Manual ARC Welding Control
NCMS Project #: 140315
Problem: The United States Marine Corps (USMC) repairs and rebuilds its assault vehicles in the Albany, Georgia, USMC depot weld shop. To minimize weight, some of these vehicles use thick-walled aluminum panels; others use thin-walled steel panels. Joining either of these panel types is difficult and requires a high level of manual welding skill. Flaws in the joint, such as gas pockets or inclusions, are not usually apparent until the results from an x-ray or other tests become available. Any weld section found to contain a flaw must have the weld ground out, replaced, and re-inspected.
This process is unavoidably time-consuming and expensive, but it was the state of the art at the Albany depot as well as in most industrial facilities. The cycle of weld–inspect–weld could be circumvented if the welding process could be certified. In a project previously supported by Air Force ManTech, the enabling technology for weld flaw avoidance, one element needed for process certification, was successfully developed and transitioned into a commercial product.
Benefit:
Technology Transfer: Three major deliverables were supplied to the Albany depot:
- Two complete weld monitoring systems. Unit “a” was installed for training and welder certification. Unit “b” was configured as a portable system to service any welder’s workstation.
- Two helmets equipped with man–machine interface technology
- On-site technical support and training.
Weld monitoring provided these basic benefits at Albany:
- Reduced welding costs
- Effective training and certification methodology.
- ISO-9000 certification of the welding shop.
Potential Readiness Benefits: In one study, one certified welder using the monitoring equipment improved the quality and quantity of his output by $7,000 and saved $3,000 in material, inspection, and rework.
Cost Savings: The total savings per year was estimated at approximately $10,000 per year per welder. This total represents a significant savings for an organization the size of the Albany weld shop.
Solution/Approach: This technology transfer project was to implement the ARC monitor that is a significant step toward process certification for gas metal arc welding at the U.S. Marines Maintenance Center at Albany, GA. By sensing the following four parameters and relaying information to a welder, the monitor helps welders avoid flaws:
- Current
- Voltage
- Gas flow rate
- Weld wire feed rate.
The weld monitor, which is sold under the trade name ARC AgentTM 2000, stores the data of the four sensed parameters in a PC where they are compared to the signature bands of flawless welds. If any parameter drifts out of these bands, the welder is alerted. One alert method provided to the depot was a welding helmet fitted with small red and green light-emitting diodes (LEDs) for the four parameters. If a parameter stays within its signature band the corresponding light stays green. If a parameter strays outside its signature band, the corresponding light turn red, alerting the welder. When the welder responds with welding adjustments and the parameter returns to within its band limits, the light returns to green.
Project purpose was to install and customize ARC AgentTM 2000 systems at the Maintenance Center at Albany, provide on-site training and support, and provide assistance in data-logging documentation for ISO-9000 audit and welder certification approvals.
Impact on Warfighter: Improved quality of welds translates into cost savings in time and materials, but also into increased availability and durability.
DOD Participation:
- U.S. Marine Corps – Albany
Industry Participation:
- IMPACT Engineering
- NCMS