CO2 is used in multiple unique ways. You use it to shield the arc against impurities like dust, air, and other gases; heat metal; and ensure the welds are clean on the underside of the seam opposite the arc.
Also, the blanketing gases are used for protecting metal once they go through the welding process. Today, carbon dioxide shielding is widely used in many Australian industries for MIG or metal inert gas welding of carbon steels.
Here are a few reasons why CO2 is used so widely for this process:
Carbon dioxide shielding ensures enhanced joint penetration by providing high arc voltage during welding. This method is effective for achieving success-driven results for root penetration and sidewall.
Low-cost benefits improve its worth among the various other shielding gases. If you use CO2 shielding instead of oxygen shielding, you’ll stop oxidation in the weld metal. As CO2 shielding is heavier than oxygen, it ensures better and enhanced shielding characteristics.
Carbon dioxide comes with a high-temperature arc and dissociates with carbon monoxide and oxygen, which results in oxidation. Given that, slight oxidising may be used for backing strips in GMA welding of carbon steels by declining the polar spots, which otherwise cause unstable arc and spatter at the time of welding.
Blending With Other Gases
During the spray transfer mode, CO2 single-handedly does not provide better results and may even cause serious spatter.
By establishing an association with other gases, CO2 can achieve mutual benefits. For instance, when combined with inert gases like argon, smooth spray transfer is acquired along with low voltage settings. It will also eliminate the issue of arc instability and spattering.
Prevention of Undercut
It’s imperative to know that carbon dioxide is a gas with denser volume and the capability of sound shielding. With the ability to avoid and stop severe weld imperfections like an undercut, this gas is the ideal choice for making good profile weld beads.
Safety and Rust Removal
Safety becomes a priority when it comes to carbon dioxide shielding. Although less hazardous in the workspace, the risky and intricate behavioural pattern of unleashed gases like carbon monoxide can prove dangerous. To make processes safe, you must ensure proper ventilation in the workspace.
You can use carbon dioxide for rust removal from the joint. It prevents rusting by combating rust oxides. In this way, the gas wipes out the other impurities too. Besides the atmospheric protection, this gas prevents weld defects like lack of penetration, fusion, and porosity.
Enhancement in Toughness
During welding, the seamless formation of gases and suitable disposables are the major concerns to generate the requisite toughness in the weld metals. Carbon dioxide, when combined with other gases, also ensures improvement in the toughness of weldment.
Decrease in Surface Tension
Another concern in carbon steels is surface tension, which results in less perforation. The liquified weld gets high surface tension that cannot be decreased by applying inert gases like argon, helium, etc.
CO2 is the only gas capable of reducing the surface tension intensity. It also ensures enhanced penetration outcomes. This enables the shielding gas to be more efficient in carbon steel.
Carbon dioxide has become an essential shielding gas for the welding industry in Australia. However, sourcing this gas in a suitable supply mode has become a challenge for many. So, get in touch with your supplier, and get the most out of your operations.