Gradient material molded body

Abstract

A gradient material molded body, obtained in continuous casting from at least one metal alloy solidified in an outer shell of the molded body, outside the thermodynamic equilibrium. A method for manufacturing a gradient material molded body, wherein the molded body is cast into its finished form in continuous casting from at least one metal molten mass which is alloyed supersaturated, and wherein an outer shell of the molded body is chilled into its crystal lattice in the course of said casting.

What is claimed is:  
     
         1 . A gradient material molded body, obtained—as a finished component close to a final contour and not as a semi-finished product—in continuous casting from at least one metal alloy solidified in an outer shell of the molded body outside the thermodynamic equilibrium.  
     
     
         2 . The gradient material molded body as set forth in  claim 1 , characterized in that the molded body is solidified in a core stably and/or in the thermodynamic equilibrium.  
     
     
         3 . The gradient material molded body as set forth in  claim 1 , characterized in that the metal alloy is a casting alloy.  
     
     
         4 . The gradient material molded body as set forth in the preceding claim, characterized in that the metal alloy is not a wrought alloy.  
     
     
         5 . The gradient material molded body as set forth in  claim 1 , characterized in that the metal alloy is a casting iron alloy.  
     
     
         6 . The gradient material molded body as set forth in  claim 1 , characterized in that the metal alloy is a tool steel alloy having a carbon content of at least 0.8 to at most 1.5% in the mean, and a chromium content of at least 5 and at most 12%, and contains at least one of the elements vanadium, molybdenum and tungsten as a further alloying element, wherein the vanadium content is at most 10%, the molybdenum content is at most 1.5% and the tungsten content is at most 1%.  
     
     
         7 . The gradient material molded body as set forth in  claim 1 , characterized in that the molded body is a functional component, preferably a cylindrical rotating body, for a processing machine.  
     
     
         8 . The gradient material molded body as set forth in  claim 1 , characterized in that the molded body is a roll barrel for processing a web-shaped material or an abrasion-proof casting body for milling, crushing, grinding or chafing.  
     
     
         9 . The gradient material molded body as set forth in  claim 1 , characterized in that the outer shell exhibits a thickness between 1% and 20% of the mean distance between the surface of the shell and a central longitudinal axis of the molded body.  
     
     
         10 . The gradient material molded body as set forth in  claim 1 , characterized in that a white-solidified iron base alloy forms the shell.  
     
     
         11 . The gradient material molded body as set forth in  claim 1 , characterized in that the molded body is cast from a single metal alloy, preferably an iron base alloy.  
     
     
         12 . The gradient material molded body as set forth in  claim 1 , characterized in that the shell and a core of the molded body are formed by different metal alloys, wherein each of the metal alloys are preferably iron base alloys.  
     
     
         13 . The gradient material molded body as set forth in  claim 1 , characterized in that the molded body is a compound molded body having fibers extending in the longitudinal direction of the molded body and cast-in by the metal alloy.  
     
     
         14 . A method for manufacturing a gradient material molded body, wherein the molded body is cast into its finished form in continuous casting from at least one metal molten mass which is alloyed supersaturated, and wherein an outer shell of the molded body is chilled into its crystal lattice in the course of said casting.  
     
     
         15 . The method as set forth in the preceding claim, characterized in that the molded body is cast in a vertical billet.  
     
     
         16 . The method as set forth in  claim 14 , characterized in that the metal molten mass is formed using a base metal and at least two alloying elements, wherein each of the alloying elements are alloyed in a proportion which at most reaches as far as the nearest ternary eutectic.  
     
     
         17 . The method as set forth in  claim 14 , characterized in that the base metal is aluminum, titanium, iron, nickel or copper, and the alloying elements belong to the group comprising boron, carbon, silicon, phosphorus, sulfur, titanium, vanadium, chromium, manganese, nickel, copper, cobalt, zirconium, molybdenum and tungsten.  
     
     
         18 . The method as set forth in  claim 14 , characterized in that the metal molten mass is a sub-siliconized iron base molten mass with a silicon content of at least 0.1% and at most 1.2%.  
     
     
         19 . The method as set forth  claim 14 , characterized in that the metal molten mass is supersaturated with carbon, with a carbon content of at least 0.2% and at most 5%.  
     
     
         20 . The method as set forth in  claim 14 , characterized in that the metal molten mass is a tool steel alloy having a carbon content of at least 0.8 and at most 1.5% and a chromium content of at least 5 and at most 12%, and contains at least one of the elements vanadium, molybdenum and tungsten as a further alloying element, wherein the vanadium content is at most 10%, the molybdenum content is at most 1.5% and the tungsten content is at most 1%.  
     
     
         21 . The method as set forth in  claim 14 , characterized in that the method is carried out in such a way that a predetermined elasticity modulus is set in cross-sections of the molded body, taken as a mean over the respective cross-section, and preferably in all cross-sections of the molded body.  
     
     
         22 . The method as set forth in the preceding claim, characterized in that a physical parameter of the casting body is measured during casting and fed back as a regulating variable to a regulation of the method, wherein the physical parameter is chosen such that the resultant elasticity modulus may be concluded from it.  
     
     
         23 . The method as set forth in  claim 14 , characterized in that the metal molten mass is cast into a continuous billet in a device for continuous casting, and in that a mean withdrawal speed of the billet fulfils the relation v m ≦7×10 7 ×D −z , wherein v m  is the mean withdrawal speed in mm/min, D is the outer diameter of the molded body in mm and z is a non-dimensional factor having a value between 1.9 and 2.0.  
     
     
         24 . The method as set forth in the preceding claim, characterized in that an instantaneous withdrawal speed is periodically changed.  
     
     
         25 . The method as set forth in the preceding claim, characterized in that resultant stationary phases of the billet have a duration of five seconds at most.  
     
     
         26 . The method as set forth in  claim 14 , characterized in that the metal molten mass is cast as a shell around a core likewise formed in continuous casting beforehand, or around an imported core.  
     
     
         27 . The method as set forth in the preceding claim, characterized in that the core is continuously cast from a molten mass, and the molten mass for the core comprises a different composition of alloy than the molten mass for the shell.  
     
     
         28 . The method as set forth in  claim 14 , characterized in that a core billet continuously cast in a first casting die is guided through a second casting die and is cast-in in the second casting die with the shell.