This training report summarizes production, workshop, and quality control processes at an Egyptian steel factory. It discusses the steel grades used, reheating furnace operations, rolling processes across 22 stands to produce wire rod and rebar, workshop functions including CNC machining, and quality control procedures for inspecting billets and final coil products. Key points covered include maintaining billet temperature below 723°C for magnetic transport, 14 burners in the reheating furnace heating billets to 1230-1250°C, and inspecting billets for surface defects like pinholes, slag, and cracks that could affect the rolled product.

1. Training Report
Production, Workshop & Quality control
By:
Amr Mansour
Hassan Ibrahim
Mohamed Sayed
Mahmoud Zakariya
Mahmoud AbdelRahman
2015
Alexandria
Egyptian steel
8/27/2015

2. Production
The steel grade of the billets which we use :
Important note:
The billet temperature must be below 723◦c to remain its magnetic
characteristics to transport it to the furnace by the magnetic winch
according to the iron carbon diagram:
The alloy remains ferrite (BCC) crystal structure below 723˚c to conserve its
magnetic characteristics
and above this temperature it will be Austenite (FCC) which doesn't have
magnetic characteristics.

3. Reheating furnace:
Reheating furnace in plant is divided to 3 parts with 14 burners :
 Preheatig
 Heating
 Soating
 There are 14 burner in the furnace
The billet is outing from furance at around 1230 ° C to 1250˚c .
There are 22 rolling steps to make 8mm wire rod and there are two
extra rolling stands to make it 6mm .
Roughing : from 1 to 8
Intermediate: from 9 to 14
Finishing: from 15 to 22

4. Note:
Hot rolling temperature must be above 850˚c, below it it will be cold
rolling and the stresses will maximize over the stands
PGV (mono block )
High speed rolling (32m/sec)
Rolling technology
Fundamental principles of metal rolling process
Rolling process:-
The process of shaping metal and alloys
into the semi-finished or finished condition by
passage between rolls is known as rolling.
The rolls rotate in opposite directions, one counter –clockwise and the other
clockwise.
Rolling involves plastic deformation of metal in which the thickness of the
strip is reduced and the length and width are increased.
DEFINITIONS
Draft or Draught:-
Draft is simply a reduction in thickness and can be either direct
draft or indirect draft.
-Direct Draft is a reduction made horizontally between
the rolls
-
-Indirect Draft is a reduction made at an angle to the
roll barrel
• The difference between the initial and final
thicknesses of the strip is called absolute draught
H = H1- H2
Elongation:-
Is the increase in bar length after being drafted.
Is around 70 %
The difference between the final and initial lengths

5. Is called the absolute elongation
L = L2 – L1
* The coefficient of elongation, i.e. the ratio of the length of the
metal after rolling to its initial length
Spread:-
Is the lateral or sideways movement of stock.
Is around 30 %
The difference between the final and initial widths
Is called the absolute spread
B = B2 – B1
Spread :- If we assume the same volume of material
enters and leaves the stand rolls, then the reduction in
thickness must be allied to an increase in width and length. The increase in
width is termed spread and it is generally around one third of the draft, but
the exact amount is determined by the following factors;
1- Temperature The hotter the material the less spread.
2- Chemical composition The higher the carbon the more spread.
3- Roll diameter The larger the roll the greater the spread.
4- Speed The higher the speed the less spread.
5- Pass shape some passes restrict spread while others
have zero control, and so flat rolls
(no pass groove) will have greater spread
The Angle of Bite and the Arc of Contact:
The Angle of Bite is the angle formed from the point
of contact
of bar entry to a perpendicular line through the
roll.Consider
30‫؛‬ as absolute maximum, and 22‫؛‬ as a general angle
for
smooth bite.
The Arc of Contact is the arc formed by the angle of
bite.
The larger the roll diameter the smaller the angle of bite
Speed control system:-
Modern continuous mills have a speed control system for
control and continuous adjustment of individual stand speeds.

