Gas Metal Arc Welding (GMAW) Flashcards

Questions and Answers

Define and describe the GMAW process in detail.

Joins metal by heating them with electric arc established between a continuously fed filler metal electrode and the workpiece.

The gas metal arc welding process is also known as:

Robotic Welding

Stick Welding

TIG Welding

MIG Welding (correct)

GMAW is recommended for use on which of the following metals?

Steel

Aluminum

Stainless Steel

All of the above (correct)

List the basic equipment components required for the set-up of GMAW outfit.

Volts and wire speed. Signup and view all the answers

How will penetration be affected when stickout is increased?

Will decrease penetration Signup and view all the answers

Changing the gun inclination will:

Cause the wire to feed unevenly Signup and view all the answers

Describe how GMAW equipment is likely to behave when the contact tip is worn out.

Cause gas flow turbulence, resulting in porosity and poor quality welds. Signup and view all the answers

Excessive splatter build up in the gun nozzle can cause:

Inadequate gas coverage Signup and view all the answers

Moisture and dirt on the surface of the wire electrode is likely to cause:

Porosity Signup and view all the answers

Excessive drag from a dirty liner is likely to cause:

Damage to the liner and contact tip Signup and view all the answers

When arc hunting occurs, the problem is likely in the:

Wire feeder drive motor or the motor gearbox Signup and view all the answers

Stubbing is caused by excessive:

Wire feed speed Signup and view all the answers

List four causes of porosity.

Lack of gas coverage, wet shielding gas, excessive tip to work distance, excessive gas flow. Signup and view all the answers

Describe what whiskers are and how they are caused.

Whiskers are lengths of unmelted electrode wire welded to and protruding from the root side of an open root groove weld. Signup and view all the answers

Describe the procedure for clearing a bird nest.

<ol> <li>De-energize the power source and feeder, 2. Cut the wire at the back end of the cable liner, 3. Remove the contact tip, pull the wire through the gun and cable assembly, 4. Clean or replace the liner and/or contact tip, 5. Relieve tension on or remove the idler rolls, 6. Remove bird nested wire, check for damage to drive roll assembly, 7. Tie off wire to spool.</li> </ol> Signup and view all the answers

How often should you clean the conduit liner of wire drive setup?

Every time the wire spool is changed Signup and view all the answers

What should you do when the liner becomes kinked?

Cut the kinked portion out and rejoin using manufacturer approved fittings Signup and view all the answers

List six things you should check for if the arc becomes unstable.

Loose cable connections, badly worn or dirty contact tip, loose work lead connection. Signup and view all the answers

What can result from a poor work lead connection?

An unstable arc Signup and view all the answers

List four things you should check for when you see porosity in the weld when using GMAW.

Increase gas flow, use wind break, spatter buildup from nozzle, leaks, kinks, disconnected or blocked gas lines, frozen regulators. Signup and view all the answers

The use of shielding gases for GMAW increases the need for:

Good ventilation Signup and view all the answers

High ultraviolet radiation emissions from GMAW can cause atmospheric oxygen in the vicinity of the arc to convert to:

Ozone Signup and view all the answers

A potential source of poisonous chemical fume when welding is:

Chlorinated degreasing solvents Signup and view all the answers

Study Notes

Gas Metal Arc Welding (GMAW) Overview

GMAW, also known as MIG welding, joins metals using an electric arc between a continuously fed filler metal electrode and the workpiece.
Recommended for use on various metals, making it versatile for different applications.

Equipment and Setup

Basic components required for GMAW include voltage settings and wire speed adjustments.
Importance of equipment maintenance is highlighted, especially monitoring the condition of the contact tip to prevent gas flow turbulence.

Welding Process Considerations

Increasing stickout will decrease penetration in welds.
Gun inclination affects both penetration depth and the feeding smoothness of the wire.
Managing excessive splatter and dirt build-up in the gun nozzle is crucial to ensure adequate gas coverage during welding.

Common Issues and Solutions

Moisture and dirt on the wire electrode can cause porosity in welds, compromising quality.
Dirty liners can lead to excessive drag, damaging the liner and contact tip.
Arc hunting indicates potential issues with the wire feeder drive motor or gearbox.

Porosity and Defects

Common causes of porosity include insufficient gas coverage, wet shielding gas, excessive tip-to-work distance, and high gas flow.
Whiskers are unmelted wire protrusions from the groove, often caused by an incorrect root opening or face thickness.

Maintenance Procedures

Clearing a "bird nest" requires de-energizing equipment, removing the wire, and cleaning or replacing parts as necessary.
Liner cleaning should occur every time the wire spool is changed; kinked liners must be replaced or repaired using approved fittings.

Addressing Unstable Arcs

When experiencing an unstable arc, check for loose cable connections, worn contact tips, and secure work lead connections.
Poor connections can lead to unstable arcs.

Troubleshooting Porosity

Solutions for porosity issues include increasing gas flow, eliminating spatter buildup, and ensuring gas lines are clear of leaks.

Safety Considerations

The use of shielding gases in GMAW necessitates good ventilation to ensure safety during operation.
High ultraviolet radiation from GMAW can convert atmospheric oxygen into ozone, posing additional health risks.
Chlorinated degreasing solvents are a source of poisonous fumes, underscoring the need for proper safety measures.

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Description

Test your knowledge of Gas Metal Arc Welding (GMAW) with these flashcards. Discover the definitions, processes, and applications of GMAW, also known as MIG Welding. Perfect for students and professionals looking to strengthen their understanding of this welding technique.