group steel

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


Nabilah Binti Jaffar 1


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.





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.





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.





HIGH TENSILE STEEL

Process Flow Chart (M.S. Bolts)

Mild steel rod

Bolt cutting

Head making

Head trimming

Thread rolling

Polishing

Store/dispatch





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





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.





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.





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.





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.





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.





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.





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.





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





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.





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

http://www.assakkaf.com/

http://www.tscforum.org/

http://www.design-technology.org/CDT10metalsproperties.htm

group steel

Documents

hightensile steel

mild steel mild steel

alloy steel

application of steel

difference high tensile

types of high tensile

highcarbon steels

main kinds of steel