Posted by Marie Poppins on December 16, 2019 in Industrial
Span gas bottle online supplier UK: Shielding Gas for Gas Metal Arc Welding: For GMAW the additions of helium range from around 25% helium up to 75% helium in argon. By adjusting the composition of the shielding gas, we can influence the distribution of heat to the weld. This, in turn, can influence the shape of the weld metal cross section and the speed of welding. The increase in welding speed can be substantial, and as labor costs make up a considerable amount of our overall welding costs, this can relate to a potential for significant savings. The weld metal cross section can also be of some consequence in certain applications.
If you have been in the industry for any length of time, you will know the most common examples. This includes the likes of argon, helium, or carbon dioxide. Each gas offers its own unique properties when welding, and a case could be made for any of them. Carbon dioxide, for example, is low cost. It also makes for inferior welds, letting too much oxygen in. Argon, on the other hand, might be the perfect replacement.
No shielding gas exists that fits all applications. So the first step is to decide what you want to improve in your welding and match this to the benefits the shielding gas can bring. Just remember the gas may change as the thickness of material increases. For example, with components that have to be painted or coated after MIG welding it is important that the amount of spatter produced is kept to a minimum. Using carbon dioxide can cause large amounts of spatter to be ejected from the weld pool damaging the surface of the component. A change to Argoshield Heavy can halve the amount of spatter produced. Moving to Argoshield Universal can halve it again. See extra details on Gas Bump.
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. Calibration gases are split into two categories. These are zero calibration gas and span calibration gas. Calibration gas is used to calibrate gas analyser’s. Calibration gas is in addition used to calibrate Gas detectors. These Gases will also be known as Span Gas and come in a Span Gas cylinder. This product has added one or more component(s).
Welding and cutting activities can generate gases that are hazardous to health. The gas or gases generated and their concentrations depend on the process used and the gas formation mechanisms. Gases, some of which may be hazardous, are inherent in some processes, either as a shielding gas to protect the molten weld pool against atmospheric contamination or, for flame processes, as a consumable that is burnt. Source: weldingsuppliesdirect.co.uk.