Casting Of Ingots
Subsequently the molten steel has been poured as of the steel making furnace this has to be transformed in solid shapes known as ingot. The ingot is additional processed via rolling it into shapes, casting this into semi-finished forms, or forging. For removing the need for ingot the shaping procedure is being rapidly replaced through continuous casting, therefore improving effectiveness. The molten metal is poured or teemed from the ladle into ingot moulds whether the metal solidifies. Moulds are generally made of cupola iron or blast-furnace iron, along with 3.5 percent carbon, and are tapered to facilitate the removal of the solid metal. The moulds bottoms may be open or closed; if open, the mould is placed upon a flat surface. The taper might be such as the big end is down.
The cooled ingots are eliminated or stripped from the moulds and lowered into soaking pits; here they are reheated to an identical temperature of about 1200oC for subsequent processing via rolling. Ingots might be square, round, or rectangular in cross-section, and their weights ranges from a few hundred kgf of 40 tons.
Specific reactions take place throughout the solidification of an ingot that in turn have significant influences on the steel quality. For demonstration, significant amounts of oxygen gas and other gases can melt in the molten metal throughout steel making. Even so, much of these gases are refused throughout solidification of the metal as the solubility limit of gases in the metal reduces sharply similar to its temperature decreases. Refused oxygen combines along with carbon, forming carbon monoxide in the solidified ingot that causes porosity.
Three types of steel are generated depending upon the amount of gas developed during solidification. These types are as: killed, semi-killed, and rimmed.