On the surface of the slab, there is transverse discontinuity, and there are obvious traces of incomplete welding, which is called heavy skin. cause:
(1) The injection flow of the mold is suddenly stopped, or the billet drawing is stopped instantaneously. If the pouring time is too long, there will be obvious reconnection on the surface of the slab;
(2) The molten steel is too viscous, the temperature is too low, the nozzle is blocked, and the injection flow is deviated, etc., which may cause heavy skin.