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How can weld quality be ensured during submerged arc welding with flux? Does welding produce porosity? How should it be used?

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2022-06-06

How can weld quality be ensured during submerged arc welding with flux? Does welding produce porosity? How should the flux be used?

Submerged arc welding flux is primarily used as a welding consumable in electroslag welding, providing excellent welding performance. To ensure weld quality, how should the submerged arc welding process be operated to maintain weld integrity?

1. First, thoroughly prepare the base to be welded by ensuring it is clean, tidy, and relatively flat. Any uneven areas should be ground smooth beforehand to facilitate the application of submerged-arc welding flux.

2. Before use, the submerged-arc welding flux must be preheated, typically at around 200°C for two hours, to ensure thorough heating and enhance its activity. Subsequently, the flux manufacturer advises selecting a welding wire that is compatible with the product in order to shorten the welding time and guarantee weld quality. Given the product’s excellent compatibility and the wide range of suitable welding wires available, the selection process is relatively straightforward; consequently, the price of submerged-arc welding flux has been steadily rising.

3. During the welding process, pay close attention at all times; if any abnormalities occur, stop welding immediately. Ensure that your hand remains steady to maintain optimal results with submerged-arc welding flux.

Can submerged-arc welding flux cause porosity? Let’s take a look.

1. The current used for sintering flux is relatively low, but the power is very high. Coupled with the thermal insulation provided by the flux and slag, this results in exceptionally high thermal efficiency, reduces the amount of filler metal required, and achieves full penetration in a single pass.

2. The welding speed is very high, allowing even steel plates about 10 mm thick to be fully penetrated in a short time. This demonstrates just how fast the process is, which not only saves technicians’ time but also delivers excellent weld quality. Consequently, submerged-arc welding flux has gained widespread popularity.

3. Conventional fluxes typically leave behind porosity after welding, whereas submerged-arc fluxes do not, thereby reducing the likelihood of cracking or weld defects. Consequently, during automated welding, it is highly convenient to make adjustments via automatic control, which is also a key reason for the continuous rise in the price of submerged-arc fluxes.

Since submerged-arc welding flux has been widely adopted, users have gradually come to understand its properties and applications. So, do you know how to use it? Let’s take a look.

1. Many users are unable to control the amount used in a single application, resulting in substantial leftovers of submerged-arc welding flux. Most people simply discard these leftovers, leading to waste—clearly an inappropriate practice. In fact, submerged-arc welding flux is recyclable; manufacturers state that its long shelf life allows for multiple recycling cycles while maintaining consistent performance.

2. According to the manufacturer of submerged-arc welding flux, after use the product can be wiped clean, especially any surrounding slag, as the slag does not adhere to the flux. The flux should then be stored in a cool, dry place for next-time use. However, flux that has already been baked must be used promptly; otherwise, its shelf life may expire or interruptions in use may cause its price to drop.

If you would like to learn more about this topic, please feel free to contact us. We can provide a comprehensive overview from various perspectives.

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