Start-up billet head for a continuous casting machine for metal, in particular, steel

Abstract

A start-up billet head for a continuous casting machine for metal closes off an outlet of the casting die before start-up of the casting process. The start-up billet head has a coupling part facing an interior of the casting die and forms together with a billet cast in the casting die a positive-locking, hook-shaped connection. The connection can be decoupled after leaving the casting die by performing a tilting movement of the start-up billet head about a joint of the start-up billet. The coupling part has a recess with a first side active in a billet removal direction and a second side facing the first side. The first and second sides have oppositely oriented arc shapes. The coupling part has the shape of a preliminary billet profile with at least one undercut located in the area of at least one flange or angled joint of the preliminary billet profile.

What is claimed is:  
     
         1 . A start-up billet head for a continuous casting machine for metal, wherein the start-up billet head is configured to close off an outlet of a continuous casting die before start-up of the casting process; the start-up billet head comprising: 
 a coupling part facing an interior of the casting die configured to form together with a billet, that is cast in the casting die, a positive-locking, hook-shaped connection, wherein the connection is configured to be decoupled after leaving the casting die by performing a tilting movement of the start-up billet head about a joint of the start-up billet;    the hook-shaped coupling part having a recess with a first side active in a billet removal direction and a second side facing the first side;    the first side of the hook-shaped coupling part having an arc shape and the second side having an arc shape oriented opposite to the arc-shape of the first side;    the coupling part having a shape of a preliminary billet profile and comprising at least one undercut configured to be located in the area of at least one flange or at least one angled joint of the preliminary billet profile.    
     
     
         2 . A start-up billet head according to  claim 1 , wherein the preliminary billet profile is a double-T profile having two flanges and a stay connecting the flanges, wherein the two flanges of the billet profile are provided with one of the undercuts, respectively, and wherein the undercuts are symmetrically arranged.  
     
     
         3 . A start-up billet head according to  claim 1 , wherein the at least one undercut begins parallel to a stay of the preliminary billet profile and then follows a transition between the stay and the flange of the preliminary billet profile end extends within the flange with a certain proportion of the thickness of the flange.  
     
     
         4 . A start-up billet head according to  claim 1 , wherein on the active side of the hook-shaped coupling part a flange wall is formed whose wall surface extends into the area of the undercut.  
     
     
         5 . A start-up billet head according to  claim 4 , wherein the flange wall has a thickness which corresponds approximately to half the thickness of the flange.  
     
     
         6 . A start-up billet head according to  claim 1 , wherein the preliminary billet profile has a stay connected to the flange and wherein, with decreasing thickness of the stay of the billet profile, the at least one undercut is limited to the at least one flange or angled joint of the preliminary billet profile.