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Group Steel
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1
TITLE : GROUP ASSIGNMENT
(HIGH TENSILE STEEL)
COURSE CODE : SKAA 2112
COURSE : CIVIL ENGINEERING MATERIAL
LECTURER : ABDULLAH ZAWAWI AWANG
NO NAME I/C NO. MATRIX NO.
1. AINIE MASTURAH BINTI
MUSBAH 850921-08-6218 SX143202KAWF04
2. NUR AZIZAH BINTI
SYAWIR 870610-10-5360 SX143240KAWF04
3. NABILAH BINTI JAFFAR 890227-23-5128 SX143317KAWF04
4. UMI AMIRA BINTI
KONGIT 870506-10-5336 SX143248KAWF04
Nur Azizah Binti Syawir Umi Amira Binti Kongit
Nabilah Binti Jaffar
Ainie Masturah Binti Musbah
TABLE OF CONTENTS
NO TITLE PAGE
1. INTRODUCTION
a) Mild steel
b) High tensile steel
1
1
2
2. PROCESS OF MANUFACTURE
Process Flow Chart (M.S. Bolts)
Process Flow Chart (H.T. Bolts)
3
4
5
3. MECHANICAL PROPERTIES OF HIGH TENSILE
STEEL
6
4. ADVANTAGES OF USING HIGH TENSILE STEEL 7
5. DISADVANTAGES OF USING HIGH TENSILE STEEL 8
6. USED / APPLICATION OF STEEL 9
7.
7.1
7.2
7.3
TYPE OF STEEL
Low carbon steel
Medium carbon steel
High carbon steel
9
9
10
10
8. ROLE ELEMENT IN STEEL 11
9. SURVEY POINT 12
10. DIFFERENCE HIGH TENSILE STEEL AND MILD
STEEL 13
11. CONCLUSION 14
12. REFERENCE 15
SKAA 2112 – CIVIL ENGINEERING MATERIAL
Nur Azizah Binti Syawir Umi Amira Binti Kongit
Nabilah Binti Jaffar 1
Ainie Masturah Binti Musbah
HIGH TENSILE STEEL
1. INTRODUCTION
Steels are a large family of metals. All of them are alloys in which iron is mixed with
carbon and other elements. Steels are called as mild, medium- or high-carbon steels
according to the percentage of carbon they contain, even though this is never greater than
about 1.5%. High carbon steel also called high tensile steel.
High-tensile steel is used for construction that requires the use of materials proficient of
treatment an immense amount of extending and carting without breaking. It must have a high
ductility and toughness to escape buckling or cracking, with a maximized grain modification.
There are two main kinds of steel. Plain carbon steel and alloy steel. Plain carbon steels
are divided into three main groups, low carbon steel also known as mild steel, medium
carbon steel and high carbon steel also known as high tensile steel.
a. Mild Steel
Mild steel, also known as plain-carbon steel, it the most common method of steel because
its price is relatively low while it provides material properties that are acceptable for many
applications. Low-carbon steel contains approximately 0.05–0.15% carbon making it soft and
ductile. Mild steel has a relatively low tensile strength, but it is cheap and easy to form;
surface hardness can be increased concluded carburizing.
Low-carbon steels contain less carbon than other steels and are easier to cold-form,
making them easier to handle.
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HIGH TENSILE STEEL
b. High Tensile Steel
Carbon steels which can successfully undertake heat-treatment have carbon content in the
range of 0.30–1.70% by weight. Amounts of sulphur make the steel red-short, that is, brittle
and crumbly at working temperatures. Manganese is a lot added to improve the hardenability.
Among the types of high tensile steel is a nut n bolt.
A manufacturing fastener contains a very wide range of items like nuts and bolts,
washers, studs, nails etc. Nuts and bolts consist a major link in the family of industrial
fasteners and are used by every industry. Nut and bolts are available in various shapes,
designs and sizes. Nuts and bolts are used for fastening purpose in industry. There are many
industries producing these nuts and bolts of various sizes. The alignment of materials controls
the quality of the bolts and nuts.
