Correctional steels are alloyed and non-alloyed machine manufacturing steels, whose chemical composition is particularly suitable for hardening, in terms of carbon content, and which have a high tensile strength at a certain tensile strength at the end of the treatment process. The treatment process is described first as a whole hardening and subsequent tempering processes, to give the steel part high toughness. Due to the superior mechanical properties they provide at the end of the treatment process, correctional steels are mainly in the production of various machinery and engine parts, forged parts, nuts, bolts and studs, crankshafts, axles, control and drive parts, piston rods, various shafts, gears and shafts. They form an important part of machine-manufacturing parts.
The selection of the appropriate breeding steel and the application of the correct breeding process is a phenomenon that requires a lot of attention and experience. The good results of the improvement process (achieving the desired hardness and toughness values) are closely related to the internal structure cleaning of the steel used. Internal structure cleaning is concerned with the removal of impurities (such as hydrogen, oxygen, nitrogen) dissolved in the liquid steel and cleaning from oxide, sulfur inclusions.