Page 82 - CITS - Fitter - Trade Theory

FITTER - CITS

MODULE 4

LESSON 12: Introduction to welding and metal cutting

Objectives

At the end of this lesson you shall be able to
• explain the various welding process like arc welding and its application and types
• state the gas welding process and its accessories
• state the gas tungsten arc welding and its application
• state the different types of metal cutting process like slotter machine, milling machine and jig boring machine.
Arc welding process and its applications

Various Welding Process
1 Forge Welding: Forge welding is a traditional method where two metal pieces are heated to a high temperature
and then hammered together to form a bond without the use of additional filler material.
2 Metallic Arc Welding: Metallic arc welding encompasses various arc welding processes where an electric
arc is used to melt and join metals together. This includes shielded metal arc welding (SMAW), gas metal arc
welding (GMAW), and gas tungsten arc welding (GTAW).
3 Oxy Acetylene Welding: Oxy-acetylene welding (OAW) uses a flame generated by the combustion of oxygen
and acetylene gases to melt and join metals together. It is versatile and can be used for various metal types
and thicknesses.
4 Tungsten Inert Gas Welding (TIG): Tungsten inert gas welding (TIG) or gas tungsten arc welding (GTAW)
uses a non-consumable tungsten electrode and an inert gas (usually argon) to create a weld. It is commonly
used for welding thin materials and in applications requiring high-quality welds.

5 Gas Metal Arc Welding (GMAW): Gas metal arc welding (GMAW) or metal inert gas welding (MIG) uses a
consumable wire electrode and a shielding gas (usually inert or semi-inert) to create a weld. It is versatile,
high-speed, and suitable for various metals and thicknesses.
6 Electro Slag Welding: Electro slag welding (ESW) is a welding process that uses a consumable electrode
and a granulated flux to create a molten slag pool, which shields the weld zone and facilitates the joining of
thick materials in a single pass.
7 Thermite Welding: welding is a process that uses a chemical reaction between a powdered metal oxide and
aluminium to generate intense heat, melting the parent metals and forming a weld joint. It is often used for
joining railway tracks and large steel structures.

8 Submerged Arc Welding (SAW): Submerged arc welding (SAW) involves the formation of an arc between
a continuously fed wire electrode and the workpiece, while a granular flux covers the arc and weld zone. It is
known for its high deposition rates and deep penetration capabilities.
9 Frictionwelding: Friction welding is a solid-state welding process that generates heat through friction between
two workpieces, causing them to plasticize and form a bond.

when pressure is applied. It is commonly used for joining similar or dissimilar metals.
10 Electron Beam Welding: Electron beam welding (EBW) uses a high-velocity beam of electrons to generate
heat and melt metals together. It is capable of producing precise, high-quality welds in a vacuum environment
and is often used in aerospace and precision engineering applications.
• Definition Of Various Welding Process:
1 Solid State Welding with Pressure:
Solid state welding processes join materials without melting them, using heat and pressure to create a bond.
Examples include friction welding, ultrasonic welding, and explosion welding.

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CITS : CG & M - Fitter - Lesson 11