Cross-section fractures

Cross-section fractures - Slab defects

Figure 1: Cross-section fractures.

Defect name: Cross-section fractures
Record No.: 1439
Type of defect (Internal/Surface): Surface
Defect classification: Slab defects
Steel name: Steel
Steel composition in weight %: No data.
Note: For this study we only selected the steel charges which were cast into pipe billets Ø250mm respectively Ø270mm, using all steel grades (carbon, low-alloyed, respectively alloyed) used in making these two types of pipe billets.
The cross-section fractures presented if figure 1 are seldom met at the round profiles, arising due to the strain in the longitudinal direction of the thread. They are ground if they are not deep (within the admissible limits foreseen for diametre and ovality). The causes leading to cross-section fractures are: thermal stress due to the irregular solidification of the shell and the additional stresses due to the tumultuous flow under the meniscus, the meniscus level variation and the thread friction in the mould.
Reference: Not shown in this demonstration version.