ANNISTON ARMY DEPOT, Ala. - Welders throughout the Nichols Industrial Complex will soon begin certifying to use a new welding process, gas metal arc welding-pulse.
Pulse welding uses more technologically advanced welding equipment than metal inert gas welding or flux-cored arc welding, which are currently used by most of the approximately 250 welders at the depot.
The GMAW-P equipment allows the melting current to pulse, rather than continuously flow. This pulse reduces the required heat input, giving welders better control of heat when welding on hard materials that are prone to cracking, said Bob Stockton, a welding engineer for the Directorate of Engineering and Quality.
"It will mostly eliminate hydrogen embrittlement, or hydrogen cracking," said Randall Holbrook, a depot welding supervisor. "Hydrogen cracking happens when you get water vapor in the metal while you are welding."
During a recent meeting at the Lima Army Tank Plant in Ohio, which is operated by General Dynamics Land Systems, Stockton, Holbrook and other representatives from ANAD were encouraged to begin working with GMAW-P.
"This new process will give us less defects and a better appearance of the welds," said Holbrook.
Welding equipment technology and the welding process application has outpaced current Department of Defense welding procedures, said Stockton. As a result, the installation is currently working with Tank Automotive Research and Development Command on an update to these procedures.
The GMAW-P process has already been approved for ANAD welds on the armor, hulls and turrets of M1 Abrams tanks measuring up to one inch thick. However, a plate measuring one-and-a-half inches thick, which would allow welding of greater thicknesses, has been sent to Aberdeen Proving Grounds for testing.
In Aberdeen, the plate will be subjected to ballistics testing to see how the weld holds up under fire.
"The thicker plate we are having tested at Aberdeen will qualify us for infinite thicknesses," said Stockton.
So far, two ANAD welders are qualified for the new GMAW-P welding method, which uses 95 percent argon - an increase from the 75 percent welders currently use. This increase means the deposited weld metal is cleaner and extra argon makes the cover gas heavier, thus reducing smoke emissions.
"We have ordered some equipment for this new process, but not enough for all the welders yet," said Stockton.
So far, equipment to outfit six welders has been ordered and Stockton said additional equipment would be ordered as welders qualify.
Qualifying to use the equipment should take about three days for employees who have previously qualified with gas metal arc welding. A welder qualification test will be conducted to ensure all welders are able to meet code requirements.
Stockton said this procedure is already in use on M1 Abrams tanks at Lima Army Tank Plant.
"This technology has already proven its worth," said Stockton.
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