1. Field of the Technology
The present disclosure relates generally to the casting of metal alloys, and more specifically to the continuous casting of metallic materials such as, for example, pig iron, ferroalloys, slag, and other materials into shapes for later use as feedstock or alloying elements for use in foundry and iron and steel making operations or like metallurgical processes.
2. Description of the Background of the Technology
Heretofore, moulds used on pig iron, ferroalloy, nickel matte, slag, and ingot casting machines have been made of various compositions of cast gray iron or steel. Cast irons with carbon in flake graphite form have been found to be the most successful in terms of mould life. Typical compositions are referred to by their tensile strength, e.g. Class 40 gray iron has a tensile strength of 40,000 pounds per square inch, and Class 20 gray iron has tensile strength of 20,000 pounds per square inch.
Unfortunately, the higher strength cast irons have poorer heat-transfer properties than the lower strength compositions. Since cracking is the primary cause of failure of moulds on casting machines, it would be expected that the higher strength types would be more resistant to early failure. Unfortunately, this has not been the case, since the higher strength iron compositions do not effectively conduct the heat from the molten metal through the mould body, and can suffer local pitting and erosion in the area where the metal stream impacts the moulds. In the case of use with high temperature ferroalloys, the moulds erode severely at the metal impingement point.
The lower strength compositions do an excellent job of conducting heat, but their lower physical strength makes them prone to early failure from cracking.
It can, therefore, be appreciated that a significant advantage can be obtained by a method for manufacturing moulds of lower physical strength that are reinforced to provide resistance to cracking and subsequent breakage.