Causes of longitudinal cracks in the corners of continuous casting slabs and preventive measures1.Performance status of longitudinal cracks at the cornersOne i

Causes of longitudinal cracks in the corners of continuous casting slabs and preventive measures

1.Performance status of longitudinal cracks at the corners

One is the corner cracks associated with no detachment, and the other is the corner cracks associated with detachment. Both of these two types of corner longitudinal cracks occur at a certain corner on the inner arc side. The occurrence of corner longitudinal cracks will cause unplanned pouring of the continuous casting production, which seriously affects normal production and brings quality objections.

2. Formation of longitudinal cracks and preventive measures

Longitudinal cracks at the corners of billets and billets often encounter two situations

1) One is the problem of the corner of the copper mould tube, the shape of the corner of the tube is inappropriate or the corner is worn seriously, or the corner gap is enlarged or the fillet radius is unreasonable.

2) The heat transfer of the crystallizer is unreasonable.

If the mold fillet radius is too large, the crack will occur at the corner of the cast slab; if the fillet radius is small, the crack will occur near the exit corner. The transition part between the corner and the center (10-20mm away from the corner) is neither two-dimensional heat transfer nor close to the copper mould tube wall due to the hydrostatic pressure of the steel. Therefore, the cooling strength is the weakest, and the billet shell is the thinnest , the longitudinal cracks are most likely to be formed under the action of the hydrostatic pressure and thermal stress of the molten steel. These cracks are all cracks that are generated on the solid-liquid interface and point to the surface of the cast slab.