Nuts and bolts are classified by two ways:
Their uses
Shape of head
In terms of use, nuts and bolts are of some type. Larger diameter bolts, machine bolts,
stand bolts, joint bolts, foundation bolts and nuts etc. in terms of shape, bolt and nuts are
classified by head shape like hexagonal head, square head, round head, pan head, truss head
etc.
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HIGH TENSILE STEEL
2. PROCESS OF MANUFACTURE
The raw material used for manufacture of bolt is M.S. Rounds. As some of the rounds
available are rusty and not perfectly round and straight, it is necessary to make them round.
The rounds are pickled in the acid tanks, washed and drawn in a drawing machine. The
cleaned rod is fed into the cold heading machine. In the machine, one end of the rod is cut
into the desired length with cutting stroke and simultaneously the head formation takes at
another end. For the HT a bolt, forging is done on hot forging press. The pins are then
trimmed in the trimming machine. In quality bolts, the lower side of the head is also faced.
Threading is done in the thread rolling machines.
While manufacturing nuts, the hexagonal rod of desired size is procured and the nuts are
cut on the automatic nut-cutting machine. Cutter nuts blanks are drilled and tapped on the
nut-tapping machine. Finally, these are demurred in the polishing barrel.
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HIGH TENSILE STEEL
Process Flow Chart (M.S. Bolts)
Mild steel rod
Bolt cutting
Head making
Head trimming
Thread rolling
Polishing
Store/dispatch
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HIGH TENSILE STEEL
Process Flow Chart (H.T. Bolts)
Mild steel rod
Wire drawing
Bolt cutting
Forging
Trimming
Threading
Heat treatment (800oC – 900oC)
Tempering (400oC – 5000C)
Plating/Coating
Store/dispatch
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HIGH TENSILE STEEL
3. MECHANICAL PROPERTIES OF HIGH TENSILE STEEL
Some important characteristic features of the property profile are:
High wear resistance
High hardness
Excellent toughness / strength ratio
Good weldability
Improved weathering resistance
Good machinability
Good grain toughening resistance
For hardness, strength and toughness generally is used in the heat treated condition, the
tempering behaviour shall get a special prominence. The characterises dependence of the
hardness on the tempering temperature. Due to its adjusted contents of chromium and
manganese and in spite of the low carbon content, the steel shows a similar tempered
hardness as the higher alloyed cold work steel.
The through hardenability, which is mainly depending on the chromium content. High
strength level results in a high fatigue strength than the cold working. The durability strength
is a little bit lower than on the comparative steel. Without causing detrimental grain
coarsening effects on the properties, some higher needed hardening temperatures is possible.
Besides, fine grains are guaranteed up to highest carburizing temperatures. With this, the steel
is well suited for directnhardening too, which today is done from higher and higher
temperatures for reasons of economic efficiency.
Not least the machinability is an important property for a lot of applications. Welded in
the annealed condition but avoid when possible if hardened and tempered due to the effect on
the mechanical properties.
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HIGH TENSILE STEEL
4. ADVANTAGES OF USING HIGH TENSILE STEEL
The a many advantages of high tensile steel as follows:
a) High Strength
This means that the weight of structure that made of steel will be small.
b) Addition to Existing Structures
Example : New bay or even new wings can be added to existing frame buildings.
c) Lustre
It is shiny metal with a very attractive finish (architecture, cutlery and appliances).
d) Mallaeability
It can be rolled into thin sheets, rod or bar (roofing, structural) or forged into different
Shapes (gears or tools).
e) Conductivity
It can transfer heat and electricity.
f) Ductility
It can be stretched and drawn out into thin wires (wire fences) or pressed into
different shapes(auto body panels).A very desirable of property of steel in which steel
can with stand extensive deformation without failure under high tensile stresses i.e it
given warning before failure takes place.
g) Durability
It is long lasting material and resistant to wear ( machines aand equipment).
h) Toughness
Steel has both strength and ductility.
