T H E A L L O Y I N G E L E M E N T S A N D T H E I R E F F E C T O N T H E P R O P E R T I E S

O F S T E E L

• BSME01133079 FAIZ JAWAID

• BSME01133069 BILAL ASHAR

• BSME01133042 ASAD BAJWA

WHAT IS ALLOY?

Alloy is the metal made by the combination of two or more metals

or elements combined to attain certain chemical or mechanical

properties

DIFFERENCE BETWEEN

ALLOY AND COMPOSITE

A Brief Description

Alloy is a mixture of two or more elements where at least one of them

is metal.

Steel is an example for alloy. It is made up of iron and carbon.

Composite is a material made out of two or more constituent materials

which are chemically or physically different.

Concrete is the composite material typically consists of gravels held

with a matrix of cement

A BRIEF HISTORY OF

ALLOYS

Historically, the earliest alloys created by man was brass, a simple

alloy of copper and zinc known to be in use from as early as 3000 BC

King Croesus of Lydia during the years 560-546 BC desired and

developed the first official government coinage system using a

naturally occurring alloy of gold and silver, known as Electrum

ALLOY STEEL

Alloy steel is basically mixture of Iron and Carbon and other trace

elements (Silicon Manganese Sulfur etc)

Carbon %age in steel is about 0.12 - 2%

Carbon

Chromium

Silicon

Manganese

Nickel

Vanadium

ALLOYING ELEMENTS IN

STEEL

Molybdenum

Tungsten

Aluminum

Titanium

Boron

CARBON

Percentage range 0.12 - 2%

Increases hardness

Increases Strength

The basic metal, iron, is alloyed

with carbon to make steel and

has the effect of increasing the

hardness and strength by heat

treatment but the addition of

carbon enables a wide range of

hardness and strength.

CHROMIUM

Percentage range 0.5 - 18%

Increases hardenability of steel (0.5-2%)

Provides Corrosion Resistance (4-18%)

Chromium is added to the

steel to increase resistance

to oxidation. This

resistance increases as more

chromium is added.

'Stainless Steel' has

approximately 18%

chromium and a very

marked degree of general

corrosion resistance when

compared with steels with a

lower percentage of

chromium. When added to

low alloy steels, chromium

can increase the response

to heat treatment, thus

improving harden ability

and strength.

CHROMIUM PROTECTION

Percentage Range 0.2 – 2%

Increases Strength (0.2 – 0.7%)

Spring Steels (0.7 – 2% )

Improve Magnetic Properties (Higher Percentages)

SILICON

This metalloid improves

strength, elasticity, acid

resistance and results in

larger grain sizes, thereby,

leading to greater

magnetic permeability.

Because silicon is used in

a deoxidizing agent in

the production of steel, it

is almost always found in

some percentage in all

grades of steel.

The addition of 2% silicon changes the behavior of the steel drastically for

use in a katana. This spring steel is most commonly seen in application on

fencing foils where it needs to withstand a high degree of bend and still be

able to return to center.

SILICON USE

Percentage Range 0.25 – 1%

When combined with Sulfur Improves Brittleness (0.25-0.40%)

Increases Hardenability (>1%)

MANGANESE

Increases strength at high

temperatures by eliminating

the formation of iron sulfides.

Manganese also improves

hardenability, ductility and

wear resistance. Like nickel,

manganese is an austenite

forming element and can be

used in the AISI 200 Series of

Austenitic stainless steels as

a substitute for nickel.

Percentage Range 2 - 20%

Provide Toughness (2-5%)

Provides Corrosion Resistance (12-20%)

NICKEL

Nickel is added in large

amounts, over about 8%, to

high chromium stainless steel

to form the most important

class of corrosion and heat

resistant steels. These are

the austenitic stainless steels,

typified by 18-8, where the

tendency of nickel to form

austenite is responsible for a

great toughness and high

strength at both high and low

temperatures. Nickel also

improves resistance to

oxidation and corrosion

NICKEL APPLICATIONS

Nickel stainless steel alloy Environmental Protection Agency (EPA)

eliminates a stronger and thicker corrosion-

resistant.

Percentage Range 0 - 0.15%

Stable Carbides-Increase Strength While Retaining Ductility

Promotes fine grain structure (FGS)

VANADIUM

vanadium can produce

stable carbides that

increase strength at

high temperatures. By

promoting a fine grain

structure, ductility can

be retained.

high carbon high chromium die steel with added

carbon and vanadium for abrasion resisting

qualities.

VANADIUM USE

The first large-scale industrial use of vanadium

in steels was found in the chassis of the Ford Model

T, inspired by French race cars.(1927)

Percentage Range 0.2-5%

Stable Carbides

Inhibits Grain Growth

MOLYBDENUM

Found in small

quantities in

stainless steels,

molybdenum

increases

hardenability and

strength, particular at

high temperatures.

Often used in

chromium-nickel

austenitic steels,

molybdenum

protects against

pitting corrosion

caused by chlorides

and sulfur chemicals.

Percentage Range

Hardness at high temperatures

TUNGSTEN

Produces stable carbides and

refines grain size so as to

increase hardness, particularly

at high temperatures

Many high speed steels - those used in cutting and machining tools like saw blades - contain around 18

percent tungsten

Tungsten-steel alloys are also used in the production of rocket engine nozzles, which must have high heat

resistant properties.

TUNGSTEN USES

Percentage Range 0.95 – 1.30%

Increase ductility in steel alloys

commonly used in draw quality steels.

Helps in removing the dissolved oxygen from the

liquid steel. This process is known as killing.

ALUMINUM

ALUMINUM USE

Aluminized steel in different parts of

a car

Percentage Range

Improves Strength

Reduces martensitic hardness in chromium

steels

TITANIUM

Improves both

strength and

corrosion resistance

while limiting

austenite grain size.

At 0.25-0.60

percent titanium

content, carbon

combines with the

titanium, allowing

chromium to

remain at grain

boundaries and

resist oxidization.

TITANIUM USE

EOS has expanded its metal materials portfolio with EOS titanium Ti64ELI and EOS stainless

steel 316L.

EOS titanium Ti64ELI is a light metal alloy that is corrosion resistant and bio-compatible

Percentage range 0.001-0.003%

Powerful hardenability agent

BORON

A hardenability agent that improves

deformability and machinability. Boron is

added to fully killed steel and only needs

to be added in very small quantities to

have a hardening affect. Additions of

boron are most effective in low carbon

steels.

Hot-stamping boron-alloyed steels for

automotive parts

BORON USE

Thank You