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SRI/ TM / 43 /I01/ R 01/ 08 JUL 2014

WELDING- TIG & ARC

Welding Definitions :

Welding is the joining of multiple pieces of metal by the use of heat and

or pressure. A union of the parts is created by fusion or recrystallization

across the metal interface. Welding can involve the use of filler material,

or it can involve no filler.SRI/ TM / 43 /I01/ R 01/ 08 JUL 2014Pg

SRI/ TM / 43 /I01/ R 01/ 08 JUL 2014Pg: Purpose:

To become more familiar with the welding process and its effects

on the material

To look at the changes in microstructure and the hardness in the Heat Affected Zone (HAZ)

Welding defects, their cause and preventative Measures

Industrial radiography techniques

SRI/ TM / 43 /I01/ R 01/08 JUL 2014Pg: What commercial and technological importance does welding have?

Provides a permanent joint

Weld joint can be stronger than parent material

( If the filler material has superior strength characteristics and proper

techniques are used)

Usually the most economical way to join components

Can be done in the field away from a factory

SRI/ TM / 43 /I01/ R 01/08 JUL 2014Pg:

SRI/ TM / 43 /I01/ R 01/08 JUL 2014Pg:

SRI/ TM / 43 /I01/ R 01/08 JUL 2014Pg: Type of Welding:

Arc Welding

Tig Welding

Arc Welding :

A fusion welding process in which the coalescence of the metals

is achieved by the heat from an electric arc between an electrode

and the work.

SRI/ TM / 43 /I01/ R 01/ 08 JUL 2014Pg:

SRI/ TM / 43 /I01/ R 01/ 08 JUL 2014Pg: Types of Arc welding :

Shielded Metal Arc Welding (SMAW):

An arc welding process that uses a consumable electrode consisting of a filler metal rod coated with chemicals that provide flux and shielding.

SRI/ TM / 43 /I01/ R 01/08 JUL 2014Pg: Gas Metal Arc Welding (GMAW):

Arc welding process in which the electrode is a consumable bare metal

wire and shielding is accomplished by flooding the area with gas.

SRI/ TM / 43 /I01/ R 01/08 JUL 2014Pg: Tig Welding & Gas tungsten Arc Welding (GTAW).

TIG welding is a process where melting is produced by heating

with an arc struck between a non-consumable tungsten electrode and the work piece. An inert gas is used to shield the electrode

and weld zone to prevent oxidation of the tungsten electrode and

atmospheric contamination of the weld and hot filler wire.

SRI/ TM / 43 /I01/ R 01/ 25 2014Pg: Manual TIG welding

Engineering Material:

The Engineering metals play an important role in an industry, because the

process of all manufacturing starts with the raw materials. The materials, mainly used in actual practice may be broadly divided.

Metels MetalsFerrous Metals Non- Ferrous MetalsSRI/ TM / 43 /I01/ R 01/ 08 JUL 2014

SRI/ TM / 43 /I01/ R 01/ 08 JUL 2014Pg: Ferrous Metals :

The metals, which contain iron as their main constituent, are calledFerrous Metals. The various ferrous metals used in industry are

Pig Iron ,Cast Iron ,Wrought Iron and Steel

Non-Ferrous Metals :

The metals, which contain a metal other than iron as their main constituent, are called Non-Ferrous Metals. The various Non-Ferrous metals used in industry are

Aluminum , Copper , Zinc , Brass

SRI/ TM / 43 /I01/ R 01/08 JUL 2014Pg: Steel:

Steel is the generic term for a large family of Iron-Carbon alloys, which are malleable, within some temperature range, immediately after solidification form the molten state. The principle raw materials used in steel making are

Iron ore, Coal, and Limestone

Carbon Steel :

Is steel that owes its distinctive properties chiefly to the carbon is contains. A steel qualifies as a Carbon Steel while it contains the following materials at the rated percentage.

Manganese - 1.65 % (maximum)Silicon - - 0.60 % (maximum)Copper - - 0.60 % (maximum)

SRI/ TM / 43 /I01/ R 01/ 08 JUL 2014Pg: CLASSIFICATION OF CARBON STEEL :

Low Carbon Steel

(Carbon-0.05 To 0.25 %)

Medium Carbon Steel

(Carbon-0.30 To 0.55 %) High Carbon Steel

(Carbon-0.60 To 1.30 %)

SRI/ TM / 43 /I01/ R 01/ 08 JUL 2014Pg: Alloy steels:

Is steel that owes its distinctive properties chiefly to same element or

elements other that carbon, or jointly to such other elements and carbon.

Alloy steels posses high yield point and high strength. They are more

stronger, tougher and fatigue resistant than carbon steel.

Classification of Alloy Steel:

Low Alloy Steel

Medium Alloy Steel

High Alloy Steel

SRI/ TM / 43 /I01/ R 01/ 08 JUL 2014Pg: Low Alloy Steel:

Alloy steels contain one or more alloying agents to improve

mechanical and corrosion - resistant properties over those to carbon steel.

A typical low - alloy grade contains

Carbon : 0.40 %

Manganese : 0.70 %

Nickel : 1.85 %

Chromium : 0.80 %

Molybdenum : 0.25 %

SRI/ TM / 43 /I01/ R 01/ 25 2014Pg: 2.Medium Alloy Steel:

A group of (mostly) proprietary alloys with somewhat better corrosion resistance that stainless steels are called medium alloys. Thesealloys have extensive applications in sulfuric acid system. Because oftheir increased nickel and molybdenum contents that are more tolerant of chloride-contamination than standard stainless steels.

3. High Alloy Steel:

The groups of materials called high alloys all contain relativelylarge percentage of nickel.

SRI/ TM / 43 /I01/ R 01/ 08 JUL 2014Pg: STAINLESS STEEL

Stainless steels are high-alloy steels and have superiorcorrosion resistant to the carbon and conventional low-alloy steelsbecause they contain relatively large amount of Chromium.

CLASSFICATION OF STAINLESS STEEL Austenitic:In austenitic steel metal atoms are arranged in Face Centered Cubic (FCC)

Feritic:In ferritic steel metal atoms are arranged in Body Centered Cubic (BCC)

Martensitic:In martensitic steel metal atoms are arranged in Body Centered Teragonal (BCT)

ENGG.MATERIALS ORGANIC METALS CERAMICNON-FERROUS METALS FERROUS METALSWROUGH IRON WROUGHTSTEEL

CAST IRON PIG IRONSTAINLESS STEELALLOY STEELCARBONSTEEL LOW C.S MEDIUM C.S HIGH C.S HIGH A.S MEDIUM A.S LOW A.S MART ENSITIC FERITIC AUSTENITI

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