6. 1- tension control system:-
In the roughing and intermediate stands
2-loop control system :-
In the finishing stands, between each two stands
( the volume of steel going through each stand must be
the same to avoid tension or compression.)
inference important :-
A1 V1 = A2 V2 = An Vn = Constant
Constant = Area (mm2) x speed (m/sec)
Speed control system
1- tension control system :-
“push- pull “ conditions :-
For continuous rolling:-
volume flow must be balanced Speed and
/or areas
must be correctly designed and adjusted to
achieve this i.e.
Area 1 * speed 1 = area 2 * speed 2 = area
3 * speed 3
Compression between two stands :-
volume flow out of first stand is greater
than can be
accepted by second stand loop forms and
continues
to grow
Tension between two stands:-
Volume flow delivered by first stand is less
than is

7. required by the second stand bar is pulled between stands
and will neck down and pull apart if tension is
severe enough
2-loop control system :-
Important note:
Having said this, one very important point,
if adjustments are made to loopers or any
other equipment then the product must be
checked after each adjustment. So make
your adjustments slowly, one by one, and check after each adjustment.
Fail to do this and one day you will roll scrap.
Rolls Materials Types
There are three types of materials used to made mill rollers
1- iron rollers
2-steel rollers
3-carbides rollers
1- Indefinite chill rolls - or grain-iron, these are a low cost roll, versatile
and would be found in slabbing mills, plate mills,roughing stands,
intermediate stands and finishing stands of section mills
2- Double poured rolls - (sometimes called composite, although this leads
to misunderstanding with the carbide composites) are cast in two stages
with an alloyed iron barrel surface for hardness and an unalloyed core for
toughness, these rolls are to be found in strip mills and plate mills.
3- Definite chill rolls - an older type of roll with limited surface depth, still
in use in the shallower grooves of the finishing stands of rod and bar mills
4- Nodular iron rolls or spheroidal graphite – have great resistance to fire
cracking and distortion with good pass life, the general applications are
throughout the mills of rod, bar and small sections

8. Steel Rolls
Steel rolls have high strength and resistance to deflection, the types of steel
rolls available are:
1- Cast steel rolls - used where strength and toughness are the main
requirements. The surface of cast steel rolls is prone to break-up and local
distortion. Cast steel rolls may be found as back-up rolls in four high mills,
blooming and slabbing mills, large section mills and billet mills
2-Forged steel rolls - provide greater strength, hardness and wear resistance
than cast steel but are more expensive. Forged steel may be found in
blooming and slabbing mills, cold strip mills.
3- Steel base rolls - regarded as cast steel rolls although the carbon content
places them between a steel roll and an iron roll. They are manufactured in
the same way as a conventional cast steel roll but are usually alloyed. In
certain applications their characteristics are similar to Indefinite chill iron
rolls. Steel base rolls are to be found in large structural and section mills.
Carbide Rolls
Carbide rolls are in fact a compound of tungsten carbide with a binder or
cement normally of cobalt. This technology involves heating (sintering) and
compressing fine powdered particles until all porosity is eliminated and the
particles are fused together under extreme pressure. The final product is a
permanently compressed shape of superior mechanical composition, very
hard with a very high resistance to wear, (a carbide roll pass will outlive a
cast iron roll pass to the order often to one).

9. GUIDES
Guides are considered the very heart of a rolling
process. They are probably the most significant
factor in adjusting and control in the rolling
process. Every stand is consisting of entry guide,
mill roll and exit guide.
GUIDES TYPES
There are two main types of guide
1- Entry guides:-
The entry guide responsible to receive the bar that is coming from previous
and ensure enters to mill roll without any deviation
2- Exit guides:-
The exit guide delivery the bar to the next stand without any deviation too
and so on
1-Entry guide types
1- Static or friction entry guide:-
These types used to receive the bar section such as box or diamond or square
or round shape
2-Roller entry guide:-
These types used to receive the bar section
such as oval or former shape
And there are three types of roller entry guides
1- Single pair roller guide (SR) 2-double pair
roller guide (DR)
This type consist of this type consist of two
rollers four rollers
2-Exit guide types
1- Static or friction exit guide:-
The static guide shape depends on the metal stock and roll pass for stand.
There are three types:

10. 1- Box exit static guide: such as used in roughing mill
Products
There will be two products in this plant after constructing the rebar line
soon:
1- Wire Rod:
Wire rod are small profiles including ordinary low carbon steel wire rods,
welding rod, blasting line with the rod, threaded rod straightening and
quality wire rod.
Common wire rod is mainly used for construction, wire drawing, packaging,
welding and manufacturing bolts, nuts and rivets.
2- Rebar:
The rebar is commonly used in reinforced concrete and reinforced
structures. It is usually formed from high carbon steel, and is given ridges
for better mechanical properties into the concrete.
It is widely used in various constructions, especially for large, heavy, light
thin and high-level construction. It's an important
material.
* The production of the factory is 300,000 ton/year

