Tungsten inert gas (TIG) welding is a form of arc welding most commonly used to weld stainless steel, aluminium, magnesium, and copper alloys. No sparks or spatter, flux, slag, smoke or fumes are produced by the TIG welding method.
Types of gas used in TIG welding
The primary gas for TIG welding is argon (Ar). Often helium (He) is added to increase penetration and fluidity of the weld pool.
Argon is what is called a shielding gas. It protects the welding area from oxygen and nitrogen which can cause fusion defects. It’s a colourless, odourless and non-toxic gas.
The thickness of the material to be welded will determine whether other gases such as hydrogen (H), carbon dioxide (CO2), helium (He) and oxygen (O2) are needed to be mixed with the argon. These additional gases will help maintain the quality of the weld in thicker metals.
The gas flow for TIG welding shouldn’t be lower than four litres per minute and can go as high as 12 litres per minute, depending on the specific task.
By adjusting the composition of the welding gas, you can influence the distribution of heat to the weld and by extension, the weld metal cross section and its speed.
Gas mixtures that include helium are often more expensive but result in higher quality results for thicker metal.
The typical Ar/He gas mixture is 25% He to 75% Ar. Any percentage above 25% He tends to create instability at times.
Be informed about TIG welding gas
Before using TIG welding gas for any job, it’s important to identify the best method of welding for the material that is to be welded. This may also inform what gas mix to use.
Once the appropriate method of welding has been chosen, the thickness of the material to be welded should be noted for the purposes of further determining the gas mix and the proportions of the mixture.
Finally, it’s important the correct safety measures are implemented before a job is commenced. Risks include electrocution, radiation, heat and noise.
For information about TIG welding or to order a gas cylinder call Rent Free Gas today on 0404 677 187.