Structural steel is a manufacturing material with a specific form, profile, cross section. Both chemical composition and physical properties are determined by standards. EN 10025 is the most comprehensive standard for structural steels. EN10025 has determined carbon steels, high strength low alloy steels, high corrosion resistant high strength low alloy steels, tempered steels as classes of structural steels. Boilers, pressure tanks, pipes, buildings and constructions are products made by using structural steel.
In another aspect, applications such as shape completeness, dimension completeness, resistance, hardness, fatigue strength, surface quality, higher flow and tensile strength, ease of use, safety, etc. can be performed using structural steel.
Because structural steel can be processed in many different ways in the factory, it provides unlimited creative possibilities for designers.
All these superiorities have made structural steel that we selected as the cover subject of this issue as one of the most important materials of our age.

LOW AND HIGH ALLOY CARBON STEELS
Alloyed carbon steels contain high amounts of alloying elements such as nickel, chromium, manganese, cobalt, niobium and vanadium. Alloyed steels are divided into two classes as low alloyed and high alloyed steels according to the ratio of alloying elements. Steels with less than 5% alloy alloy are low alloyed steels and are mostly used in the production of high-strength structural elements and machine parts. In all steels, the basic element that provides the martensite phase in the quenching process is carbon. Therefore, alloy steels with sufficient carbon content can be hardened by quenching. In high alloyed steels, the alloy element is over 5%. These steels are often used for special purposes. High-impact-resistant mold steels containing 18% Cr and 8% Ni-containing stainless steel, 14% Mn containing high impact strength steel, 20% Cr can be shown as examples.