| Abstrakt: |
Steel grade SS34 has found wide application in the oil and gas industry. This steel is low-carbon. The choice of this steel is explained by its good properties for industrial facilities, such as weldability, non-hardening. A number of studies were carried out in the work, which included testing samples in a heat-treated state and free. To obtain an equilibrium structure, annealing was carried out. As a result of the experiment, it was shown that after annealing, the structure of SS34 steel acquired high plasticity, but low hardness and strength indicators were noted. Tensile tests of steel samples under static uniaxial loading were also carried out. As a result of such experiments, the main indicators of plasticity and strength of the metal under study were determined. Using the Rockwell method, the changes in the hardness of metal samples were studied. An optical microscope was used to determine the changes in the microstructure, and it was shown that the structure of the steel is ferrite-pearlite. The difference between the structure of the metal in the free and heat-treated state is also noted. In the initial state, it is fine – grained; in the processed state, it is homogeneous, the texture of deformation disappears. In the initial state of the steel grade SS34, scribbling was detected, and the liquation band was also clearly traced. It is shown that there is a chemical heterogeneity on the metal at this point, which is explained by the presence of impurities (oxides, nitrides, sulfides, silicides). |
