GTAW and TIG Welding Standards

Introduction

GTAW or gas tungsten arc welding is generally a manual welding process. Gas tungsten arc welding is also called TIG welding, short for tungsten inert gas welding. It uses a tungsten electrode. GTAW often uses alternating current while using argon or helium as a shielding gas.

What are the pros and cons of GTAW or TIG welding? What industrial standards apply to GTAW and TIG welding?

Gas tungsten arc welding or GTAW, also called TIG welding, is one of the few welding methods that work on almost any metal.
Gas tungsten arc welding or GTAW, also called TIG welding, is one of the few welding methods that work on almost any metal. | Source

Advantages of GTAW or TIG Welding

What are the advantages or pros of gas tungsten arc welding?

  • GTAW allows you to join metals that are dissimilar. It works on almost all metal alloys. Gas tungsten arc welding is one of the few options for welding metals like titanium, magnesium alloys and refractory alloys and the only option for welding different nonferrous alloys together.
  • It does not create slag or splatter. And less cleaning is required after the welding is complete.
  • TIG welding allows you to work in all possible weld positions.
  • Gas tungsten arc welding works well on thin metal pieces, yielding greater precision than GMAW.
  • GTAW generates fewer inclusions.
  • GTAW sometimes does not require filler metal. This is called autogenous welding.
  • GTAW can be performed with lower cost power supplies than other welding methods require.
  • Gas tungsten arc welding lets you control the heat source and addition of filler metal separately.
  • Gas tungsten arc welding offers fair joint accessibility.
  • Weld quality is higher than many other types of welding, but this requires clean plate.
  • TIG welding has a high deposition efficiency.


Disadvantages of GTAW

What are the disadvantages of gas tungsten arc welding, also known as GTAW welding?

  • GTAW has a lower tolerance for filler contamination than other types of welding.
  • A higher level of welding skill is required.
  • More expensive welding equipment is required than for other types of welding.
  • Gas tungsten arc welding is slower than other types of welding, since it has a lower deposition rate. Argon makes it easier to see the weld. However, when helium is used, the weld penetrates more deeply, so the welding job may go faster.
  • The tungsten electrodes may be contaminated if it touches a work piece while the arc is being initiated.
  • The solution to this is using separate starting circuits with high frequency power. The high frequency power cables involved may interfere with surrounding electrical equipment.
  • If you are working with low carbon steel, GTAW only works on killed steels, not rimmed steels. GTAW is not recommended for cast iron.
  • The weld area has to be protected from drafts, since the gas envelope must be intact to prevent inclusions or contamination. This limits the use of gas tungsten arc welding outdoors.
  • If you are working with low carbon steel, GTAW only works on killed steels, not rimmed steels. GTAW is not recommended for cast iron.
  • The GTAW weld area has to be protected from drafts, since the gas envelope must be intact to prevent inclusions or contamination. This limits the use of gas tungsten arc welding outdoors.
  • If the electrode touches the weld pool, tungsten inclusions will form.

GTAW and TIG Welding Standards

American Welding Society standard AWS C5.5 gives the recommended practices to be followed during GTAW welding such as proper gas shielding, joint preparation and quality control for welded joints. AWS C5.5M is the metric version of this standard. AWS C5.5 and AWS C5.5M are both ANSI approved standards. AWS A5.30 gives the material specifications for the weld inserts used for gas tungsten arc welding.


ASTM International has also issued standards for gas tungsten arc welding. ASTM B547-10 is the standard for arc welded round aluminum tube, including that created by gas-tungsten arc-welding. ASTM E1648-95 outlines the process for examining welded aluminum using radiographs.


Military specification MIL-STD-2104 was the Department of Defense standard for gas tungsten arc welding, but standard has been cancelled.

SAE AMS 2685E was issued by the Society of Automotive Engineers; while this standard was issued in 2002, it stopped being the recommended standard for GTAW in 2007.

More by this Author


Comments 1 comment

dbworx profile image

dbworx 4 years ago from So. California

Hey Tamara, good post... I'm not the best tig welder out there but, you have brought up some great issues. Good work.

    0 of 8192 characters used
    Post Comment

    No HTML is allowed in comments, but URLs will be hyperlinked. Comments are not for promoting your articles or other sites.


    Click to Rate This Article
    working