The main reasons for desquamation:

In the crystallizer, the cooling of the billet shell is uneven and the thickness difference is large, which causes unevenness of the billet shell in the crystallizer and secondary cooling zone. due to uniform shrinkage. When the billet shell condenses and shrinks, the thick corners (or faces) of the billet shrink a lot, while the corners (or faces) of the billet thin shrink a little, and the cooling intensity is high (shrinkage is also large). An acute angle is formed at the corner or between two surfaces; an obtuse angle is formed at the corner or two surfaces where the cooling intensity is small (the amount of shrinkage is also small).

Preventive measures: 1. Appropriate taper of the crystallizer

2. Increase the amount of water in the four corners of the billet after the crystallizer

3. Accurate alignment of the 600mm distance below the crystallizer Arc

4 Strengthen cooling and eliminate intermittent boiling of the crystallizer

According to the situation you described, there is some dry skin on the surface of the copper tube of the crystallizer after it is removed. It may be affected by it. The cooling of the slab leads to uneven shrinkage. However, to accurately determine what caused the slab to peel off, you have to go to the site to see it. I hope it can help you!