Influence of dimensional size of rolled product made of S690QL steel on impact toughness and grain size
Fine-grained structural steel of the S690QL designation is widely used due to its very good mechanical properties and good weldability and bending, resistance to abrasion and corrosion. It is most often made in the form of plates of different thicknesses. S690QL steel plate has excellent performance characteristics and is used when low temperature resistance and important strength components are required. It is used in addition to applications for construction machines and structures, mining machines and in the energy sector, highways, railway bridges, etc. Since this steel is used in very demanding conditions such as low temperature, it is very important to test the mechanical properties of the impact toughness at these temperatures. Toughness is an important property that can indicate a material's tendency towards brittle fracture. In this work, a large number of samples were tested for this property, i.e. impact toughness at a temperature of -40°C taken from plates of different thicknesses made of S690QL steel. In addition to this property, the grain size of this steel after heat treatment is also taken into account. These characteristics and their mutual dependence provide directions for correcting the production of semi-finished products or finished products.