One of the most important achievements in the field of arc welding is the development of welding improved structural alloy steels. A distinctive feature of these structural steels is their tendency to harden and deep prolistibility at moderate cooling speeds.
Such steels after hardening are released at temperatures determined by the requirements for their mechanical properties in a thermally processed state. By changing the vacation temperature, you can get steel that differs very much in strength and deformation ability. Improved steels are widely used in mechanical engineering and are the most important structural material in military equipment. In particular, the majority of armor steels belong to the class of improved subcutaneous prosperity of these steels and the high mechanical properties due to it are very important quality indicators that determine the working conditions of structural steel in operation. At the same time, the tendency of improved steels to hardening for a long time was a difficulty for the use of these steels in the manufacture of machine -building structures and weapons from them. During the Second World War alone, large research work was carried out in this area, which, in combination with accumulated production experience, made it possible to successfully resolve this complex technological task. Most of the improved steels used in the modern technique are multicomponent systems in which, mainly manganese, nickel, chrome, molybdenum and vanadium are used as alloying elements. The carbon content in these steels is usually much higher than in low -alloy structural steels used in annealed or normalized state.