11. Workshop
1-the main function of workshop is to manufacture all required mechanical
components of spare parts of mill machine.
2- for periodic turning of corroded rings to re-use it again in rolling
operation.
3-to return rollers of roller guides.
4-fabrication works that required inside the plant.
Definition:
Computer Numerical Control (CNC) is one in
which the functions and motions of a
machine tool are controlled by means of a
prepared program containing coded
alphanumeric data. CNC can control the
motions of the work piece or tool, the input
parameters such as feed, depth of cut,
speed, and the functions such as turning
spindle on/off, turning coolant on/off.
remachined rings
Grinding CNC for tungsten carbide with electroplated diamond grinding wheel

12. general turning machinig
Directions
Mandrel to fix work piece

13. Holder and turning insert
The methods of manufacture in CNC
1-write G-code program for simple works
2- use cycles inside CNC control for more complex work piece
3-CAD-CAM software for complex geometry work piece
Applications:
The applications of CNC include both for machine tool as well as non-
machine tool areas. In the machine tool category, CNC is widely used
for lathe, drill press, milling machine, grinding unit, laser, sheet-metal
press working machine, tube bending machine etc. Highly automated
machine tools such as turning center and machining center which
change the cutting tools automatically under CNC control have been
developed. In the non-machine tool category, CNC applications
include welding machines (arc and resistance), coordinate

14. measuring machine, electronic assembly, tape laying and filament
winding machines for composites…. Etc.
Open Loop Control Systems :
The open-loop control means that there is no feedback and uses
stepping motors for driving the leadscrew . A stepping motor is a
device whose output shaft rotates through a fixed angle in response
to an input pulse.
Open loop control system
Closed-loop Control Systems:
Closed -loop NC systems are
appropriate when there is a force
resisting the movement of the tool/work piece .Milling and turning are
typical examples. In these systems. The DC servomotors and
feedback devices are used to ensure that the desired position is
achieved.
The feedback sensor used is an optical encoder. The encoder
consists of a light source, a photo detector, and a disk containing a
series of slots. The encoder is connected to the lead screw.
Closed-loop control system

15. PART PROGRAMMING FOR CNC:
we will describe how the part programmers execute manually the part
programs. A part programmer must have an extensive knowledge of
the machining processes and the capabilities of the machine tools
First, the machining parameters are determined. Second, the optimal
sequence of operations is evaluated
.Third, the tool path is calculated
.Fourth, and a program is written.
Sequence Number, N:
Consisting of typically three digits, its
purpose is to identify the specific
machining operation through the block
number particularly when testing a part
program.
Preparatory Function, G:
It prepares the MCU circuits to perform a specific operation. The G-
codes (some) are shown in the Table 1 implies incremental mode of
operation
*G codes used in CNC systems.
Table: 1 Preparatory commands (G-code)
G00 Point-to-point positioning
G01 Linear interpolation
G02 Clockwise circular interpolation
G03 Counter-clockwise circular interpolation
G04 Dwell
G05 Hold
G33 Thread cutting, constant lead
G40 Cancel tool nose radius compensation
G41 Tool nose radius compensation - left
G42 Tool nose radius compensation - right
G43 Cutter length compensation
G44 Cancel cutter length compensation
G70 Dimensions in inches
G71 Metric dimensions
G90 Absolute dimensions

16. G91 Incremental dimensions
G92 Datum offset
Dimension Words
1 . Distance dimension words, X,Y,Z
2 . Circular dimension words, I,J,K for distances to the arc center
3 . Angular dimensions, A,B.C
Spindle speed, S
Programmed in rev/min, it is expressed as RPM or by a three-digit
code number that is related to the RPM.
Miscellaneous Function, M
Consisting of two digits, this word relates to the movement of the
machine in terms of spindle on/off, coolant on/off etc shown in Table
2
Table: 2 Miscellaneous commands (M-code)
M00 Program stop
M01 Optional stop
M02 End of program
M03 Spindle start clockwise
M04 Spindle start counter-clockwise
M05 Spindle stop
M06 Tool change
M07 Mist coolant on
M08 Flood coolant on
M09 Coolant off
M10 Clamp
Mll Unclamp
M13 Spindle clockwise, coolant on
M14 Spindle counter-clockwise, coolant on
M30 End of tape rewinds.

