Where are steel metal plates used?
The use of metal in modern technologies, as well as constructions is diverse, even the ballistic protection of cars from small-caliber bullets consisted in the imposition of a steel sheet (with hardness of 600 HB), steel HHS plates (with hardness of 480-540 HB), or screens made of them.
Even in the printing office, a printing technology is
impossible without the use of steel plates with an average thickness of 0.5 mm made of hardened steel (hardness of 60-70 units. ST60G, ST65.) The construction of wooden structures is based on the use of steel plates of various shapes and purposes: plasma-beam cutting helps make armature keys from a steel plate 1 mm in thickness (25 mm in height), foot-irons, made from a steel plate 10 mm in thickness and 50-70 mm in width, various steel connector plates with needle nails, 25-125 mm in width. In the house facilitation, the heating system cannot do without steel plates: two plates of 1.2–2 mm with stamped pricks form a section of the radiator.
Steel plates are also used in transformer manufacturing, as well as in architecture, as decoration and in many other fields of the economy, science and production.
Plasma-beam cutting of metal helps cut plates from hot rolled steel, which is divided into universal, 60 in mm thickness, 4 mm thin-sheets.
High tensile steel, with a high content of more than 45% silicon, has a high brittleness. If the ordinary metal cutting (non-plasma-beam) is used, then you can obtain uneven edges, sometimes even with wire edges. Accordingly, such steel costs less as compared to cold-rolled steel. Hot rolled steel plate is heat treated only once after rolling. Due to the low chemical and physical properties, it is not used for the production of enameled products, because the crystals in the crystalline grid are arranged chaotically, the diffusion of hydrogen is increased, and it has a small fill
ing factor. The surface of the steel up to 2 m is always etched, and that’s why it belongs to the 1st category steel.
Hot-rolled steel is determined by dimensions: with a thickness of 0.5-3.9 mm – length 1200-5000 mm, width 600 – 1500 mm; length 1200-1600, width 600-1800 mm .; length is 1200-6000 mm., width 600-1800 mm.
It is worth noting that the cooling rate depends on the diameter and is directly proportional: the greater the thickness of the steel, the slower the cooling. In general, hot-rolled steel is inferior in its properties to cold-rolled increased development of cracks and is used less and less in production.
The cooling rate depends on shape and size of the steel plate when hardened, the thermal conductivity of cooling medium, the degree of dependence on the alloying composition and content of carbon. If carbon is less than 20%, then steel should not be hardened just yet.
When producing high strength steel plates, initial stress occurs for two reasons – the temperature difference over time and the ambiguous course of the process of phase production in different parts of the hardened product.