Print this page Overview of Arc Welding Fundamentals
A. Bhatia, B.E.
Course Outline
Welding is a challenging and dynamic profession that is in high demand; not limited to one industry or geographical area. This 4-hour course will introduce you to the fundamental knowledge of arc welding that is considered essential for entry into the welding and fabrication field. It discusses the structure and properties of both the weld metal and the heat affected zone. It explains the necessity for edge preparations when butt welding, and gives examples of the types used. It outlines how the welding procedure can be varied to meet the needs of the particular joint being made.
This course includes a multiple-choice quiz at the end, which is designed to enhance the understanding of the course materials.
Learning Objective
At the completion of this course, the student will:
- Name and describe the four basic types of arc welding processes and tell what factors influence their selection;
- Explain how the SMAW, GMAW, GTAW and SAW techniques work;
- Learn how to properly select the shielding gases in arc welding operations;
- Understand the technical vocabulary of welding as applicable to different types of joints and welds;
- Define the heat-affected zone and tell what changes can occur there during welding;
- Describe the effects of uneven or rapid heating and cooling on base metals and weld beads;
- Explain the benefit of preheating and when it should be used;
- List the factors affecting the quality of welded connections;
- Understand the importance of welding procedures;
- Describe effective cross-checking and NDE techniques;
- Understand how to interpret welding drawing, lines, dimensions, symbols and notes to communicate ideas on paper; and
- Describe the personal protective equipment necessary for welding.
Intended Audience
This course is aimed at students, mechanical, structural and process engineers, facility managers, H & S professionals, environmentalists, energy auditors and anyone who wants a basic understanding of welding principles.
Benefit to Attendees
Qualified welders are needed in different branches of metal and building industries, as well as in car – and shipbuilding industries. This welding course provides prospective tradesmen with the basic understanding of the theory, principles, methods, and techniques related to modern arc welding.
Course Introduction
Simply stated, welding is a joining of materials, usually metals or thermoplastics, by causing coalescence. This is often done by melting the workpieces and adding a filler material to form a pool of molten material (the weld pool) that cools to become a strong joint, with pressure sometimes used in conjunction with heat, or by itself, to produce the weld. This is in contrast with soldering and brazing, which involve melting a lower-melting-point material between the workpieces to form a bond between them, without melting the workpieces.
This 4-hour course will introduce you to the fundamental principles of arc welding. Note that this course is not a substitute for a proper apprenticeship.
Course Content
This course is in the following PDF document:
Overview of Arc Welding Fundamentals
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Course Summary
The American Welding Society (AWS) defines welding process as "a materials joining process which produces coalescence of materials by heating them to suitable temperatures with or without the application of pressure or by the application of pressure alone and with or without the use of filler material". The arc welding group includes four basic processes, each separate and different from the others but in many respects similar.
The shielded metal arc welding (SMAW) process is the simplest arc welding process which produces coalescence of metals by heating them with an arc between a covered metal electrode and the work-piece. Shielding is obtained from decomposition of the electrode covering. Pressure is not used and filler metal is obtained from the electrode.
Automatic welding was made popular on introduction of submerged arc welding (SAW) process. Pressure is not used and filler metal is obtained from the electrode and sometimes from a supplementary welding rod." It is normally limited to the flat or horizontal position.
Gas tungsten arc welding (GTAW) also known as TIG welding process uses non-consumable electrode tungsten. The process is extremely suitable for non-ferrous metals particularly magnesium and aluminum. Another related process known as gas metal arc welding (GMAW) also called MIG welding uses a continuous filler metal (consumable) electrode for arc. Shielding is obtained entirely from an externally supplied gas or gas mixture.
Many different energy sources can be used for welding, including a gas flame, an electric arc, a laser, an electron beam, friction, and ultrasound. While often an industrial process, welding can be done in many different environments, including open air, under water and in outer space. Regardless of location, however, welding remains dangerous, and precautions must be taken to avoid burns, electric shock, eye damage, poisonous fumes, and overexposure to ultraviolet light.
Quiz
Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.
DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDH Center or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered architect and/or professional engineer/surveyor. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.
