Detailed discussion of Continuous Casting Process | Continuous Casting Process with its Advantages, Dis-Advantages and Limitations

Introduction:

Continuous casting also terms as strand casting, in this process where a metal is heated until it liquefies. The molten metal is then allowed to solidify until it becomes a semi-finished slab that's later rolled within the finishing mill. it is wont to cast metals of uninterrupted lengths. In this cycle, the liquid metal is ceaselessly provided to the form. The mold has an indeterminate length. At the point when the liquid metal is projected through a form, it continues voyaging lower expanding in its length as time cruises by. The molten metal has continuously skilled the mold, at an equivalent rate to match the solidifying casting. This leads to the casting of long strands of metal. The whole process of continuous casting may be a precisely deliberated process that will produce outstanding results.

Working Process:

The metal is first liquefied and poured into a tundish, which may be a container that results in the mold which will cast the steel.

The tundish is placed about 80-90 feet above the bottom level and therefore the whole process of casting uses gravity to work. 

The tundish is consistently furnished with molten steel to stay the method going.

The whole process is controlled to make sure there's a smooth flow of molten steel through the tundish.

Further, the pollutants and slag are sifted in tundish before they enter the shape. The entrance of the mold is crammed with inert gases to stop the reaction of molten steel with the gases within the environment like oxygen.

The molten metal moves swiftly through the mold and it doesn't completely solidify in it.

The entire mold is cooled with water that flows along the outer surface Typically, steel casting solidifies along the walls of the casting then gradually moves to the inside of the steel casting.

The metal casting moves outside the mold with the assistance of various sets of rollers.

While one bunch of rollers twist the metal cast, another set will fix it. This helps to vary the direction of flow of the steel slab from vertical to horizontal.

Fig.Continuous Casting Process

Equipment of Continuous Casting Process:

The essential equipment of a Continuous Casting machine are as follows

(i) Ladle turret alongside turret weighing system and ladle cover manipulator.

(ii) Tundish and Tundish car alongside Tundish weighing system, Tundish preheater, and dryer.

(iii) Mould and mold oscillation alongside mold level control and electromagnetic stirrer.

(iv) Secondary cooling subsist of strand cooling, strand containment, and guiding.

(v) Withdrawal and straightener.

(vi) Pinch roll and torch cut-off unit.

(vii) Dummy bar, dummy bar parking, and dummy bar disconnect roll unit.

(viii) Identification system, and.

(ix) Roller table and product discharge system.

• Ladle Turret: It is mounted at the built-up substantial base. It holds the steel overflowing scoops, which can weigh up to 300T. Through the spoon turret, the steel overflowing scoops are then again slewed into pouring and charging positions. This capacity guarantees the continuous activity of the Continuous Casting Machine. While one ladle is being exhausted, a full ladle is given on the opposite side.

• Tundish: The main function of the tundish is to be a steel reservoir between the steel teeming ladle and the mold. In addition to being a reservoir of liquid steel, the tundish is increasingly being used as a metallurgical reactor vessel to improve control of steel cleanliness, temperature, and composition.

• Mould: The mold is the heart of the Continuous Casting machine and the origin of many defects can be related to the phenomena taking place in the mold. Subsequently, the form marvels and control of them are of uncommon significance. The fundamental capacity of the form is to set up a strong shell adequate in solidarity to contain its fluid center upon passage into the optional splash cooling zone. Key item components are shape, shell thickness, uniform shell temperature dispersion, deformity-free interior and surface quality with insignificant porosity, and few non-metallic incorporations.

• Secondary Cooling: Commonly, the auxiliary cooling framework has involved a progression of zones, each liable for a portion of controlled cooling of the hardening strand as it advances through the machine, The showered medium is either water or a blend of air and water.

• Strand Containment: In Continuous Casting machines, the cast strand is needed to be upheld by rolls and guided from the vertical to the level plane. The control district is a vital piece of the optional cooling region. A progression of holding rolls contain the strand, stretching out across inverse strand faces. Edge move control may likewise be required. The focal point of this space is to give strand direction and regulation until the cementing shell is self-supporting.

• Bending and Straightening: Similarly imperative to abandon control and direction from the vertical to the flat plane are the inflexible and fixing powers. As rigid happens, the strong shell external span is under pressure, while the internal sweep is under pressure. The subsequent strain is dictated by the curve sweep alongside the mechanical properties of the steel grade being projected. In the event that the strain along the external span is unreasonable, breaks can happen, truly influencing the nature of the steel. These strains are commonly limited by joining a multi-point rigid interaction, in which the radii become continuously bigger to progressively fix the item into the level plane.

• Dummy Bar: Delivery and feeding of dummy bars into the mold, their separation from the cast section and removal after pulling through roller guides, and holding in the non-operating position are performed through uncommon machines, which are frequently furnished with unique helper instruments. Dummy bars can be fed into the mold in two days, namely, downwards and upwards.

Various Analytical Properties And Considerations of Manufacturing By Continuous Casting Process:

• Continuous casting manufacture is not quite the same as other metal projecting cycles, especially in the circumstance of the interaction. In other casting operations, the different steps to the process such as the ladling of metal, pouring, solidification, and casting removal all take place one at a time in sequential order. These steps are all occurring constantly and at the same time, in continuous casting manufacture.
• This process is used in commercial manufacture as a replacement for the traditional process of casting ingots.
• Piping, a typical issue in ingot make, is wiped out with the constant projecting interaction.
• Primary and synthetic varieties in the metal of the projecting, regularly present in ingots, have been dispensed with. When producing with the consistent metal projecting interaction, the projecting's material will have uniform properties.
• While utilizing consistent metal projecting assembling, the castings will set at multiple times the rate that a projecting sets during ingot creation.
• With less loss of material, cost decrease, higher usefulness rate, and unrivaled nature of castings, nonstop projecting assembling are regularly the decision over ingot creation.
• A continuous casting manufacturing process will take impressive assets and intending to start, it will be utilized in without a doubt, intense mechanical activities.

Advantages of Continuous Casting Process:

• With less loss of material, cost decrease, higher usefulness rate, and unrivaled nature of castings, nonstop projecting assembling are regularly the decision over ingot creation.
• The continuous cast material is consistently dense and homogeneous in structure, and therefore well suited for pressure applications.
• Straight, valid, and concentric item for high-velocity bar machines. Numerous providers keep up stock sizes for prepared accessibility to wholesalers and others requiring full-lengths.
• In the event that the shape is upgraded, the tidy-up stock needed on constant cast material is frequently not exactly that required for parts created with other projecting cycles.
• Continuous castings have an inherent advantage in mechanical properties over other methods because of the chilling and the excellent feeding of molten metal during solidification.
• Continuous castings perform well under pressure.

Limitations of Continuous Casting Process:

• Because of the impressive form cost and projecting machine set-up, it is uneconomical to consider the ceaseless cast technique for uncommon shapes or extraordinary amalgams in little amounts.

Applications of Continuous Casting Process: 

• A great age of continuous casting is done using cast steek Other metals that are continuous casting are copper, aluminum, grey cast irons, white cast irons, aluminum bronzes, oxygen-free copper, etc. Metals are cast as ingots for rolling expulsion or producing, and long states of the basic cross-area are given a role as round, square, hexagonal bars, and so on.

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