17. Quality Control
Steel billet quality is one of the important factors affecting the quality
of rebar or coils that are produced in the Egyptian steel factory
because a small surface defect of a billet will be elongated during the
rolling and becomes an extensive product defect, requiring a
considerable cost for conditioning and fixing.
In the factory the function of the quality control department mainly
concerns in the billet as the initial source of the product and the coils
which are the final product of the factory.
For the Billet
The inspection of the billet has many
stages of inspection to insure that the
billet has the minimum defects with
which it can work and it's also inspected
by the chemical analysis test……
Here are some of the expected defects
that we may encounter in the billet and
their causes

18. Defect Possible causes Possible effects on
rolled product
Surface Minor
Pinholes
 Insufficient steel
deoxidation
 High content of
gas in the steel
(O,N,H)
 Excessive
amount of
casting oil
 Long and very
superficial
cracks on wire
rod
 Defects on
cold headed
product
Very small
pin holes
 Use of too much
lubrication oil in
the mold
 Very minor
influence on
hot rolled
product
Surface slag
>5mm
 Too much slag in
the steel
 Trapping of
products from
deoxidation
 Trapping of
products from
refractory
erosion
 Mn/Si ratio lower
than 2.5
 High alumina
content in the
covering powder
 In correct
distribution of
 Clearly visible
cracks and
fracture
 Overlapping
containing slag
 Steel sections
with outer
edges not
completely
formed

19. covering powder
 Sudden and
consistent steel
level in the mold
 Excess of Al wire
feeding in the
mold
Surface slag
<5mm
 Not much slag in
the steel
 Excess of
Aluminium wire
feeding in the
mold
 Mn/Si ratio very
low
 Secondary
oxidation
 Trapping of
covering powder
 Cracks of
various
dimensions
according to
slag particle
dimensions
Imperfect surface
Transverse
cracks at
the corner
 Deformed mold
tube
 Excess of mold
tapering
 Deposits on
external mold
surface tube
 Low hot
elongation of
steel (low Mn/Si
ratio)
 High steel
temperature
 High cooling of
the bar
concentrated in a
small area
 Irregular
oscillation
 Incorrect mold
 Large cracks
on the surface
 Rough surface
especially on
wire rod
 Possibility
breaking-off of
the bar during
hot rolling

20. lubrication
Longitudinal
cracks
 Worn mold tube
 Too large corner
radius in the
mold tube
 Excess of mold
cooling or
uneven mold
cooling pattern
 Too high steel
tapping
temperature
 Misalignment of
foot rollers or
guide and sprays
 Long and deep
surface cracks
Folding and
cold welding
 Worn or
deformed mold
tube
 Mold lubrication
not suitable
 Excess of slag in
the steel
 Low steel
tapping
temperature
 Low casting
speed
 Cracks and
laps
 Danger of
breaking-off of
the bar during
hot rolling
Healed
breakouts
 Worn or
deformed mold
tube
 Defective mold
lubrication
 Uneven mold
cooling
 Excess of slag in
the steel
 High steel
tapping
temperature
 Consistent
surface
defects

21.  Steel stream
from tundish not
well centred to
the mold
Aluminium
surface
deposits
 Wrong position
of the aluminium
wire feeding in
the mold that will
result in a
concentration of
the product at
the mold face
 Defects of the
surface
Transversal
cracks at
the bent
billet
surface
 Steel analysis as
high content of
the impurities
such as
Pb,Cu,Zn,Sb,S,P
 Problems
during rolling
that can be
overcome by
increasing the
length of the
head and tail
cropping
Heavy
oscillation
marks
 Low carbon
content in the
steel
 Excess of mold
tube tapering
 Mold oscillation
stroke too large
 Wrong ratio
between
oscillation
frequency and
casting speed
 Irregular
oscillation
 Mold lubrication
not correct
 Very seldom
the oscilation
marks will
cause surface
defects on
rolled products
 Sometimes it
can result in
very small
cracks on the
wire rod
surface
Longitudinal
facial cracks
 Worn mold tube
 Primary cooling
not uniform
 Longitudinal
consistent
cracks

