A modified arc cladding process will reduce cycle time and save $1.2 million for the VCS Program. Arc Applications photo
This project was developed to evaluate arc-cladding processes, down-select a candidate process, and demonstrate the ability to qualify the cladding procedure based on NAVSEA Tech Pub 248 requirement.
The current cladding process utilized by General Dynamics Electric Boat (GDEB) in Virginia Class Submarine production is hot wire gas tungsten arc welding (HW-GTAW). The cladding rate of nickel-based materials onto HY-80 and HY-100 components is restricted by heat input, dilution rate and interpass temperature limits.
The developed procedure increased the deposition rate from the present level of 6 lbs per hour to a target level of 10 lbs per hour without degrading the clad quality and while maintaining appropriate final weld layer chemical composition. This project demonstrated that the deposition rate of the HW-GTAW cladding process could be increased to 10.9 lbs per hour with conventional parameter optimization. The introduction of a secondary cold wire feed further increased the deposition rate to 12.8 lbs per hour (72% over the base rate). Tests from both processes met the Tech Pub 248 and GDEB requirements. This increase in deposition rate is expected to result in a savings of $1.2M over the remaining VCS Program. The technology will result in both cost reduction and reduced cycle time.
EB has purchased, installed and began operating the new hot wire GTAW welding equipment, as recommended in the project. Qualification of the NMC-developed, enhanced hot wire (HW) deposition rate practice is scheduled to begin this year in the EB weld lab. Once that occurs, the next planned activity is to purchase a cold wire (CW) feeder and begin to test HW/CW GTAW welding in the EB weld lab.
General Dynamics Electric Boat Corporation
Institute for Manufacturing and Sustainment Technologies
PMS 450 Virginia Class Program Office
Arc Applications, Inc.
Jetline Engineering Arc Machines, Inc.
Special Metals Welding Products