Metal-casting method and apparatus, casting system and cast-forging system

Abstract

[Purpose] To provide, in relation to casting of materials to be subjected to plastic working such as cold forging, hot forging, enclosed forging, rolling, extrusion, and roll-forming of metals, including nonferrous metals, such as aluminum and magnesium (inclusive of respective alloys), and ferrous metals (i.e., iron and steel) or to direct casting of products (i.e., castings), a metal casting method which is capable of yielding cast ingots of healthy interior metallographic structure with no cut surfaces, by making the solidification interface smooth so as to prevent generation of cracks in cast ingots which are otherwise unavoidable due to concentration of solidification shrinkage stress caused by the solidification interface becoming locally concave when the solidification interface arrives at the top surface of the mold to ultimately complete solidification, or by effecting local control of removal of heat from the mold so as to prevent generation of casting defects such as cavities and microshrinkages which are otherwise unavoidable due to the solidification interface of the molten metal in the mold forming a closed surface inside the cast ingot; a casting apparatus; and cast ingots. [Means for Solution] In a method for casting metal by charging molten metal 6 into a closed-space-definable mold 2 which includes a cooling member 1 and in which an end surface of an open/close plug 5 serves as a portion of an inner wall of the mold 2, removal of heat from a mold member 2 comprising the cooling member 1 is locally controlled in accordance with the shape of cast ingot and the location and number of the molten metal inlet(s) 4, to thereby solidify the molten metal in such a manner that the solidification interface 6 b advances to arrive at an end of an inner surface of the mold 2.

1 . A method for casting metal by charging molten metal into a closed-space-definable mold which includes a cooling member and in which an end surface of an open/close plug serves as a portion of an inner wall of the mold, characterized in that 
 removal of heat from a mold member comprising the cooling member is locally controlled in accordance with the shape of cast ingot and the location and number of the molten metal inlet(s), to thereby solidify the molten metal in such a manner that the solidification interface advances to arrive at an end of an inner surface of the mold.    
     
     
         2 . The metal casting method as described in  claim 1 , wherein an outer surface of at least one portion of the cooling member is opened during the course of solidification of the molten metal in the mold, whereby cooling an outer surface of the exposed cast ingot directly with a cooling medium.  
     
     
         3 . A metal casting apparatus for casting metal by charging molten metal into a closed-space-definable mold which includes a cooling member and in which an end surface of an open/close plug serves as a portion of an inner wall of the mold, characterized by comprising a cooling capacity control mechanism which imparts, to the mold member comprising the cooling member, a heat removal profile appropriate for the shape of the cast ingot to be produced and for the number and position of the molten metal inlet(s).  
     
     
         4 . The metal casting apparatus as described in  claim 3 , wherein the cooling member is cooled by bringing an outer surface of the cooling member into contact with the cooling medium.  
     
     
         5 . The metal casting apparatus as described in  claim 3  or  4 , wherein the cooling member has a thickness which is partially different from the thickness of the remaining portion.  
     
     
         6 . The metal casting apparatus as described in any one of  claims 3  to  5 , wherein a space is provided within a portion of the cooling member.  
     
     
         7 . The metal casting apparatus as described in any one of  claims 3  to  6 , wherein the cooling member is made of a composite material of different thermal conductivites.  
     
     
         8 . The metal casting apparatus as described in any one of  claims 3  to  7 , further comprising at least one nozzle for jetting the cooling medium toward an outer surface of the cooling member and causing the cooling medium in the form of spray or shower to hit the outer surface of the cooling member.  
     
     
         9 . The metal casting apparatus as described in any one of  claims 3  to  8 , wherein an outer surface of the cooling member is partially provided with an unevenness so that the area that can contact a cooling medium locally varies.  
     
     
         10 . The metal casting apparatus as described in  claim 9 , wherein the unevenness is holes which do not communicate with an interior surface and inclination angles of the holes are regulated to in accordance with collision angles of the cooling medium jetted in the form of spray or shower and supplied to the outer surface of the cooling member.  
     
     
         11 . The metal casting apparatus as described in any one of  claims 3  to  10 , further comprising, on the outer face side of the cooling member, means for enabling local prevention of the cooling medium from contacting the cooling member.  
     
     
         12 . The metal casting apparatus as described in  claim 11 , wherein the means for enabling prevention of the cooling medium from contacting the cooling member is a step provided at a portion of an outer surface of the cooling member.  
     
     
         13 . The metal casting apparatus as described in  claim 11 , wherein the means for enabling prevention of the cooling medium from contacting the cooling member is a heat-insulating material which partially covers an outer surface of the cooling member.  
     
     
         14 . The metal casting apparatus as described in  claim 13 , wherein the heat-insulating material is a species or a combination of species selected from the group consisting of rubber, ceramic material, and fibrous heat-insulating material.  
     
     
         15 . The metal casting apparatus as described in any one of  claims 3  to  14 , further comprising a circulation passage for cooling medium which is provided within a portion of the cooling member.  
     
     
         16 . The metal casting apparatus as described in any one of  claims 3  to  15 , wherein the cooling medium is a species or a combination of species selected from the group consisting of water, supercooled water of  0 C or lower, a volatile liquid, or an oil.  
     
     
         17 . The metal casting apparatus as described in any one of  claims 3  to  16 , wherein a temperature-controlled cooling medium is brought into contact with the cooling member.  
     
     
         18 . The metal casting apparatus as described in any one of  claims 3  to  17 , wherein contact history of the cooling medium with a cooling member is controlled.  
     
     
         19 . The metal casting apparatus as described in any one of  claims 3  to  18 , further comprising a heater provided within a portion of the cooling member.  
     
     
         20 . The metal casting apparatus as described in any one of  claims 3  to  19 , further comprising a heater provided within a portion of the mold member.  
     
     
         21 . The metal casting apparatus as described in  claim 19  or  20 , wherein the heater is a heating device making use of ohmic-resistance heating, superheated steam, or a high-temperature gas.  
     
     
         22 . The metal casting apparatus as described in any one of  claims 2  to  21 , wherein a plurality of heating sections and a plurality of cooling sections are provided within the cooling member, and functions of respective sections are controlled.  
     
     
         23 . The metal casting apparatus as described in any one of  claims 2  to  22 , further comprising a mechanism for opening at least a portion of the cooling member in the course of solidification of molten metal within a mold and a mechanism for supplying a cooling medium directly to an exposed outer surface of a cast ingot.  
     
     
         24 . A cast ingot produced by charging molten metal into a closed-space-definable mold which includes a cooling member and in which an end surface of an open/close plug serves as a portion of an inner wall of the mold, effecting a local control in terms of removal of heat from a mold member in accordance with the shape of cast ingot and the location and number of the molten metal inlet(s), causing the molten metal to solidify in such a manner that the solidification interface advances to arrive at an end of an inner surface of the mold, to thereby provide a cast ingot having no cut surface or riser portion.