Kropyvnytsky sheet, circle tool steel U8A, HVG, 9XC, 5HNM, R6M5, spring-loaded 65G

A special kind of steel alloy is spring steel. Spring steel has a number of features - a very high yield strength, hardness, an acceptable level of corrosion resistance. Such material can bend, change its shape under the influence of external factors. During compression, it retains all its physical properties (strength, mechanical stability, chemical inertness). If such a spring is released, the material will return to its normal shape with all physical properties preserved. Spring steel is an alloy that has a very high yield strength. Yield strength is a physical property of a material that characterizes the stress at which the strain continues to increase without increasing the load. In fact, this indicator reflects the ability of the material to maintain its shape when bending and twisting. The better the material retains its shape during deformation, the higher its yield strength. A high yield strength occurs in the material due to special processing methods (quenching, tempering). This distinguishes spring steel from many other steel alloys, which usually "acquire unusual properties" due to the inclusion of various alloying additives in their composition. For the production of spring steel, low-alloy alloys are used with a minimum amount of additional components. In American, European, Asian countries, medium and high carbon compounds containing chromium are also often used. Compounds containing a large amount of manganese, nickel, silicon, tungsten, and nitrogen are also used. These components make the material even more plastic, and also increase its chemical inertness (that is, such a material will not react with alkalis, acids, salts). As the name implies, spring steel is commonly used in the production of springs, torsion bars, leaf springs, piano strings, clamps and many other products. We got acquainted very briefly only with the most common steel grades used in mechanical engineering, far from having exhausted their complete list. When designing, they also use automatic, foundry, tool, ball-bearing, spring-spring, heat-resistant, transformer and many other grades of alloy steels. However, the creators of new, even more powerful machines, working with heavy loads and high temperatures, require materials with even better qualities. Therefore, metallurgists create more and more new alloys, using the methods developed by science, achieve such properties of materials that could not be obtained before. The calibrated steel is manufactured according to the technical requirements of GOST 1051-73, which applies to round, square, hexagonal and rectangular cold-drawn calibrated carbon structural steel (GOST 1050-74), steel of increased and high machinability (GOST 1414-75), alloyed structural steel (GOST 4543 -71), as well as alloyed and carbon tool, high-speed, spring-spring, corrosion-resistant, heat-resistant and heat-resistant. According to their purpose, steels are classified into structural and tool steels. Structural steels represent the most extensive group intended for the manufacture of building structures, machine parts and devices. These steels include cemented, improved, high-strength and spring-loaded steels. Tool steels are subdivided into steels for cutting, measuring tools, dies of cold and hot (up to 200 ° C) deformation. The book discusses various groups of materials most commonly used in mechanical engineering - structural steels, cast irons, spring steels and alloys, tool steels, maraging steels, corrosion-resistant and heat-resistant steels and alloys, new steels for chemical-thermal treatment. The M method is used for acceptance and intermediate control of carbon and alloy tool steels, ball and roller bearing steels, structural carbon and alloy steels (with a content of 0.3% C), spring-spring, etc. In practice, low-temperature, medium and high tempering is used. Low-temperature tempering is carried out at 150–250°C for 1–2 hours. Such tempering sometimes causes an increase in hardness on HPC 1–2 as a result of the decay of residual austenite. Low-temperature tempering is used for tool steels, products after carburizing and surface hardening. Spring and spring steel are subjected to medium tempering at 350-400°C and a troostite structure is obtained with a hardness of HPC 40-45 and sufficient toughness. High tempering is carried out at 450-650°C. In this case, with appropriate exposure, granular sorbitol is formed in the structure, in contrast to the lamellar sorbitol obtained during normalization. Steels with a granular sorbitol structure have a significantly higher impact strength than steels with lamellar sorbitol. Therefore, high tempering after hardening is carried out for parts that experience shock loads during operation.