22.  Incorrect(not
centred) steel
stream position
in the mold
 Incorrect
alignment of
mold tube with
foot rollers
 Difficulties
during hot
rolling
Transversal
corner
cracks
 Bending and/or
straightening of
the bar at too low
temperature
 Insufficient mold
lubrication
 Sudden liquid
steel level
variation in the
mold
 Deep
transversal
cracks
 Difficulties
during hot
rolling
Transversal
facial cracks
 Excess of
cooling in the
mold
 Sticking of the
bar solidified skin
to the mold face
 Excess of
cooling in the
secondary
spraying system
 Difficulties
during hot
rolling with
possibilities of
bar breaking
off
Longitudinal
depressions
 Worn mold tube
 Incorrect
alignment
 Not uniform
primary cooling
 Covering powder
not suitable or
badly distributed
 Under skin
cracks at 5
mm depth may
cause serious
cracks on hot
rolled bar
Transversal
depression
 Lack contact
between
solidified skin
 Under skin
crack can
cause serious

23. and mold walls
 Not uniform
lubrication
 Excess of mold
cooling
 Sudden liquid
steel level
variation in the
mold
defects in the
rolled bar
Surface
scratching
and roll
marks
 Jammed guide
rolls
 Rolls not
correctly aligned
 Other
obstructions in
the guide rolls
 Normally no
effect on rolled
product
False wall  Interruption of
the steel flow
from the tundish
 Danger of hot
rolled product
breaking-off
during rolling
Plating  Low steel
tapping
temperature
 Surface
defects
False face  Lack of mold
lubrication
 Mold powder not
suitable
Spreading
of surface
particle
 Spreading of
steel stream fro,
the tundish
 Surface
defects
Surface
trapped slag
 Product coming
from deoxidation
or refractory
material tundish
covering powder
or mold covering
powder not
suitable or badly
distributed such
 Surface
defects

24. products
entrapped in the
skin formation
area are drawn
to the mold side
walls
Internal
defects
Blow holes  Not appropriate
steel deoxidation
 The blowholes
can expand
during rolling
causing cracks
on rolled
products
Star cracks  Too high or
irregular
secondary
cooling
 Problems in
the hot rolled
bar used for
hot/cold
pressing
Internal
cracks
 Steel analysis
with S higher
than 0.02% and
C between 0.17
and 0.25%
 Non uniform
primary cooling
 Deformed mold
tube
 Irregular cooling
at the mold exit
 High steel
tapping
temperature
 Defects on the
hot rolled
products when
the crack is
not deeper
than 5 mm
Diagonal
cracks
 Not uniform
primary cooling
or at the mold
exit area
 Guide rolls not
aligned
 Cracks in the
sub skin area
up to 5 mm
Can create defects
on hot rolled
products

25.  Rhombodity
higher than
5% can create
problems on
hot rolling
Cracks due
to uneven
cooling
 Not uniform
primary cooling
 Not uniform
secondary
cooling
 Not correct
alignment
between mold
and guide rolls
 Too high steel
tapping
temperature
 Subsurface
cracks can
cause defects
on hot rolled
bar
 Internal cracks
may have no
negative effect
on hot rolled
bar
And here are some of these defects that we could record during our
training
For the coils
Heavy
oscillation
marks
More bending
Scratches

26. For the coils:
In the factory the inspection of the coils mainly
concerns to the mechanical properties and the
dimensions measurements.
The mechanical properties includes the yield and
tensile strength, bending and elongation
Test method
Test specimens are
accurately measured before
testing .specimen are then
fitted into the jaws of the
tensile testing machine and
subjected to a continually
increasing tensile force until
the specimen fracture. The
tensile strength (Rm) is
calculated by dividing the
maximum load by the cross
sectional area of the test
specimen –measured before
At the bent billet
surface near the
surface cut

27. testing.
The dimensions must be equivalent to the required dimensions with a
maximum tolerance of +0.3 and -0.3
These coils are used Concrete Reinforcement with dimensions start
from 5.5 mm to 12mm of low carbon steel in order to achieve the
Egyptian standard specifications (ES262/2009) grade B240B-P
Suggestions for quality department
 The quality department is restricted only on billet and the coils
which is considered to have few functions
 We have to expand the quality control functions to include the
whole factory especially the rolling mills and other equipment so
that we can minimize the malfunctions as much as possible and
predict it before its occurrence.
 For the billet and coils there are only few tests that are used as
mentioned above such as chemical analysis , mechanical
properties and dimensions measurements
 We have to introduce various testing methods such as Non
Destructive Testing and Destructive Testing which will help in
the prediction of defects before malfunction

28. At the end of our training ... it was an honor
for us to spend a month in such a promising
factory with the help of the engineers who
dedicate their time and effort for our benefit
hoping to develop this factory which will remain
in our memories and minds as the place where
we gained great experience and skills.
…..