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HIGH TENSILE STEEL
5. DISADVANTAGES OF USING HIGH TENSILE STEEL
Although high tensile steel has all advantages as structural material, it also has many
disadvantages. For examples, steel columns sometimes cannot provide the necessary strength
because of buckling. Steel is one of the weaknesses in terms of buckling. Buckling failure is
the main characteristic of a steel. As most members are built in hot-rolled steel, the cross-
section is thin and the ratio of width / thickness great cause buckling easily occurs when the
compressive force is applied. However, buckling easily overcome if some of the design
considerations are taken.
Steel having high heat flow but low heat capacitance. this situation led to the strength of
steel decreases when exposed to temperatures of more than 400 °C and should be protected
from fire. in addition, the coefficient of thermal expansion for steel is also great. this problem
can be overcome by using a number of methods suitable fire protection as covering the fire
resistance of steel with materials such as concrete and the like. In addition, there are also
another weaknesses steel, especially the members exposed steel structure to be protected with
paint to prevent corrosion occurring.
The disadvantages of high tensile steel as follows:
Maintenance Cost
Steel structure are susceptible to corrosion when exposed to air, water and humidity.
They must be painted periodically.
Fireproofing Cost
Steel is incombustible material, however, its strength is reduced tremendously at high
temperatures due to common fires.
Susceptibility to Buckling
For most structure, the use of steel columns is very economical because of their high
strength- to- weight ratios.
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HIGH TENSILE STEEL
6. USED / APPLICATION OF STEEL
Steel is obtained through carbon reducing operations.
Carbon steel is an alloy of iron and carbon.
Amount of carbon within the lattice determines the properties of the steel.
Alloys containing less than 0.008 % carbon are classed as irons. Steel has a carbon
content less than 2.0 %
Normally, Mn and S are added to steel during production
If elements other than Mn and Si are added ⇒ alloy steels
If elements like Cr and Ni are added ⇒ stainless steels
7. TYPE OF STEEL
1) C ≤ 0.25 % ⇒ mild steel, low carbon steel (structural steel is in this category)
2) 0.3 % ≤ C ≤ 0.6 % ⇒ medium carbon steel, carbon steel
3) C > 0.6 % ⇒ high carbon steel
7.1 Low Carbon Steel.
Contain less than 0.25%Carbon
Not very responsive to heat treatments.
Soft, weak, tough and ductile.
This materials are easily Machin able, weld able, not expensive.
These are arguably produced in the greatest quantities than other alloys.
Carbon present in these alloys is limited, and is not enough to strengthen these
materials by heat treatment; hence these alloys are strengthened by cold work.
Their microstructure consists of ferrite and pearlite,
These alloys are thus relatively soft, ductile combined with high toughness.
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HIGH TENSILE STEEL
7.1.1 Uses As:
Typical applications of these alloys include: structural shapes, tin cans,
automobile body components, buildings, etc.
7.2 Medium Carbon Steel:
Contain 0.25-0.60 wt. % carbon.
Can be heat-treated but only in thin sections.
Stronger than low-C steels but less ductile and less tough.
Good wear resistance.
These are stronger than low carbon steels. However these are of less ductile
than low carbon steels.
Alloys can be heat treated to improve their strength. Usual heat treatment
cycle consists of quenching, and tempering.
7.2.1 Uses As:
Typical applications include: railway tracks & wheels, gears, other machine
parts which may require good combination of strength and toughness.
7.3 High Carbon Steel:
Contain 0.60 -1.4 wt. % Carbon.
These are strongest and hardest of carbon steels, and of course their ductility is
very limited.
Almost always used in tempered condition.
Especially wear resistant.
Form hard and wear resistant carbides with alloying elements.
These are heat treatable, and mostly used in hardened and tempered
conditions.
