Many variables need to coalesce correctly to create a proper weld. Welders should be aware of the impact that welding technique, travel speed, heat input, operating parameters and gas flow have on the robustness of a weldment.
When the weld is not meeting standards, the first rules of thumb are to ensure that the welding procedure is being followed and that the welder is operating within the manufacturer’s recommended data sheet parameters. In addition to mechanical requirements, however, an often-overlooked factor when selecting the right filler metal is the welding wire’s forgiveness, commonly referred to as “weldability.” Construction/fabrication, known in the industry as confab, is just one example of an industry segment that prioritizes weldability in its operations.
Selecting a filler metal that not only meets the specifications of the application but also has good welding attributes can help minimize weld defects as well as pre- and post-weld activities – and it can even aid new welders in producing quality welds sooner. That translates to more arc-on time, enhanced productivity and mastery of the skill of welding even more rapidly.
Importance of weldability
At its most basic, weldability is how easy the welding wire makes the welder’s job. To break down the subjectivity of weldability, generally five criteria are used to assess this attribute:
- Arc stability: How smooth, consistent and controlled the arc remains during welding
- Bead appearance: The bead should be uniform and properly fused to the base metal with minimal undercutting, cold-lap or concavity/convexity
- Spatter level: The amount of spatter expelled from the weld pool
- Slag removal or silicon control: How easily the slag detaches from the weld (flux-cored) or how easily the silicon gathers and is removed from the weld surface (metal-cored/solid wire)
- Range of operability: How accommodating the wire is to a wide range of parameters and welding variables
Failure to select a wire that aligns with those criteria increases the risks of weld discontinuities and defects – which can lead to time-consuming and costly cleanup and rework. For newer welders, working with an unwieldy wire can expose their novice skillset, which is not only discouraging but also amounts to lower quality welds and compromised productivity.
Welding wire with a high weldability factor is manufactured with premium materials and meets strict quality standards. Up front, this wire may be more expensive, but what it saves in weld prep, rework and quality can have positive financial impacts across an entire operation.
For newer welders, high-weldability wire has the potential to aid them in laying a quality weld even if they are slightly off in some of their settings or technique. Of course, parameter and technique mastery are the goals, but as newer welders work to improve their skills, a wire with good weldability provides them a more flexible range of operability that can help them produce quality welds.
Filling the confab space
High-weldability wire is necessary no matter the industry, but for operators in the confab space specifically, selecting a wire that has ample strength and toughness while standing up to environmental factors is crucial. There are several classes of wire that seamlessly marry weldability and the mechanical requirements necessary to meet the demands of confab applications, such as the D1.8 seismic code.
Self-shielded flux cored. For self-shielded flux-cored arc welding (FCAW-S) wire, an E71T-8 wire, such as Fabshield XLR-8, provides all the weldability benefits while also gaining significant productivity over a SMAW process. This wire is ideal for single or multi-pass welding as well as for multiple positions – all while providing sound mechanical properties and versatility and eliminating the need for shielding gas in the field.
Gas-shielded flux cored. Gas-shielded flux-cored arc welding (FCAW-G) wire requires an external shielding gas to fully protect the weld pool. It is commonly used for welding carbon steel and low-alloy steels in heavy fabrication and construction. A go-to classification in the under-roof or in-shop confab space is E71T-1 wire. This classification of wire provides some of the most forgiving weldability characteristics in wire selection. Its versatility makes it ideal for various material thicknesses and it is designed for all positions, making it a flexible option for many types of applications.
Two examples of high-weldability staples in the industry are the FabCo Excel-Arc 71 and FabCo Triple 7 wires. As all-position wires, they work well for single and multi-pass applications and are effective with pure CO2 or argon/CO2 gas mixes. Exceptional weld pool control makes for consistent out-of-position welds, and the consistent arc transfer creates a flat bead profile for a high-quality and aesthetically pleasing weld. Both options minimize spatter levels, facilitate easy slag removal and can bridge poor fit-up without burnthrough.
Metal cored. Metal-cored wire is also a great way to speed up productivity and maximize efficiency in the confab space. A common classification is E70C-6M. This wire is designed for mixed gas composition, so it can be used in an under-roof or in-shop space. A wire like FabCor Elevate, the latest in metal core technology, provides cutting-edge deposition without sacrificing any weldability.
For in-position welding, a metal-cored wire like FabCor Elevate can replace a large-diameter flux-cored wire in some applications and eliminate slag coverage, which means no more chipping and less shop cleanup. This wire is designed to gather silicon at the center of the weld for minimal cleaning. Using a wire brush typically takes care of the silicon islands that remain, and sometimes they even fall off on their own as the weld cools.
Recognizing need
Selecting a welding wire with good weldability is often an under-recognized element of productivity. Good weldability leads to productivity via a streamlined, more efficient welding process, reducing the likelihood of defects and rework. This not only saves time, but also lowers the costs associated with material waste and labor.
For newer welders, a wire with good weldability provides a more forgiving and manageable welding experience, allowing them to develop their skills more effectively and with greater confidence. In emphasizing weldability at the onset, companies can achieve the ultimate trifecta: higher quality welds, improved overall efficiency, and support for the growth and development of their workforce.
