Mounting form ladle turret anchor bolts with cyclically alternating impact loads

The anchor bolts are directly buried and no corresponding measures are taken. For steel, increasing its plasticity will result in a decrease in toughness. Straight-buried anchor bolts are used and no bushings are installed. On the one hand, the toughness of high-strength bolts is reduced under the constraints of concrete; on the other hand, scratches may be left on the surface of high-strength bolts during installation, causing stress concentrated. In summary, improper material selection is the main reason for the low stress brittle fracture of these anchor bolts. The wrong heat treatment process and installation form make the occurrence of low stress brittle fracture possible.

Materials For engineering materials, it is especially important to have comprehensive mechanical properties, ie the material is required to have a toughness that matches its strength. In engineering design, one-sided pursuit of high strength and neglect of matching toughness often produces unintended consequences. A large number of engineering practices have proved that the failures of use occurring below the creep temperature are mostly not caused by the general plastic deformation, but due to the fracture occurring under the condition that the nominal stress is lower than the yield stress, so-called low stress brittleness. fracture.

In engineering design, in order to achieve a better combination of strength and toughness, in the selection of materials, one should pay attention to the organization of the material, because the organization determines the performance, for high-strength steel, the quenched structure should be low-carbon martensite or chin Second, we must pay attention to the size effect of the material, because the large structure and thick section have lower toughness than small parts and thin sections. When selecting high-strength steel parts, the carbon content should be reduced to a low level to ensure the toughness, and the high strength is guaranteed by alloying. The installation form ladle turret anchor bolts are subjected to periodic alternating impact loads, and high-strength anchor bolts are used. The design should use replaceable anchor bolts (ie live bolts) for easy installation and replacement during use. Also pay attention to the structure of the bolt, reduce the groove, hole and sharp angle to eliminate the influence of stress concentration as much as possible.