, the young Grum-Grzhimailo was instructed to redesign the blast furnace for smelting of ferro-manganese. His design, which used blast-furnace gas to heat air, doubled furnace productivity and reduced losses of manganese during the alloy smelting process by seven times. While working at the Nizhnyaya Salda iron and steelworks he designed a fully functioning rail mill using Russian-made equipment. As a result, the output of high-quality products increased 2.5-fold at a third of the cost.

Grum-Grzhimailo was the first to use the laws of physical chemistry (in particular, on system equilibrium in response to changes in temperature and on mass action – Ed.) to explain the processes occurring in molten steel inside an open hearth furnace and Bessemer converter. He stated precisely:

  • the requirements governing the charge mixture (the materials charged into a steel furnace and other units to obtain an end product with a specified chemical composition and a given degree of quality – Ed.);
  • the composition and degree of heating of the charge to guarantee a high-quality product at the end of the process.

A new hydraulic theory. The hydraulic theory of Grum-Grzhimailo was the first attempt in the world to create a scientific method with general application for calculating furnace parameters. It was described in detail in his book Open-Flame Furnaces and widely recognised both in Russia and abroad.

Building on an idea described by Mikhail Lomonosov in his work ‘On Free Movement of Air, Observed in Mines’ and the statement that ‘A flame in a furnace obeys the same laws of motion as a lighter fluid in a heavier fluid (or a flame in external air)’, he applied the laws of hydraulics to the motions of furnace gases and, together with the hydraulic engineer Iosif Esman, calculated the ‘height of the gas plume’ and ‘gas overflow’ in furnaces.

From studying the properties of refractory materials and especially Dinas brick (a refractory material made of quartzitic and quartz rocks, at least 93% silica, widely used in furnace crowns – Ed.) Grum-Grzhimailo devised his ‘Dinas degeneration theory’. In his book ‘Rolling and Groove Designing’ he revealed the design secrets of the rollers in rolling mills (the working parts, which affect the deformation of the workpiece into the required shape and dimensions – Ed.)

The design of a number of industrial furnaces was based on the principles described by Grum-Grzhimailo:

  • continuous furnace (heating of ingots prior to rolling);

  • forging furnace (heat treatment of metal);

  • drying furnace;

  • annealing furnace;

  • open hearth furnace.

Grum-Grzhimailo’s hydraulic theory was the basis for the design of 800 furnaces, which were built and successfully launched into operation.

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