HiDep Weld Tfillet and Butt Weld Development (2013-452)
- Bollinger Shipyards
- General Dynamics Electric Boat
- Ingalls Shipbuilding
- Gunderson Shipbuilding
- Gatekey Engineering
- MIller Electric
- Hobart Brothers
- Vigor Industiral
August 2013 - February 2015
NSRP ASE Investment: $1.9M
Industry Investment: $627K
To develop procedures and demonstrate the ability of the new HiDep Weld process to reduce distortion and increase productivity in steel plate butt welds and T-fillet welds for shipbuilding applications.
Electric arc plasma is a concentrated heat source that can easily produce enough heat to melt the metal pieces being welded and to melt a wire or electrode. But it is not the ideal heat source for welding because of several problems: 1) the heat is concentrated in one location; 2) much of the energy is lost – radiated as heat and light into the surrounding environment; 3) voltage, wire feed rate, and current cannot be independently varied and so are mathematically coupled making it difficult to produce the “ideal” weld. Over the last three decades, as computing technology has improved, arc welding power supplies have grown more sophisticated, in an effort to use electrical manipulation such as pulsing to provide a more controllable heat source. But, the arc still remains as a less than ideal heat source. An ancillary, but very important consequence of the arc plasma as a heat source for the base material is that the point heat source of an arc does not heat uniformly. The differential cooling causes different parts of the weld to shrink more than others – resulting in residual stress and distortion.
This project will significantly reduce the weld distortion in both butt and T-fillet welds using a new process called HiDep Arc Welding. HiDep uses a low cost induction heat source that is different than, and separately controllable from, the arc heat. Proper design of the induction coil or coils allows the heat to be distributed differently than an arc weld, reducing the differential cooling, which reduces or eliminates distortion. The arc heat is concentrated at the tip of the welding wire electrode and thus is well suited to melting the wire. The second heat source, induction heating, is then used to bring the surfaces of the metal to near the melting point, which can significantly increase the welding speed – doubling or tripling the productivity.
Request Final Report from NSRP – Limited Distribution authorized to U.S. shipbuilding and repair industry and NSRP ASE Program representatives
Point of Contact:
Brent Tompkins, Bollinger Shipyards