Span gas online store UK: There are two shielding gases commonly used for arc welding aluminum, and these are argon and helium. These gases are used as pure argon, pure helium and various mixtures of both argon and helium. Excellent welds are often produced using pure argon as a shielding gas. Pure argon is the most popular shielding gas and is often used for both gas metal arc and gas tungsten arc welding of aluminum. Mixtures of argon and helium are probably the next common, and pure helium is generally only used for some specialized GTAW applications.
Overall, argon is a standard, low cost but high-quality choice of shielding to use when welding. Although its odourless and colourless properties make it a convenient gas to use, it can also be dangerous if leaks or overexposure when welding occurs. Never forget that you are dealing with a potentially hazardous element, so entrust installation to a specialist gas installer who knows what they are doing.
Ferric stainless steels used in the likes of exhausts and catalytic converters have high strength and good high-temperature properties, while martensitic stainless steels – used for vehicle chassis and under-carriage components of tractors – are more difficult to weld. A gas for every occasion: Specshield 2.5% CO2 is an excellent general-purpose gas for applications like MIG welding thin automotive parts, such as exhausts, using solid wire. Its mix of argon and 2.5% carbon dioxide gives a good wetting action and produces smooth welds with minimal spatter and low surface oxidation but its fusion is relatively low. Read more info on Calibration Gas Suppliers UK.
A perfect welding result, without impairment of corrosion resistance and mechanical properties, can only be obtained when using a backing gas with very low oxygen content. For best results, a maximum of 20 ppm O2 at the root side can be tolerated. This can be achieved with a purging setup and can be controlled with a modern oxygen meter. Pure argon is by far the most common gas for root protection of stainless steels. Formier gas (N2 + 5 – 12% H2) is an excellent alternative for conventional austenitic steels. The gas contains an active component, H2, which brings down the oxygen level in the weld area. Quad gases are mainly used within Marine environments. Quad gases are a four gas mix. Supplied in a range of lightweight cylinders and made from aluminum. Both reactive and non-reactive mixtures are available.
MAG welding with a carbon dioxide shielding gas or shielding gases containing high proportions of carbon dioxide, e.g. 80%Ar/20%CO2 does not usually present an exposure problem to CO or to any CO2 generated by the process. However, a CO2 asphyxiation problem could arise as indicated above. Similar comment can be made about gas shielded FCAW. Source: www.weldingsuppliesdirect.co.uk.