ELECTRIC ARC FURNACE and die casting

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ELECTRIC ARC FURNACE:

ELECTRIC ARC FURNACE BY:-ADESANMI OLUWATOBI 1st SEMESTER(BSMARE)

INTRODUCTION:

INTRODUCTION The Bessemer and the Open-Hearth are used to manufacture the large demand of steel tonnage. However, for the supply of special and high-alloy steels other methods are used which can produce steel with less impurity and are of higher quality. These methods include the electric furnace.

THE HISTORY OF ARC FURNACE:

THE HISTORY OF ARC FURNACE 1 ST FURNACE WAS MADE IN 1907 BY A FRENCHMAN “PAUL HEROULT” THE 1 ST COMMERCIAL USE OF ELECTRIC ARC FURNACE WAS STARTED IN USA THE COST OF ESTABLISHING WAS LESS AND MINI MILL STARTED FLOURISHING THROUGHOUT EUROPE

PowerPoint Presentation:

WHAT IS AN ELECTRIC ARC FURNACE (EAF)? An electric arc furnace (EAF) is a furnace that heats charged material by means of an electric arc An electric arc furnace is heated upto 1800degree celcious by electricity that is generated through electrodes. This furnace is used for high melting point alloys such as iron and steel This method is mainly used to recycle steel

PowerPoint Presentation:

The hearth may be hemispherical in shape, or in an eccentric bottom tapping furnace A typical alternating current furnace has three electrodes. Electrodes are round in section, and typically in segments with threaded couplings, so that as the electrodes wear, new segments can be added The furnace is built on a tilting platform so that the liquid steel can be poured into another vessel for transport. The operation of tilting the furnace to pour molten steel is called "tapping To produce a ton of steel in an electric arc furnace requires approximately 400 kilowatt-hours per short ton of electricity, or about 440kWh per metric tonne; the theoretical minimum amount of energy required to melt a tonne of scrap steel is 300kWh (melting point 1520°C/2768°F).

MODE OF OPERATION:

MODE OF OPERATION Scrap metal is delivered to a scrap bay, located next to the melt shop The scrap is loaded into large buckets called baskets, with 'clamshell' doors for a base The scrap basket is then taken to the melt shop, the roof is swung off the furnace, and the furnace is charged with scrap from the basket After charging, the roof is swung back over the furnace and meltdown commences. The electrodes are lowered onto the scrap, an arc is struck and the electrodes are then set to bore into the layer of shred at the top of the furnace A time of six to ten hours is required to produce a melt, which can be poured by tilting the furnace.

Advantages of electric arc furnace for steelmaking:

Advantages of electric arc furnace for steelmaking The primary benefit of this is the large reduction in specific energy (energy per unit weight) required to produce the steel Another benefit is flexibility EAFs can be rapidly started and stopped, allowing the steel mill to vary production according to demand

WHAT AN ELECTRIC ARC FURNACE LOOKS LIKE:

WHAT AN ELECTRIC ARC FURNACE LOOKS LIKE

DIE CASTING:

DIE CASTING A TYPE OF CASTING PROCESS

WHAT IS DIE CASTING?:

WHAT IS DIE CASTING? Die casting is a metal casting process that is characterized by forcing molten metal under high pressure into a mould cavity . The mould cavity is created using two hardened tool steel dies which have been machined into shape and work similarly to an injection mold during the process. Most die castings are made from non- ferrous metals, specifically zinc , copper , aluminium , magnesium , lead , pewter and tin based alloys. Depending on the type of metal being cast, a hot- or cold-chamber machine is used. The casting equipment and the metal dies represent large capital costs and this tends to limit the process to high volume production. Manufacture of parts using die casting is relatively simple, involving only four main steps, which keeps the incremental cost per item low. It is especially suited for a large quantity of small to medium sized castings, which is why die casting produces more castings than any other casting process. [1] Die castings are characterized by a very good surface finish (by casting standards) and dimensional consistency. Two variants are pore-free die casting, which is used to eliminate gas porosity defects ; and direct injection die casting, which is used with zinc castings to reduce scrap and increase yield .

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