Objective:

Currently, out-of-position welding of CuNi 90/10 piping in Naval ships can only be performed adequately by gas-tungsten arc welding (GTAW) using the required RN-67 (CuNi 70/30) electrode. Pulsed gas-metal arc welding (GMAW-p) using an EN67 electrode has some limited success in out-of-position welding but is normally welded in the flat position because of the high liquidus temperature of the CuNi 70/30 electrode and the high thermal diffusivity of the CuNi 90/10 piping.

The objective of this study was to determine the feasibility of developing an out-of-position electrode for high-production flux cored arc welding (FCAW) of CuNi 90/10 pipe. This one-year investigation has proven that it is feasible to develop an all-position CuNi 70/30 flux cored electrode (identified as EN67T-1) for FCAW of CuNi 90/10 piping in order to virtually double welding production in the shipyard. Initial results showed that the operability of experimental EN67T-1 flux cored electrodes was promising in the flat position.

Final Report – Approved for public release; distribution is unlimited

Overview

Welding Technology

Project Team:

  • Portland State University
  • General Dynamics NASSCO
  • Thermadyne/Stoody
  • Cor-Met

2004

NSRP ASE Investment: $100K