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HIGH TENSILE STEEL
7.3.1 Uses As:
Thus these are used for tool application such as knives, razors, hacksaw blades, etc.
With addition of alloying element like Cr, V, Mo, W which forms hard carbides by
reacting with carbon present, wear resistance of high carbon steels can be improved
considerably.
8. ROLE ELEMENT IN STEEL:
Chromium makes the alloy hard and increases the wear and corrosion resistance
of steel. Steels containing more than 4 percent chromium are called stainless
steels.
Sulfur is added to aid in machinability of the steel.
Silicon is added to improve the electrical, mechanical, and thermal characteristics.
Nickel is added to increase the toughness and strength.
Vanadium is added to increase the strength.
Tungsten is used to produce tool steels that will maintain a cutting edge at high
heat.
Aluminum helps to provide a hardened surface.
Molybdenum tends to increase the hardness and the endurance limits of steel.
Oxygen forms iron oxide which is not desirable.
Phosphorus is found in all steels. When present in high percentages it is
considered an impurity. At low percentages it improves machinability.
Carbon added to iron changes the physical properties. The amount of change is
directly proportional to the amount of carbon added to the iron.
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HIGH TENSILE STEEL
9. SURVEY POINT
Iron and steel are both hard and strong, and are commonly found in construction
(i.e. Bridges and buildings).
A disadvantage of iron is that it tends to rust. Although most steels will also rust,
they can be formulated to be rust free.
Plain carbon steels and cast irons are used in low cost, high strength applications
where weight and corrosion are not a problem.
Stainless steel or galvanized steel are used where resistance to corrosion is
important.
Aluminum alloys and magnesium alloys are used for applications where strength
and lightness are required.
Nickel-based super alloys like Inconel are used in high temperature applications
such as turbochargers, pressure vessels, and heat exchangers.
Casting - molten metal is poured into a shaped mold.
Forging - a red-hot billet is hammered into shape.
Rolling - a billet is passed through successively narrower rollers to create a sheet.
Extrusion - hot and malleable metal is forced under pressure through a die, which
shapes it before it cools.
Sintering - a powdered metal is compressed into a die at high temperature.
Machining - lathes, milling machines, and drills work the cold metal to shape.
Fabrication - sheets of metal are cut by a variety of methods and bent into shape.
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HIGH TENSILE STEEL
10. DIFFERENCE HIGH TENSILE STEEL AND MILD STEEL
HIGH TENSILE
STEEL
NAME HIGH TENSILE STEEL MILD STEEL
Composition Low carbon steel
Nickel
Chromium
0.15 to 0.30% carbon
Properties Very strong
Very tough
Tough
High tensile strength
Ductile
Uses Gears
Shafts
Engine parts
girders
plates
nuts and bolts
general purpose
Advantage Less malleable and
harder
Corrosion resistant
Brittle
High stiffness
can be further strengthened
through the addition of
carbon
Less brittle
Easily welded
Disadvantage low tensile strength
not particularly strong and
is expensive
Poor resistance to corrosion
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11. CONCLUSION
In general high tensile steel, an alloy of carbon mixed with iron, is one of the most
common industrial metals used throughout the world. Steel is rated for many kinds of
strength; tensile strength is a measure used by structural engineers to determine how much
force it takes to stretch something until its cross sectional area narrows. If ever pulled taffy
until it narrows, it performed the basic tensile strength test. Tensile strength is measured in
force per square meter, or Pascal in the metric system.
In construction now, must take a some several consideration when choose
construction material such as ultimate strength, sustainability, fire resistance, addition to
existing structures, conductivity and many more. Therefore, high tensile steel is the good
material as structural in construction.
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12. REFERENCE
www.assakkaf.com
Advantage-environment.com
www.tscforum.org
http://www.design-technology.org/CDT10metalsproperties.htm
http://www.processindustryforum.com/article/advantages-disadvantages-metals-
commonly-used-manufacturing
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