Understanding the Basics of Flux-Cored Wires
If you’ve been using a solid wire for your welding processes thus far, chances are that at some point you might have wondered whether or not you should transition to flux-cored wires, especially since they’re the more expensive option. As is the case with almost everything else when it comes to welding, equipping yourself with the basic knowledge about it will help you decide whether something is right for you or not. Consequently, the subject of flux-core wires is no different.
When it comes to welding wire flux core isn’t something new, but still, understanding it can be very confusing without the right source of information. Becoming familiar with the basics can certainly help you shop for a welding wire flux core and be certain of what you’re buying. But more importantly, it can help you work on your welding applications with more confidence. That being said, let’s get right into it.
There are two basic types of flux-core wires: self and gas shielded. Both types feature an outer sheath and are filled with flux and a compound that’s a mix of deoxidizers and alloys. The deoxidizers are essential for protecting the weld from contaminants. Gas-shielded wires require a gas supply to shield the weld, while self-shielded wires do not. Self-shielded wires are ideal for outdoor welding applications because they’re very portable due to the fact that they generate the shielding gas themselves.
Both types are available for horizontal/flat or all-position welding on base materials such as low alloy and mild steel, stainless steel and chrome-moly. When shopping for a flux-cored wire, you’ll see that they’re all labeled with different letters and numbers, all of which have a meaning. For instance, a wire labeled with E71T-11 classifies:
E – Electrode
7 – Tensile strength (70.000 per square inch)
1 – All-position welding (0 would indicate flat and horizontal capabilities)
T – Tubular Wire
1 – The wire’s performance and usability capabilities, including operating parameters
1 – It has no shielding gas
Lastly, worth knowing is that just like all other welding wires, flux-cored wires have their pros and cons. The pros include nice bead appearance, higher deposition rates and their ability to weld very thick materials. Additionally, they have good mechanical properties and can be allowed to match different base metals.
Their one major disadvantage though is the fact that you’ll have to clean up after your weld, as they both produce slag which has to be removed by brushing or chipping between the weld passes, or after the final pass.
