Troubleshooting the GMAW Process
Although many people tout gas metal arc welding (GMAW) as an "all-in-one" solution, that doesn't mean it's a magic remedy for eliminating your welding problems. this article examines common pitfalls encountered during the normal course of GMA welding, along with trusted ways to correct them.
Porosity is a small pocket of gas caught in the weld metal that can appear at any specific point on the weld or along its full length. This discontinuity — whether internal or on the surface of the weld bead — significantly weakens the structural integrity of any weld.
Inadequate shielding gas coverage is a common cause of porosity and is easily corrected by taking some or all of the following measures.
B. Morrett and G. Giese
Exposition Proves to Be a Technology Showcase
The first combined FABTECH International & AWS Welding Show was celebrated with a special ceremony resoundingly inititated by the Chicago Bucket Brigade, a group of youths who used plastic 5-gal buckets as drums to beat out a driving, rhythmic cadence that attracted a large crowd in the reception area. Dignitaries from the city of Chicago, the state of Illinois, the Society of Manufacturing Engineers (SME), the American Welding Society (AWS), and the Fabricators and Manufacturers Association (FMA) welcomed the attendees.
Gus Geraldo representing Chicago Mayor Daley spoke of how important this show is to the city, and of the many programs the city has that support manufacturers and workforce training. Art Ludwig from the Dept of Labor, state of Illinois, presented a proclamation signed by the governor recognizing the contribution of the FABTECH International & AWS Welding Show to the betterment of manufacturers and declaring the week as "Manufacturing Week in Illinois."
Gene Nelson, president SME, Damian Kotecki (fig...1), president of AWS, and Joe Mayer, FMA chairman of the board, all spoke of the cooperative effort and teamwork that was exhibited by the three societies to bring the combined show to fruition.
A. Cullison, M. R. Johnsen, and K. Campbell
Monuments in Metals - The Olympic Artist's Tale
During a business meeting with members of the U.S. Olympic Committee, renowned sculptor Jon Hair sketched on a table napkin his ideas for a metal sculpture embodying the spirit of the Olympic Games.
Hair said, "I envisioned a powerful sculpture, one that would capture both the eye and imagination. The one image that kept coming into my mind was Atlas, holding up the earth. I saw this as a universal symbol epitomizing the essence of strength." Hair sketched four athletes, facing in different directions, supporting the world on their backs.
H. M. Woodward
Improve GMAW and GTAW with Alternating Shield Gases
Arc welding using helium (He) as a shielding gas was developed in the 1920s. Afterward, argon (Ar) and CO2 were introduced as other commonly used shielding gases. Each shielding gas has its own properties, including ionization potential, and produces unique arc characteristics (Refs. 1-3). Beginning in the early 1970s, researchers (Refs. 4, 5) reported benefits from using a mixture (premixed) of two gases. since then, American welding industries have not seen significant evolution in the use of shielding gas to improve quality and productivity of gas metal arc (GMA) or gas tungsten arc (GTA) welding.
Y. H. Chang
His Fantasies Flare to Life in Metal
A remarkably skilled welder Kacey "Ace" Cordell, 22, is making a name for himself in the Dallas, Tex., area, for his unique metal sculptures.
His whimsical gigantic fire-breathing dragon sculpture (lead photo and Fig. 1) is on permanent exhibit at Mountain View College in Dallas. And his fantastic metalworks IS the atmosphere at Reno's Chop Shop Saloon, a bikers' hangout in the heart of Dallas's Deep Ellum district.
The First Big Breaks
"Before opening the bar two years ago, Reno's asked me to "do something creative,'" Cordell said. he allowed his imagination to run free with his concepts of what bikers might like: hot flames, spider webs, and skull motifs wooven with intricate detail throughout the entire building - Figs. 2, 3.
H. M. Woodward
WELDING RESEARCH SUPPLEMENT
*Ranking the Resistance of Wrought Superalloys to Strain-Age Cracking (.pdf)
The controlled heat rate test was used to rank the crack resistance of several higher-strength alloys
M. D. Rowe
and Numerical Simulation of Restraining Forces in Gas Metal Arc Welded
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WELDING JOURNAL - February 2005, Volume 85, Number 2