October 15-17, 2024 at Orange County Convention Center in Orlando, Florida
FABTECH Shows ▶
Register
An info icon
A close icon

Join Us in Orlando

Attend Exhibit

Expo Hours

Tuesday Oct 15 9 AM — 5 PM
Wednesday Oct 16 9 AM — 5 PM
Thursday Oct 17 9 AM — 4 PM

Venue

Orange County Convention Center

9800 International Drive
Orlando, Florida 32819

About the Expo

North America's largest metal forming, fabricating, welding and finishing event heads to Orange County Convention Center in October 2024. FABTECH provides a convenient "one stop shop" venue where you can meet with world-class suppliers, see the latest industry products and developments, and find the tools to improve productivity, increase profits and discover new solutions to all of your metal forming, fabricating, welding and finishing needs.

A search icon

North America's Largest Metal Forming, Fabricating, Welding and Finishing Event

From the Blog

Welding Galvanized Steel in the Automotive Industry

By Jennifer Dallos on on
Improved welding methods to join galvanized steel using cost-effective filler materials are demonstrated By Vlad Tudorache, automotive segment manager, Fronius USA LLC, Portage, Ind. Reprinted with permission: The AWS Welding Journal The high demands of the automotive industry today are challenging, and a solution must be considered when faced with welding applications on coated steels. The specific challenges of welding zinc-coated steels (for example, 60G/60G) are driven by vehicle manufacturers’ expectations of being cost effective while maintaining all necessary conditions for a quality product. Many applications are being joined using robotic gas metal arc welding (GMAW) in combination with different variations of filler materials, such as cored and solid wires including brazing wires when gas metal arc brazing (GMAB) is used. With the cost of these filler materials, ranging from three (in the case of cored wires) to five times (in the case of brazing wires) the amount in comparison to solid wires, it is important to identify new technologies and methods to find better ways of joining coated steels while using cost-effective filler materials, such as solid wires, at increased travel speeds. How a New Technology Works For years, the main “method” to robotically weld coated steels with solid wire successfully was to limit the travel speed at approximately 20–25 in./min. This slower speed allowed for more time to burn off the galvanized coating at the leading edge of the weld pool while reducing the speed of solidification and increased time for degassing of the weld pool. At the same time, this reduced travel speed would limit arc disruption enough that spatter would not become uncontrollable during welding. This production method used pulsed gas metal arc welding (GMAW-P) technology offered by various welding equipment manufacturers. With all that considered, what is the solution where cost-effective filler materials can be used in combination with increased travel speeds and generate an increase in productivity? New advancements in arc technology and welding equipment are trying to answer this question through newly developed advanced pulsed technology and dedicated waveforms. With this technology, travel speeds of 40 in./min can be achieved while using solid wires (for example, ER70S-3) and standard shielding gas mixes (for example, 90/10 Ar/CO2) while satisfying quality requirements for porosity and minimized spatter ejection — Fig. 1.

Fig. 1 — Rear axle welded with advanced GMAW-P.

Following Three Factors During experiments and later in production, it became clear that three major factors need to be considered: the usage of low Si solid wire (ER70S-3 vs. ER70S-6), the use of mix gas with low percentages of CO2 (between 8 and 10%), and advanced GMAW-P technology with a specific waveform design (Ref. 1). The relationship between the first two factors is important. The reaction between Si and O2 during welding leads to the formation of silicon oxide (SiO2), which has a higher melting point when compared with the base material (steel). As a consequence of this reaction, weld pool degassing is negatively affected due to zinc’s inability to completely escape the molten pool with the formation of SiO2 on the weld face. The third major factor to be considered while welding galvanized steel is the newly developed advanced GMAW waveform designed for welding coated steels — Fig. 2. This type of technology allows welding on galvanized steels using cost-effective solid wire at increased travel speeds. This is possible due to specific improvements in arc technology such as high-speed data processing on the arc feedback loop. When compared with a standard pulsed arc, the new advanced pulsed technology communication speed is roughly 200 times faster, precisely assisting the droplet detachment inside the arc with a specially designed waveform. Importance of Arc Length and Penetration Stabilizers The fast data processing is key to adjusting the arc, in real time, to compensate for any disturbances caused by vaporized zinc while stabilizing the arc during the whole process. Zinc vapor interaction with the arc is the main spatter generator when welding is done with conventional pulsed processes. Some of the key components of the advanced pulsed process are the arc length stabilizer and penetration stabilizer. The arc length stabilizer maintains the proper arc length during welding, making sure that any changes in the weld environment will not affect the process. The whole process is being controlled and adjusted using “controlled” electrical short circuits included in the pulsed process. As a result, high travel speeds can be achieved without the danger of skipping caused by zinc influences in the arc. The second component of the advanced pulsed process is the penetration stabilizer, which ensures ultra-fast regulation of the wire feed speed to compensate for any extension (contact tip-to-work distance) variations while traveling at high speed. This same function is minimizing the risk of melt-through or nonfusions that cause rework and increase cycle time in automotive welding applications. Conclusion Solutions for the automotive industry’s tendency to down gage, and intensive usage of zinc-coated steel components, will require a desirable one-time investment in new technologies like the one offered by advanced pulsed equipment rather than the continuous expense for specialty filler materials, specialty shielding gases, and costly maintenance from the impacts of cored wires to consumables, thus ensuring proper operation. Nowadays, advanced pulsed technology waveform characteristics for welding coated steel can be used in simpler equipment setup without the need for extra hardware additions as well as difficult-to-maintain/install feedback sensor cables. Advanced pulsed equipment performance proves to be the answer for reduced cycle time, high travel speed, and continued cost reduction when welding galvanized steels in automotive applications. References
  1. Willinger, M. 2014. Welding on HDG Steel. Practical study.
  2. GalvInfo Note 1.3, GalvoInfo Center–International Zinc Association Rev1.2, April 2014.
  3. GalvInfo Note 3.1, GalvoInfo Center–International Zinc Association Rev1.1, April 2011.

2024 Platinum Sponsors

2024 Sponsors

Become a Sponsor