Dina Iron and Steel Ltd manufactures billets, wire rods, and TMT bars through various processes. Billets are produced through a two stage continuous casting process involving melting scrap and other alloys in induction furnaces before pouring the molten metal into a continuous casting machine. Wire rods are made by reheating billets and rolling them through grooved rollers. TMT bars also involve reheating billets and rolling, followed by quenching, self-tempering, and atmospheric cooling to impart strength and ductility. Quality control measures are applied throughout production.

1. Presented By:
Kumar Gaurav , B.Tech (3rd year)

2. Dina Iron and Steel Ltd. Was Incorporation on 23rd
September,1993.
Dina Iron & Steel Limited is well established company of east
India with its production plant located at Patna .
 They are the lead manufacturer of Billets , Wire Rod and TMT
bars.
The site is favourably located in terms of availability of raw
materials especially from mega manufacturers like
TISCO,Rourkela ,SAIL and Bokaro Steel Plant.

3. Sponge Iron and Scrap with alloys together are melted in four
Induction Furnaces
Billets go through chemical and physical testing in the well
equipped testing laboratory
Billets goes through reheating furnace then to pair of
grooved rollers through to four stands of Block mill and finally
to the coiler

4. 1.Wire Rods
2.TMT Bars
3.Billets

5. The company manufactures 5.5mm Wire rod.
The furnace oil or coal operated reheating furnace heats
up our in house manufactured billet and send it for rolling.

6. Thermo Mechanically Treated (TMT) bars are manufactured
dimensions ranging from 8mm to 25mm.
The treatment process has three successive stages
•Quenching
•Self- Tempering
•Atmospheric Cooling.

7. It manufactures square billets thorough continuous casting
machine which is a semi finished product.
Our manufactured billet goes thorough chemical analysis.
After passing the physical and chemical testing They are forward
our next manufacturing process “Rolling Mill”.

8. WIRE ROD MANUFACTORING
PROCESS:
Billet’s are heated to about 1200 degree centigrade in a Reheatin
furnace fueled either by Furnace oil, coal or Gas.
The Process of rolling wire rod is essentially hot deformation of
billet in stages.
As a 5.5 mm diameter wire rod has very large area to traverse,
ratio of heat loss in the process is rapid and rolling is to be carried
out fast.
The hot rolling processing involves passing the hot bar through th
grooves of the rotating paired rolls in a predetermined sequence

9. When the red hot bar leaves the last rolling stand of paired
grooved rollers it has to go through the tension releaser
Then it enters into the four stands of no twist block mill.

10. Billets are reheated into oil or coal fired reheating furnace.
These reheated mild steel billets are passed through successive pair of
grooved rollers “3 roughing, 4 intermediate, 2 finishing, 4 continuous”
respectively.
When the red hot bar leaves the last rolling stand it has to go
through the treatment process

11. •The treatment process has three successive
stages
Quenching - When the red hot bar passes through the last set of rolls
They go to the water cooling quenching box where series of water is
sprayed on hot metal. This rapid cooling procedure cools the outer
surface of the bar making it harder known as “Martensite”.
Self- Tempering-In this stage when the bar leaves the quenching
machine. The surface of the bar in the quenching stage was cooled but
the temperature of the core remains high. The heat from the core of
the bar flows to the surface of the bar “Martensite” which is cooler
heating up the quenched surface thus tempering the surface. The inner
core of the bar is austenitic.
Atmospheric Cooling-When the bar makes its way to the
cooling bed it is allowed atmospheric cooling. In this stage the
unchanged core of the bar austenite is transformed to ferrite-
pearlite. Ferrite – pearlite is ductile by nature.

12. These successive manufacturing stages give TMT bars the ultimate
combination of strength and ductility with enhanced bending, welding,
rust resisting ability which leads to easy application of TMT bars in
different types of engineering works.

13. The process of manufacturing Billets is a two stage process.
The first stage consists of feeding M.S. Melting scrap, Sponge
Iron, Pig Iron and other alloys in the induction furnace and then
melting it to a liquid state by applying electrical power.
The melted liquid is poured into a ladle.
The induction furnace / continuous casting machine section is a mostly
automated unit with manual operations at some places.

15. Induction furnace is an electrically run furnace mainly used for
melting metals
Induction furnaces are cylindrical, open-topped, tilt-able
refractory crucibles which is a melting container
Copper solenoid coil installed on the outside, around the side
wall are kept cool by water circulating from a special cooling
tower.
The refractory wall of the crucible is usually thin enough to achieve
good penetration of the electromagnetic field into the charge.

16. During induction, an electric current is passed through a metal
coil which creates a magnetic field.
When metal is introduced into the magnetic field, an electrical
current passes through the metal and causes it to heat. The heat
produced by the electromagnetic charge melts the metal.
The electromagnetic field stirs the melt well, and this is
beneficial for alloying. This stirring is essential to maintaining the
integrity of the metal.
After reaching desired molten stage & temperature small piles
of sponge iron is continuously introduced.
Formed floating slag is constantly removed during melting.
Now in second stage, the molten metal in the ladle is taken
to the continuous casting billet machine and is poured in it

17. Induction Furnace Diagram

18. Induction Furnace

19. Continuous Casting is the process where molten metal is
continuously casted into a semi finished product called billet.
Billets produced through continuous casting process is cost
effective and better quality with little or no chance of impurities.
Temperature is taken of the molten metal in the Induction
furnace with the help of disposable thermocouple.
Hot molten metal is poured into the ladle from Induction
furnaces.
The hot metal is transferred to a tundish from the ladle.

20. Metal is drained from the tundish into the mould tube.
The dimension of mould tube can vary, depending on the
desirable casting size.
Lubricant in form of powder or liquid is used in the mould tube
to prevent sticking,
Aluminum wire is continuously introduces in moderate amount
during casting as a good oxidizing agent and to remove
impurities
Solidification in continuous casting (CC) technology is initiated in
a water-cooled open-ended copper mould
The solidification process in the mould is completed in
secondary cooling zones using a combination of water spray
into a spray chamber exits the base of the mold into a spray-
chamber.

21. There are different types of casting machine. They have curved
apron casting machine.
Molds in a curved apron casting machine can be straight or
curved.
After exiting the spray-chamber, the strand passes through
straightening rolls and withdrawal rolls.
The strand is cut into predetermined lengths by traveling handheld
oxyacetylene torches or by mechanical shears.
Billets are piled in a horizontal vertical continuous order and is
marked by numbers commonly known as heat numbers
Casted Billets are cooled and then sent to the rolling mill for
rolling.

24. Continuous Casting

25. In order to keep manufacturing durable steel every raw material
like Sponge Iron, Pig Iron, different alloys used goes through
strict quality testing
Special care is taken throughout the process in order to maintain the
quality of the finished products
They use continuous casting process to manufacture .
Billets. Billets produced through continuous casting process is
better quality with little or no chance of impurities making their way
that may effect the strength and durability of the product.

26. The use of no twist block mill technology which helps in quality
production with:
•Smooth surface finish
•No variation in dimensions throughout the length of the wire rod
•Similar physical properties entire length of wire rod.

27. WEB RESOURCES:
TEXTUAL RESOURCES:
Apart from these resources, my own observance and cognizance has lead to the the successful
accomplishment of this presentation.
Manufacturing Process 1 P.N.Rao
Material science W.B. Callister
www.steel.org
www.slideshare.net
www.wikipedia.org