Features of deformation behavior of structural steel during forging

The paper presents the studies of the structural steel subjected to forging including severe plastic deformations. The purpose of this work is to evaluate the role of severe plastic deformations during the forging of steel blanks. The computer simulation of the operations of forging steels of grades 20, 45 and 40H in the software complex DEFORM 3D was performed. A detailed analysis of the stress-strain state of the blanks during deformation is carried out, as well as the load schedule. As a result of the analysis it was revealed that the nature of the stress-strain state under equal conditions is determined by the material of the billet. An increase in stress and strain effectiveness is shown depending on carbon increasing in steel under identical conditions. The choice of the most optimal process parameters for different technological conditions using simulation in the DEFORM 3D software complex is completely justified, and can yield concrete results, even for complex deformation processes. The deformation behavior of 20, 45, and 40H steels was studied during forging with a degree of deformation at a draft of 30 % and with severe plastic deformation by the forging method in trapezoidal dies of steel 45 in industrial conditions. As a result of the forging, a uniform microstructure with a grain score 7 is formed. The use of severe plastic deformation promotes the intensification of the rotational deformation mechanism. The implementation of shear deformations provides grain refinement to 8 points. In this case, the hardness of steel 45 after the realization of severe plastic deformation increased by more than 13 % compared to the metal obtained by the conventional sediment and amounted to 164.8 HB. The influence of technological features of forging on the microstructure and properties of structural steel, especially on the prevailing deformation mechanism is revealed.