Page 36 - MetalForming June 2016

Welding:
How to Choose the Right Solid Wire
Solid wire is one of the most-used filler metals in the welding industry the world over, and is a common choice for applications ranging from home hobbyists to general maintenance to repair. It can be used to weld many types and thicknesses of materials, from very thin alloys to thick structural metals for steel buildings.
Solid wire is simple to use, making it a popular choice across welding applications. But given specific materials and applications, which wire is best? Read on to find out.
BY JONATHAN WILL
No two welding operations are the same. Yet in many cases, companies come to rely on sim- ilar filler metals to get the job done. Solid wire is among the most widely used filler metals in the industry and is a common choice for applications ranging from general fabrication and manufacturing to maintenance/repair and pipeline welding.
Jonathon Will is product manager at Hobart Bros. Co., Troy, OH; 800/626- 9420, www.hobartwelders.com.
The wire’s ease of use contributes to its popularity, as does its ability to weld many types and thicknesses of materials. Welding technology available on the market today also makes it easier for welding operators of varying skill sets to create quality welds with solid wire.
As with any type of filler metal, keep in mind several considerations when choosing a specific solid wire for an application. Different classifications offer varying characteristics for each solid wire, all of which can impact weld strength and quality, as well as the amount of post-weld cleanup needed.
Solid Wire: An Overview
The American Welding Society (AWS) provides multiple classifications for solid wire based on the mechanical and chemical properties each provides. Each letter and number in its nomen- clature signifies a specific feature. As an example, for a commonly used solid wire, AWS ER70S-6, the “ER” indicates that the filler metal is an electrode or rod; the “70” signifies that it has a ten- sile strength of 70,000 lb./sq. in. (psi); and the “S” means that it is a solid wire. The “6” reflects the chemical compo-
sition and shielding gas requirements. Solid wires with “S-3” and “S-6” suf- fixes are among the most commonly used in the industry for gas-metal-arc welding (GMAW ). For gas-tungsten-arc welding (GTAW ) applications, an ER70S-
2 cut-length (or rod) often is used. Solid wires are available in a range of diameters. For GMAW, diameters range from 0.023 to 1⁄16 in., whereas solid wires used in submerged arc welding (SAW ) can have diameters to 1⁄8 in. and larger. GTAW cut-lengths are available in diameters of 1⁄16 to 5⁄32 in. Typical operating parameters for solid wire depend upon these diameters and, for GMAW or SAW, also on wire-feed speed. Wire-feed speed is proportion- al to the amperage used for the welding application. Voltage can range from 14
to more than 30 V.
When using solid wires, spray trans-
fer and short-circuit transfer are two common welding modes. The transfer mode used for an application depends upon the shielding gas and the welding parameters. To achieve spray-transfer mode requires a minimum of 85 per- cent argon in the shielding-gas mix- ture. The result of this mixture is less
34 MetalForming/June 2016
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