During cutting of samples for the mechanical and metallographic tests, numerous gas holes and pores were detected that
resulted from the casting process, Fig. 9. Gas pores and holes were not perceived around the crack initiation location, i.e.
around the outer shaft surface, but exclusively in the casting volume.
2.2. Chemical composition
Table 1 shows the chemical composition of flange material in accordance with the requirements of the reference standard
[6]. The testing determined that the chemical composition meets this standard’s requirements.
2.3. Mechanical properties
For the purpose of comparability of the testing results with the reference standard values [6], the tensile test was
performed in conformity with the GOST 1497-84 standard requirements [8]. The test results are shown in Table 2. The samples
were cut out from a casting, in direction parallel to the main shaft axis. Tensile specimens (15 specimens) were made