Presentation BASICS Continuous Casting

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GET TECHNICAL TRAINING MODULE

CONTINUOUS CASTING

STEEL

What is Steel ?

What are the applications of steel?- Type of Steel - By Composition- Type of steel – By Shape

What are the process route for producing steel?

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CONTINUOUS CASTING

STEEL - Applications

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CONTINUOUS CASTING

STEEL - Applications

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CONTINUOUS CASTING

STEEL - Process Route : Flat Products

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CONTINUOUS CASTING

Cold rolling mill

Annealing and surfacegalvanizing and improving

Hot rolling mill

Shears andfinishing equipment

Pickling

Reversingcold rolling

mill

CSP plant

STEEL - Process Route : Flat Products

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CONTINUOUS CASTING

STEEL - Process Route : Long Products

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CONTINUOUS CASTING

STEEL - Process Route : Long Products

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CONTINUOUS CASTING

STEEL - Process Route : Past & Present

SLABBING / BLOOMING MILL

SLABBING / BLOOMING MILL

SO

AK

ING

P

ITS

OA

KIN

G

PIT

Re-Heating Furnace

Re-Heating Furnace

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CONTINUOUS CASTING

Advantages of Continuous Casting :- Energy Efficient Process- Yield is much higher- Mass production of Semi-Finished product- Lower Operating Cost- Consistent Quality

Dis-Advantage - High Capital Cost

STEEL - Process Route : Past & Present

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CONTINUOUS CASTING

Basics of Continuous Casting

What is Continuous Casting

Transforms Liquid metal into Solid on Continuous basis. Water Cooled open ended copper mould Mould oscillates along axis of strand Dummy bar closes the mould from one end while start casting

and continuously withdrawn through segments. Along with D/bar, Partially Solidified Strand continuously

withdrawn. Core with liquid gradually solidifies as strand moves

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CONTINUOUS CASTING

PRODUCT RANGE

Slab Casting thickness 150 - 400 mmwidth 400 - 3,200 mm

Twin Casting thickness 100 - 350 mmwidth 300 - 1,575 mm

Medium Slab Casting thickness 90 - 150 mmwidth 300 - 3,050 mm

Thin Slab Casting thickness 40 – 70(90) mmwidth 790 - 1,680 mm

Billets

Rectangular min. 200 x 240 mmmax. 400 x 600 mm

Square min. 220 x 220 mmmax. 345 x 345 mm

Round dia. min. 100 mmdia. max. 600 mm

Beam Blank max. 1,119 x 500 x 132 mmmin. 243 x 170 x 73 mm

Square 76 - 215 mm

Slabs Blooms and beam blanks


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CONTINUOUS CASTING


Types of Continuous Casting Machines

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CONTINUOUS CASTING

Type of Caster

Advantages Dis-advantages

Vertical Casters

No deformation through bending and unbendingGood floatation of inclusions and oxides

Large overall heightsHigh Ferro static pressure Casting speed limited by lack of available length.

Curved type Caster with straight mould

Minimal hindrance of oxide float-out provided the vertical section is sufficiently long.

Early and considerable deformation of the shellHigher ferro static pressure than curved mouldLarge degree of straightening deformation.


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CONTINUOUS CASTING

Type of Caster

Advantages Dis-advantages

Curved type Caster with curved mould

Strand straightened only when shell is already relatively thick. Low overall height, low ferro-static pressure, simple withdrawal and straightening

Oxide or inclusion Floatation Is poor and defect related to sliver in the product is high.


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CONTINUOUS CASTING

Design aspects of Continuous Casting


Type of Product Tonnage Machine Length and Casting Speed Vertical Height of Mould Radius of Machine Roller Pitch Metallurgical Length

- Square Root Law

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CONTINUOUS CASTING

Continuous Casting Metallurgy

Solidification Process

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CONTINUOUS CASTING


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CONTINUOUS CASTING

Hot Ductility


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CONTINUOUS CASTING

Hot Ductility


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CONTINUOUS CASTING

Hot Ductility


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CONTINUOUS CASTING


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CONTINUOUS CASTING


Cleanness in Continuous Casting

Non-Metallic Inclusions Entrapment or Dissolve of Non desirable

gases

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CONTINUOUS CASTING


Secondary Metallurgy : Inclusion formation begins during precipitation de-oxidation with the

formation of endogeneous oxides. Control on Carry over Slag from EAF Removal of dissolve gases

Oxygen – Using De-oxidiser Hydrogen – VD Nitrogen – VD

Removal of Oxides by floatation

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CONTINUOUS CASTING


Caster : Re-Oxidation and Gases pick-up

During Teeming from Ladle to Tundish

During Pouring from Tundish to Mould

Non-Metallic Inclusion Clogging

Presentation BASICS Continuous Casting

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