Understanding TIG Electrodes: How to Choose the Right Type

The most frequent query about TIG welding is, "What tungsten do I use?" We are all aware that welding equipment is always evolving. A rectifier machine used to be the most widely utilized power source in history. Inverter-based technology is more prevalent nowadays, giving the welder greater control over the arc.

The welding process known as Tungsten Inert Gas, or TIG, employs a non-consumable tungsten electrode to create a weld. The procedure, often referred to as Gas Tungsten Arc Welding (GTAW), is frequently employed in welding applications that call for precise and superior welds.

The various forms of TIG welding, how to choose the best tungsten electrode type, and efficient TIG welding techniques will all be covered in this article. But first, let's review some fundamentals about tungsten Electrodes.

WHAT IS THE PURPOSE OF TUNGSTEN?

TIG welding is one of the several industrial uses for the metal tungsten. Because of its high melting point, it is prized as a perfect material for the several kinds of tungsten electrodes used in welding. Additionally, tungsten is utilized in the manufacture of X-ray tube filaments, electrical connections, and incandescent light bulb filaments.

TIG WELDING TYPES

TIG welding has historically been divided into two primary types: AC and DC.

Alloys made of magnesium and aluminum are welded using AC welding. The electrode and the workpiece both receive balanced heat output from this welding process. Good penetration and a stable arc are the outcomes of this.

Steel, stainless steel, and other metals can be welded with DC welding. The workpiece receives a higher heat output than the electrode. This makes it easier to fuse thicker metals.

Despite being in use for decades, these two TIG welding types—each using a distinct (and conventional) tungsten electrode type—are no longer frequently employed in contemporary TIG welding procedures. Better, superior mix electrodes have taken the place of the pure tungsten used for AC and the tungsten + 2% thorium used for DC due to modernization and the full switch to inverter-based power sources.

CHOOSING THE PROPER TYPE OF TUNGSTEN ELECTRODE

A variety of tungsten electrode types are available, and selecting the appropriate one is crucial to creating TIG welds of superior quality. Before choosing a tungsten electrode, you need to ascertain a few things, including:

• The kind of material being welded
• Weld type
• Output of welding (AC or DC)
• Thickness of material
• Range of amperage
• Type of welding power source: transformer, rectifier, or inverter

With the electrode negative, direct current will be used to weld metals including copper, brass, titanium, stainless steel, carbon steel, and chromoly. Alternating current (AC) is typically used to weld aluminum alloys.

Pure tungsten (green stripe) was the best choice for AC welding for a long time. However, when the industry moved to invert-based machines with sophisticated squarewave technology, rare earth tungsten, such as Ceriated (gray stripe) and Zirconiated (brown stripe), became available.

The most widely used electrodes nowadays are 2% Thoriated (red stripe). Thorium can carry more current and has excellent arc start properties. However, thoriated tungsten tends to divide and form nodules around the electrode rather than a lovely spherical ball when utilized in the AC mode. You get erratic heat input and an unstable arc in exchange. Additionally, it may result in tungsten spitting, which could introduce impurities into your weld. 

Additionally, choosing the right grind angle, continuous current range, or pulsed current range will affect the electrode current range. For instance, the range of.040 is 2 to 60 amps, that of.093 is 12 to 250 amps, and that of.125 is 20 to 350 amps.

TIPS FOR EFFECTIVE USE OF TIG WELDING

To create high-quality welds, TIG welding demands a high level of ability and accuracy. The following advice will help you make the most of TIG welding:

• To create TIG welds of superior quality, use the appropriate type of tungsten electrode. 
• Make use of the appropriate welding wire for your TIG welding machine. There are numerous manufacturers of welding wire available. 
• Prior to welding, clean the workpiece. Grease, dirt, and other impurities might degrade the weld's quality. 
• Use the right welding technique because only with a steady hand and a consistent welding technique can TIG welding generate high-quality welds.